AWNING WINDOW UNIT – a combination of frame, one or more operative awning sash weatherstrip, operating device and at the option of the manufacturer screen and/or storm sash assembled as a complete and properly operating unit; unit may contain one or more fixed or nonoperative sash in combination with the operative sash.


BACKBAND – a narrow rabbeted moulding applied to the outside corner and edge of interior window and door casing to create a “heavy trim” appearance; increases both ornamentation and width of the trim.

BALANCED CONSTRUCTION – arrangement of plies in pairs about the core so that the grains of opposite plies are parallel and at right angles to adjoining plies; contains an odd number of plies.

BALANCING – the raising and lowering of sash as well as holding its position at any desired level; sash activation.

BALUSTER – square or turned spindle-like vertical stair members supporting a rail.

BALUSTRADE – a system of rails and balusters usually attached to a stair, balcony or landing for the purpose of providing guard and/or handrail.

BAND MOULDING – a flat decorative or protective strip that is flush or raised above the surface; a moulding somewhat similar to a panel moulding as well as an apron profile; used to trim mantels, china cabinets, etc: “Band Board” is similar to fascia.

BAR – a narrow rabbeted, horizontal or vertical sash or door member extending the total length or width of the glass opening; extends from rail to rail or stile to stile; also called “light bar”; diagonal bars may extend from stile to rail or vice versa.

Bar Moulding – a rabbeted moulding used as nosing for a counter corner, specifically a bar; also bar nosing.

BASE – a moulding applied around the perimeter of a room at the point of intersection of the walls and finish floor; base shoe is generally used with it, forming a two-member base; also baseboard.

Base Moulding – a relatively small moulding applied to the top of the base; when and with a two-member base it forms a three-member base; also base cap.

BASEMENT SASH UNIT – a sash unit, usually of the inswinging or hopper sash type, used for basement of cellar sash openings; usually consists of one, two or three glass lights; may include screens and storm panels.

BATTEN – a moulding run to a pattern on both edges or surfaced four sides to conceal the joint of two adjacent boards in the same plane; also “batts”.

BEAD – a semicircular or rounded profile worked on wood; also a small moulding to secure glass or panels to doors, hence “glass bead.”

Corner Bead – a moulding used to protect corners, especially plastered corners; also corner guard, corner moulding, outside corner.

BETWEEN GLASS – the measurement across the face of any wood part that separates two sheets of glass.

BEVEL – to cut to an angle, other than a right angle such as the edge of a board or door.

BLEEDING – exudation or the coming to the surface of resin or pitch in some species of wood, usually due to temperature or solvents contained in wood finishes.

BLIND – a wood assembly of stiles and rails to form a frame which encloses wood slats; used in conjunction with door and window frames; blinds may contain a panel in combination with the slats or louvers; see DOOR.

BLIND STOP – a sash or window frame member applied to the exterior vertical edge of the side and head jamb in order to serve as a stop for the top sash and to form with the brick moulding and/or casing a rabbet for the storm sash, screens, blinds and shutters.

BOLECTION MOULDING – a moulding that covers the joint between two members with surfaces at different levels and projects beyond both surfaces; also the part of a moulding that projects beyond the surface of a panel; also bilection.

BOLT HOLE PLUG – a small round wood plug used to fill the hole bored into a “stair crook” when joining another crook or stair rail.

BOW – a form or “warp”; deviation flatwise from a straight line from end to end of a piece, measured at the point of greatest distance from a straight line.

BOW WINDOW – three or more individual windows projecting from the wall in a gently curved contour.

BOX BAY WINDOW – a composite of three or more windows, with flanking units projecting from the wall at a 90-degree angle.

BRACE – applied to an assembled window unit to maintain its squareness.

BREAST – the measurement between the outside edges of the casing or pilasters of an entrance or mantel; also “overall width” of the mantel.

BRICK MOULDING – a moulding on window and exterior door frames that abuts the exterior facing material of the structure; serves as (1) the boundary moulding for brick or other siding material; (2) forms a rabbet for the screens and/or storm sash or combination door; also staff mould, staff bed, staff bead, brick casing.

Beaded Brick Moulding – brick moulding containing a bead on its face.

Steel Sash Brick Moulding – a moulding to receive the lip of a steel sash or window and serve as a brick moulding and blind stop; moulding is applied on the head and two sides; also steel sash surround.

BULLNOSE – the rounded end or edge of a wood member, e.g. “bullnose starting stair tread”; often used interchangeably with the term “nosed.”

BUTT – a door “hinge”, one leaf being mortised or routed into the door frame jamb and the other into the edge of the door; incorrectly called a “butt hinge” as the term “hinge” is usually applied to one which is attached to the surface of a door rather than to its edge such as a strap or T-hinge; “butt” consists of the round central part (knuckle), flat portions (leaves or flaps), and the “pin” which is inserted into the “knuckle”; “pin” can be loose pin butt (removable) or “fast” (non-removable).

BUTT JOINT – a joint formed by square edge surfaces (ends, edges, faces) coming together; end butt joint, edge butt joint.


CAP – the upper member of an entrance, wainscot, partition or pilaster; also cap trim, wainscot cap, dado moulding, chair rail cap; also capital.

Dado Cap – the upper edge or top of the wainscot; often analogous to “chairrail” the cap for the dado of the wainscot, hence wainscot cap.

Drip Cap – a moulding to direct water away from a non-masonry-faced structure so as to prevent seepage under the exterior facing material; usually employed over window and exterior door frames and sometimes around the perimeter of the structure immediately above the foundation wall; also “water table.”

Entrance Cap – the portion of an entrance above the door opening; also “entrance head.”

Partition Cap and Shoe – partition cap is a plowed moulding serving as the top horizontal member of a partition; partition shoe is fastened to the floor and serves as the sole plate; it is plowed to receive the partition.

CAPITAL – the head, crowning feature, or topmost structural member of a column, pilaster, or pier.

CAP MOULDING – a moulding sometimes used in conjunction with window or door head casing in order to elaborate on the simple trim design.

CASED OPENING – interior opening without a door that is finished with jambs and trim.

CASEMENT SASH UNIT – a combination of frame, casement sash, weatherstrip and operating device assembled as a complete and properly operating unit; screens and/or storm sash are optional.

CASEMENT WINDOW – windows with sash hinged at the sides; it usually swings open by means of a crank-type hardware system.

CASING – moulded or surfaced-four-sides pieces of various widths and thicknesses for trimming out door and window openings; casing may be classified as “exterior” or “interior” as far as window and exterior door frames are concerned; also classified as “side” or “head” casing.

Door Casing – same as “casing”; may be “interior” or “exterior” door casing; “exterior” door casing installed only on the outside of exterior door frames, especially wood facing wood frame exterior walls; forms with the door jamb the rabbet for the combination or screen door.

Exterior Casing (Outside Casing) – casing to trim the exterior of window and exterior door frames, to serve as the boundary moulding for the siding material, and to form a rabbet with the blind stop or jamb for the screen, storm sash, blind, shutter or combination door; exterior casing is most commonly used on wood facing wood frame exterior walls; three pieces of exterior casing are used for each frame, namely two side and one head; also exterior or outside lining.

Head Casing – the horizontal casing across the top of the window or door opening.

Inner Casing – an entrance member that fits over the outside edges of side and head jamb, thereby providing a base for the pilasters; entrance casing nearest the opening that provides base for pilasters; sometimes architrave.

Interior Casing (Inside Casing) – casing to trim the interior of window and door frames; three pieces of casing are required, namely two of side casing and one of head; also “window or door interior casing”; also inside lining.

Mullion Casing – interior or exterior casing used to trim a mullion.

Outer Casing – entrance casing furthest removed from the opening and which forms a foundation with the inner casing for the pilaster; also “back casing.”

Side Casing – vertical casing on either side of the window or door opening.

Window Casing – same as “casing”; may be “interior” or “exterior” window casing; exterior window casing is most commonly installed on window frames for wood facing wood frame exterior walls; forms with the blind stop the rabbet for the storm sash or screen.

CERTIFIED WOOD PRODUCTS – are those wood products made from lumber harvested in a sustainable manner and certified by a reliable third party. Certified wood products carry a “chain of custody” certificate that tracks the lumber from the forest to the end-user.

CHAIRRAIL – an interior double-stuck moulding originally intended to be applied along the wall of a room to prevent the chair from marring the wall; sometimes used as “hook strip”, batten and “wainscot cap”; also dado moulding, dado rail.

CHAMFER – a corner of a board beveled at a 45-degree angle; two boards butt-jointed and with chamfered edges form a “V” joint or right angle.

COLONIAL – same as “traditional”; of or characteristic of the thirteen British colonies that eventually became the United States; sometimes separated into three periods, namely (1) Early American Colonial 1630-1700, (2) Georgian 1700-1790, and (3) Post-Colonial 1790-1820.

COLUMN – a vertical structure, circular in cross-section, consisting of a base, shaft, and capital; can be weight-bearing as well as ornamental.

COMBINATION STORM SASH AND SCREEN – a frame assembly of stiles and rails (usually 1-1/8″ in thickness) containing a half screen and two glass storm panels; in summer the bottom storm panel is stored in the top of the combination frame and replaced by the screen panel; sometimes called “combination storm sash and screen unit” or simply “combination window unit.”

COMPOSITION FACE PANELS – a door face panel composed of a wood derivative.

CONTEMPORARY – a style of architecture using today’s materials, planning and methods; attention tends to be directed toward present family tastes and needs and free from full reliance on the traditional.

CONVECTION – a transfer of heat through a liquid or gas, when that medium hits against a solid surface. (Usage – “forced convection” takes place outside when winds blow across a window pane; “natural convection” takes place inside when warmed or cooled air moves across the glass surface.)

COPE – to cut or shape the end of a moulded wood member so that it will cover and fit the contour of the sticking coping.

CORE (Solid) – the innermost layer of section in flush door construction. Typical constructions are as follows:

Wood Block/Stave Core – a solid core of wood blocks or strips glued together.

Particleboard – a solid core of wood or other lignocellulose particles bonded together with a suitable binder, cured under heat and pressed into a rigid panel in a flat platen press.

Wood Block, lined – a solid core of two parts: a central wood-block core bonded to two core liners of wood or other lignocellulose materials.

CORE (Hollow) – a core assembly of strips or other units of wood, wood derivative, or insulation board with intervening hollow cells or spaces which support the outer faces. Typical constructions are as follows:

Ladder – a hollow core composed of strips of wood, wood derivative, or insulation board, with the strips running either horizontally or vertically throughout the core area with air cells and/or spaces between the strips and supporting door faces.

Mesh or Cellular – a hollow core composed of strips of wood, wood derivative, or insulation board, interlocked and running horizontally, vertically or diagonally throughout the core area with air cells and/or spaces between the strips and supporting the outer faces.

CORNER BLOCKS, MOULDED – square blocks used in lieu of mitring the side and head casing; “turns the corner” for door and window casing.

CORNICE – the exterior trim of a structure at the meeting of the roof and wall; usually consists of boards and mouldings, namely bed moulding, soffit fascia and crown moulding; may be either “boxed” (closed), “open” or “plain” (simple); also the interior trim at the meeting of the ceiling and sidewalls; also the top part of the entablature.

CORNICE MOULDINGS – mouldings such as crown, bed and cove applied in cornice construction.

CORONA – the vertical structures that overhang a classical cornice, usually having significant projection in order to provide protection for an underlying frieze, the drip stone.

COVE MOULDING – a moulding with a concave profile used primarily where two members meet at a right angle; a rounded inside corner; opposite to a bullnose; also scotia, cavetto, ceiling cornice.

COVE AND BEAD – a moulding profile consisting of a “cove” and a “bead”; also called “cove with a bead”; glass bead or stop.

CRACK PERIMETER – crack perimeter in feet of a door or window opening; also “sash crack perimeter”; for a double hung window, equal to 3 times the width plus 2 times the height.

CROSSBAND – in 5-ply construction the layer of wood between the core and the face.

CROSSBANDED CONSTRUCTION – layers of wood glued together in which each layer has its grain at right angles to adjacent layer or layers.

CROSSBUCK – the panels of a door separated by intersecting diagonal rails and so arranged to simulate a sawhorse, especially one with the legs projecting above the cross bar; an arrangement of panels similar to he Roman numeral “X”; also sawbuck.

CROWN MOULDING – a sprung moulding used where two surfaces meet an angle; usually applied wherever a larger angle is to be covered; also cornice moulding.

CYMA RECTA – a molding or structure having a profile of double curvature, both concave and convex, with the concave part uppermost.

CYMA REVERSA – a molding or structure having a profile of double curvature, both concave and convex, with the convex part uppermost.


DADO – a rectangular groove cut across the grain of a wood member; in contrast to plow; which is cut with or parallel to the grain; in wainscot, the wide portion just above the base.

DENTIL – a series of small square blocks uniformly spaced and projecting like teeth as used in cornice, front entrances and mantels; “dentil” moulding.

DIVIDED LIGHTS – window or door panes separated by bars and muntins.

DOOR – a millwork assembly of stiles, rail and panels which swings, slides, tilts up or folds in order to close an opening in a wall or cabinet; may be exterior or interior, flush or panel type.

Access Door – a small door, often a piece of plywood, to fill an opening in a ceiling or wall and trimmed with door casing; “scuttle door”; leads to plumbing concealed in wall partitions or attic areas.

Batten Door – a door consisting of vertical boards or planking reinforced by horizontal strips or battens; also known as a “common ledged” door; when battens were reinforced by diagonal braces between them, it was termed a “ledged and braced” door.

Bypass Sliding Door – one of two or more sliding doors that bypasses another door(s) in a door opening in a horizontal direction; a complete unit for such a door can be obtained consisting of two side jambs, header assembly with door track attached and necessary hardwood for hanging doors (doors may or may not be included); conserves space due to the exclusion of a required swing space.

Cabinet Door (Cupboard Door) – a flush or panel door used on cabinets.

Combination Door – a door assembly of stiles, rails and sometimes wood panels (usually 1-1/8 inch thickness) containing interchangeable screen and glass storm panel inserts; in summer the glass storm panel(s) is replaced by the screen insert(s); also “combination storm sash and screen door”; usually occupies exterior rabbet of exterior door frame.

Dutch Door – a door, usually exterior, with an upper and lower section that can be opened separately.

Entrance Door – a door on the front entrance of a structure; also “front” or “main” entrance door; may be single or in pairs.

Fire Door – a solid-core flush door incorporating noncombustible material or fire-retardant chemicals to warrant specific fire ratings.

Folding Door – one of two or more sliding doors hinged to move laterally in an opening; “accordion type” door; may be used for a folding partition; a complete unit for folding doors may be obtained consisting of doors with butts applied, track and guide hardware, door pulls and door frame (optional).

French Door – an interior or exterior door consisting of stiles, top and bottom rail and divided glass panels or lights; often used in pairs; “casement” or “terrace” door.

Grade Door – “service door”; derives its name from usual installation of door at grade (the level of the ground at the building).

Hinged Door – an exterior or interior door hung by attaching butts to the stile so that the door swings on a vertical axis; may be single (swinging through 90 degrees) or double acting (swinging through 180 degrees); double-acting doors do not require a door stop; special hinges required.

Louver Door – a panel door with part or all of the panels replaced by louvers; blind door.

Non-Prefit Door – a door requiring further fitting prior to being hung; as opposed to “prefit door.”

Panel Door – consists of stiles, rails and one or more panels, the stiles and rails forming the frame around the panel; “stile and rail” door.

Prefit Door – a door not requiring further fitting or sizing upon installation; “prefit” doors have eased edges and “skid blocks.”

Rim Door – consists of stiles and top and bottom rails and usually containing a single or divided-glass light(s); “store door”; French door.

Sash Door – a panel with one or more panels replaced by glass.

Sliding Door – a door which slides in a horizontal direction parallel to wall of the structure; may be of the “pocket” or “in-the-wall”, “folding”, “accordion” or the “bypass” type.

Store door – similar to rim or French door with a wide bottom rail and usually glazed with one glass panel or light.

Storm door – a panel or sash door occupying the exterior door frame to provide protection from cold weather.

Terrace Door – exterior door, usually generous of glass, opening on the patio or terrace.

Toilet Door – a small louver or panel door with stile extensions (lugs) and hinged as a swinging door; “cafe type” door.

X-Ray Door – a solid-core flush door with one or more continuous sheets of lead fabricated in the door.

DOOR BEVEL – the bevel on the stile edge (lock edge) of a door, usually 1/16″ for doors under 2″ in thickness, so that the door may swing free of the door frame; bevel is approximately 3 degrees towards door stop.

DOOR BUCK – the rough frame door opening; also the jamb studs.

DOOR CLEARANCE – the space between the edge of a door and the door frame which enables the door to properly operate.

DOOR DOUBLER STUDS – studs doubled on each side of the rough door opening to (1) carry wall loads imposed on the opening, (2) provide support for door frame and (3) provide a nailing surface for plaster grounds and door trim or finish; door bucks.

DOOR FACE – the wide flat surface of a door.

DOOR FRAME – a group of wood parts machined and assembled to form an enclosure and support for a door; door frames are classified as exterior and interior door frames.

Adjustable Door Frame – a door frame including an adjustable or sliding jamb which can be used for walls of varying thicknesses.

Bypass Door Frame – and interior door frame to accommodate two or more sliding doors that slide by or bypass each other in a horizontal direction; sliding door frame.

Casing Bead Door Frame – a door frame using a metal casing bead which eliminates the door casing; bead serves as both a plaster ground and casing.

Irregular-head Door Frame – door frame for a non-rectangle opening; the head may be circular, elliptical, Gothic, segment, peak or rake.

Pocket-type Door Frame – an interior door frame to accommodate a door that slides into a partition; pocket-type door frames consist of outside jamb, header assembly with door track attached, split jamb pocket assembly and hardware for hanging door.

Structural Exterior Door Frame – an exterior door frame installed in a conventionally framed (usually 4-foot) wall panel or section.

DOOR JAMB – the part of a door frame which surrounds and contacts the edges of the stiles and top rail of a door; jambs may be classified as (1) “head” or “side” jambs and (2) “plain” or “rabbeted.”

Adjustable Door Frame – a two (sometimes three) piece split jamb consisting of a rabbeted and adjusting jamb section for walls of varying thicknesses; the rabbeted jamb contains a plow to receive the rabbeted edge of the adjusting jamb.

Beveled Door Jamb – a jamb with edges beveled 1/16″ in order to provide a better foundation or bearing for the casing.

Head Door Jamb – the horizontal member forming the top of the door opening and inserted into the dado of the side jambs of the door frame.

Hinge Jamb – side jamb in which the door hinges (butts) are applied.

Plain Door Jamb – a jamb surfaced four sides to which a wood door stop is applied.

Rabbeted Door Jamb – a jamb with a rabbet on one or both edges; if both edges, “double-rabbeted door jamb”; if one edge, “plain rabbeted door jamb.”

Side Door Jamb – the upright or vertical member forming the side of the door opening; the side jamb is generally dadoed to receive the head jamb of the door frame.

Strike Jamb – jamb opposite the hinge jamb; jamb on which the lock or passage set strike plate is installed.

DOOR PANEL – a sheet of thin lumber, plywood or composition material inserted into the frame formed by the stiles, rails and mullions of a door.

Beveled Raised Door Panel – a raised door panel with the edges of the raised face at an angle of approximately 30-45 degrees.

Composition Door Panel – a door panel of material other than solid wood or plywood.

Flat Door Panel – a door panel consisting of a flat piece of plywood, solid wood or other material; contrasted to “raised door panel.”

Hip-raised Door Panel – a raised door panel with the edges of the raised face perpendicular.

Raised Door Panel – a door panel whose face(s) is raised above the panel edges which are moulded and shaped to fit in the grooves of the door stiles and rails; contrasted to “flat panel.”

DOOR SKIN – face panel (usually two or more plies) of a flush door.

DOOR TRIM – the mouldings required to “finish or trim” the side of a door frame consisting of two pieces of side and one of head casing; also side-of-door trim.

DOORWAY – door, frame and trim.

DOUBLE-ACTION DOOR – a door, usually interior, with special hinges or pivots which allow the door to function in both directions.

DOUBLE STUCK – a wood member with both edges moulded.

DUTCH CUT – the meeting point of the lower and upper section on a Dutch door.


EASEMENT – a stair crook whereby the stair rail is curved primarily in a vertical plane; a “ramp”; also easing.

EASEMENT WITH NEWEL CAP – an easement (concave) with a dowel or pin top newel; same as “starting easement”; up easing and newel cap.

EDGE BAND – a strip along the outside edges of the two sides and/or top and bottom of the door.

EFFECTIVE DEPTH OF STAIR STRINGER – the minimum distance from the intersection of the tread and bottom edge of the riser to the lower edge of the stringer; the minimum is between 3-1/2 and 5 inches; also effective depth of rabbet.

EMISSIVITY – the relative ability of a surface to radiate heat, with emissivity factors ranging from 0.0 (or 0 percent) to 1.0 (or 100 percent).

EMITTANCE – heat energy radiated by the surface of a body, usually measured per second per unit area.

END STRIP – an “edge strip” of the top and bottom rails of a door.

ENTABLATURE – the top horizontal structure of an Order in classical architecture, divided into cornice, frieze, and architrave.

ENTRANCE (Front Entrance) – an exterior door frame with or without transom or sidelites with decorative exterior trim; trim may include pilasters, entrance head or cap or a decorative exterior casing.

Entrance Head – the portion of the entrance above the door opening; also entrance cap; entablature; commonly used when head is other than a pediment.

EXTENSION HINGE (Casement Hinge) – a hinge whereby an outswinging sash swings away from the frame to provide a space between the frame and the sash for washing or cleaning from the inside; space provided varies between 2 and 4 inches.

EXTENSION JAMBS – flat parts which are nailed to the inside edges of the window or door frame, so that it will fit a wider wall.


FACE – outer or exposed ply in crossbanded construction; surface from which lumber grade is determined.

FASCIA – a wood member, surfaced four sides, used for the outer face of a “box cornice” where it is nailed to the ends of the rafters and “lookouts”; sometimes refers to the “face” of a mantel.

FEDERAL ARCHITECTURE – a style of architecture, drawing from Palladianism and Georgian architecture, that flourished in the United States from around 1785 to 1820.

FENESTRATION – the placement or arrangement and sizes of the windows and exterior doors of a building.

FILLER STRIP – in a casement sash frame analogous to an extension blind stop; also blind stop; in factory-built kitchen cabinets, strips inserted between wall cabinets and walls or between base cabinets and appliances or between cabinets.

FILLET – a narrow band of wood between two flutes in a wood member; a flat, square moulding separating other mouldings; in stairwork, a thin narrow strip of wood which fits into the plow of the stair shoe or subrail between balusters; sometimes “neck” moulding.

FIREPROOF CONSTRUCTION – construction designed to withstand a complete burnout of the contents for which the structure was intended without impairment of structural integrity.

FIRE-RATED DOORS – a door which has been constructed in such a manner that when installed in an assembly and tested it will pass ASTM E-152 “Fire Test of Door Assemblies” and can be rated as resisting fire for 20 minutes (1/3 hour), 30 minutes (1/2 hour), 45 minutes (3/4 hour) (C), 1 hour (B), or 1-1/2 hours (B). The door must be tested and carry an identifying label from a qualified testing and inspection agency.

FIRE RETARDANT TREATMENT – impregnation of wood by fire-retardant chemicals to increase its fire resistance by (1) retarding the normal increase in temperature under fire conditions, (2) decreasing the rate of flame spread, (3) lessening the rate of flame penetration, and (4) making fires more easy to extinguish.

FIREWALL – a wall with qualities of fire resistance and structural stability which subdivides a building into fire areas and which resists the spread of fire.

FIVE-PLY CONSTRUCTION – a cross-banded assembly consisting of a core, crossbands and face veneers.

FLASHING – a metal or plastic strip used to prevent water and air leakage between the window or door frame and the surrounding wall; it is attached to the outside face of the head jamb and side jambs.

FLOOR GUIDE PLATE – hardware applied to the floor of the structure to guide bypass, folding and pocket-type sliding doors.

FLUSH DOOR – a door consisting of a core, crossbanding and flat face veneers or a core and flat face veneers only.

Hollow-core Flush Door – a flush door with a core assembly of strips or other units of wood, wood derivative or insulation board which supports the outer faces and with intervening hollow cells or spaces.

Solid-core Flush Door – a flush door consisting of a core of solid wood blocks or strips with crossbanding and face veneers or face veneers only.

FLUTE – a long, rounded groove machined along the grain of a wood member, e.g., a pilaster; may be “through fluted” or “stop fluted”; shallow or deep concave or groove cut-back of surface; repeated flutes produce texture.

FOLDING DOOR – one of two or more sliding doors hinged to move laterally in an opening; “accordion type” door; may be used for a folding partition; a complete unit for folding doors may be obtained consisting of doors with butts applied, track and guide hardware, door pulls, and door frame (optional). A two- or four-door unit is usually called a bifold door.

FRAME – parts which enclose the window or door sash; they are attached to the wood members lining the rough opening. (Usage – vertical frame members are called “side jambs”; the top, horizontal piece is the “head jamb”; the bottom, horizontal piece is the “sill”).

FRANKING – fitting or joining muntins to bars.

FRENCH DOOR – a door with rectangular panes extending its full length – also called “garden door.”

FRIEZE – derived from French “frise” border; a box cornice wood member surfaced four sides nailed to the wall of the structure where the soffit (plancier) and building wall meet; the part of an entablature between architrave and the cornice; the space between the top of the lintel and/or ceiling joists and the bottom of the plate.

FULL BOUND – sash having stiles and rails of same width; “same rail all around.”


GAIN – similar to “dado”; also a notch or mortise made to receive a door butt or strike.

GEORGIAN – the style in architecture, interior design, and decorative arts in Britain and its colonies between 1714 and 1830. Classical forms and motifs dominate, but the style also encompasses Renaissance and Rococo forms as well as a range of Neoclassical styles.

GLASS – a transparent, translucent or opaque material formed by fusing silicates with soda or potash, lime and sometimes various metallic oxides.

Corrugated Glass – glass rolled to produce a corrugated contour; when wired, it is used especially for skylights, roofs and sidewalls; may be plain or wired.

Figured Glass – rolled glass having a patterned or figured surface(s).

Heat-absorbing Glass – glass which intercepts appreciable portions of radiant energy, especially solar energy; obtainable as polished plate, window or other types of glass; color varies among different glass manufacturers.

Insulating Glass – two or more (generally two) pieces, lights or panes of glass separated by a hermetically sealed air space 3/16 to 1/2 inch in width.

Laminated Glass – two or more layers of glass, usually plate, with inner layers of tough transparent plastic, bonded tightly together with the aid of heat and pressure.

Leaded Glass – small, usually irregular panes of glass, sometimes vari-colored, joined together by lead or zinc muntins and bars and used primarily for decorative purposes.

Plate Glass – glass from which surface irregularities have been removed by grinding and polishing so that the surfaces are approximately plane and parallel; also polished plate glass.

Pressed Figured Glass – glass with a determinate figure pressed on one side; this process makes possible a clear, sharp, even-figured pattern which is not obtainable by other methods.

Processed Glass – glass whose surface(s) has been altered by etching, sandblasting, chipping, grinding, etc., to increase the diffusion.

Rolled Glass – glass having a patterned or irregular surface and which varies in transparency; more or less diffusing, depending on pattern; the surface pattern is formed in the rolling process.
Tempered Glass – plate glass with increased mechanical strength.

Wire Glass – flat, rolled glass having a layer of meshed wire completely imbedded in the sheet; used in commercial applications.

GLAZING – glass or other transparent materials, used for windows; also the act of installing the glass.

Double Glazing – glazing with two panes of glass separated by an air space; double glazing may be accomplished by storm sash (panels) or insulating glass; term sometimes refers to storm sash.

Groove Glazing – glazing in which the glass is inserted into a groove machined on the stiles and rails of the sash; a bedding or glazing compound is placed in the groove prior to inserting the glass.

Putty Glazing – glazing by use of putty; the glass is inserted into the putty rabbet, glazier’s points driven and the putty or glazing compound applied to the putty rabbet.

Triple Glazing – glazing with three panes of glass with an air space between each pane.

Wood-stop Glazing – glazing whereby a thin layer of putty or glazing compound is placed in the putty or glass rabbet, the glass pressed into the “bed” and secured by wood stops.

GLAZING BEAD – a strip surrounding the edge of the glass in a window or door; applied to the sash on the outside, the glazing bead holds the glass in place.

GLAZING COMPOUND – a plastic substance of such consistency that it tends to remain soft and rubbery when used in glazing sash and doors; unlike putty, it resists hardening, cracking and eventually failure; sometimes refers to “putty.”

GLUE BLOCK – a wood block, triangular or rectangular in shape, which is glued and nailed into place to reinforce a right-angled butt joint; sometimes used at the intersection of the tread and riser in a stair.

GOOSENECK – a stair crook-shaped in the profile of a goose’s neck; composed of a long curved vertical section of stair rail with a short horizontal section at the top; used at the point of “winders” in an open stairs, at the landing or the head of stairs.

Gooseneck with Landing Return, 1(2) Riser(s) – a gooseneck with the stair rail in the short horizontal section making a 180-degree turn (return) on the level; may be right or left; also gooseneck with level half-turn.

Gooseneck with Level Quarter-turn – a gooseneck with the stair rail in the short horizontal section making a 90-degree turn on the level (on a horizontal plane); may be termed right or left.

Gooseneck with (without) Newel Cap – a gooseneck with (without) a newel cap and no stair rail outlet therefrom in the short horizontal section of the stair crook; a “gooseneck without newel cap” is synonymous with the term “gooseneck”; adaptable for use with either one or two risers.

Gooseneck with Newel Cap and Easing – a gooseneck with the stair rail in the short horizontal section ending in a newel cap and with an easing leading out of the newel cap at right angles to the stair rail; either right or left.

Gooseneck with Newel Cap and Level Outlet Right (Left) – a gooseneck with a newel cap and a rail outlet in the short horizontal section of the stair crook; the rail outlet is at 90 degrees to the newel cap and on level (in horizontal plane); stair crook is termed right or left.

Gooseneck with Newel Cap and Level Outlet Straight – a gooseneck with a newel cap and a rail outlet in the short horizontal section of the stair crook; the rail outlet is opposite its entry into the newel cap.

Gooseneck with Quarter-turn and Easement – a gooseneck with the stair rail in the short horizontal section of the stair crook making a quarter-turn on level and then curving upward (easement) either right or left.

GOTHIC HEAD – an entrance or door head in the form of a pointed arch.

GREEN – a subset of sustainability, the focus of which is life cycle environmental impacts of materials, i.e., “reduce, recycle, reuse.”

GREEN BUILDING PROGRAM – a green building program is a law or regulation that mandates or offers incentives for the construction of green buildings within a community. It can focus on public, residential, and/or commercial buildings.

GRILLE – an ornamental item that visually divides a piece of glass into separate panes; snapped into the window or door sash from the inside, the grille replaces muntins and bars.

GUIDE, DOOR – hardware installed on the floor directly under the head jamb of a sliding door frame to keep the door from swinging out (tilting) of its plane of action.


HAND – a term describing the swinging direction of a door as one stands on the side of the door from which security is desired, namely the outside.

Left Hand – door butts or hinges on left side of person with door swinging away from him.

Left Hand Reverse – same as left hand except door swings towards person.

Right Hand – door butts or hinges on right side of person with door swinging away from him.

Right Hand Reverse – same as right hand except door swings towards person.

HARDWOOD – one of the botanical groups of trees that has broad leaves in contrast to the needle-like leaves of the conifers or softwoods; hardwoods are (1) deciduous (shed their leaves in the fall or at end of each growing season), (2) have shorter-length wood fibers than softwoods, (3) contain cells (vessels) of relatively large diameters (in addition to the wood fibers) and (4) have seeds enclosed by an ovary.

HEADBOARD – a flat board cut to fit the contour of a bow or bay window; it is installed between the window frame and the surrounding wall surface, to create a kind of ceiling.

HEADER – a horizontal structural member (also “lintel”) that supports the load over an opening, such as a window or door.

HEAT LOSS – the Heat Transmission Coefficient (“U” Value) multiplied by the area of the door or window opening or other member of a structure.

HEAT TRANSMISSION COEFFICIENT – hourly rate of heat transfer for one square foot of surface when there is a temperature difference of one degree F of the air on the two sides of the surface; also known as “U” value.

HEEL (of a door) – the “hinge” edge of a door.

HOLLOW-BACK – to groove or remove a portion of the wood on the unexposed face of a wood member to more properly fit any irregularity in bearing surface; conserves on transportation charges, assists in prevention of warping and allows a moulding more or less warped to hug the jamb and plaster more closely; also “backed out.”

HOPPER – an upside-down awning window, hinged at the bottom and opening inward from the top; many basement windows are this type. Also, frequently referred to as a ranch-type window.

HORN – the extension of a stile, jamb or sill.

Double Horn – horn at both ends.

Jamb Horn – the extension of a window frame side jamb beyond the sill and head jamb.

Sill Horn – the extension of the “lip” of a window sill to the outside edge of the casing, brick moulding or sometimes wide blind stop or blind stop extension; the extension of a door sill beyond the frame; sometimes “lugs.”

Stile Horn – the extension of the stile of a panel door beyond the top and bottom rail; “stile lug” or “stile extension.”

HOUSED – the “notching” or “grooving” of one member to receive another.


INCOMBUSTIBLE CONSTRUCTION (Non-combustible) – construction consisting of all structural elements of incombustible materials with fire-resistance ratings of one hour or less.

INFILTRATION HEAT LOSS – heat loss due to air infiltration through cracks and other spaces around windows and doors; crack perimeter multiplied by infiltration factor (cubic feet of air per foot of crack) and the temperature differential between outside and inside surfaces gives the number of BTU’s lost to heat up infiltrated air; see TOTAL HEAT LOSS.

INNER FRAME (Insert Frame) – on a panel door, the intermediate panel member between the stile and door panel which accentuates the sticking of the door.


JACK STUD – vertical wood member at each side of the rough opening for a window or door; the jack stud supports the header.

JALOUSIE – a series of small horizontal overlapping glass slats, sections, jalousies or louvers held together by an end metal frame attached to the faces of window frame side jambs or door stiles and rails; the slats or louvers move simultaneously like a Venetian blind in an outward direction; a louvered window or door; admits air and light but excludes rain and sun; glass storm panels and screen inserts are available.

JAMB – the top and two sides of a door or window frame which contact the door or sash; top jamb and side jambs.

Back Jamb – the side jamb of a box (pocket and pulley type) window frame for a masonry wall which is next to the rough opening; also called “back lining.”

Face of Jamb – the exposed surface of a jamb next to the door or sash.

Split Jamb – a split jamb to enable a pocket-type sliding door or a vertical sliding sash to enter the partition.

JAMB BLOCK – a concrete or cinder block used when window units are installed in a concrete or cinder-block masonry wall; two types of jamb backs, “slotted” (with a 3/4″ slot in the middle on one end of the block) or with a 2″ wide, 4″ deep cut on one end of an 8″ block.

JOINT – the joining of two pieces of wood by nails, glue, adhesives or other means; may be joined end to end, edge to edge, end to edge or end to face; also glue or wood joint.

Blind Mortise-and-tenon Joint – a joint in which the tenon does not extend through the mortise and does not remain visible once the joint is completed; also “blind tenoned.”

Butt Joint – a joint formed by square edge surfaces (ends, edges, faces) coming together; end butt joint, edge butt joint.

Coped Joint – a joint at the meeting of moulded member.

Dado Joint – a rectangular groove across the grain of a wood member into which the end of the joining member is inserted; also housed joint.

Dovetail Joint – a joint formed by inserting a projecting wedge-shaped member (dovetail tenon) into a correspondingly shaped cut-out member (dovetail mortise).

Dowelled Joint – a joint using “dowels”; also “dowelled edge joint.”

Edge Joint – a joint formed by joining together the edges of wood members; the edges may be square edge (plain edge joint) or machined (tongue and groove, dowelled); also “rubbed” joint.

End Joint – a joint formed by the ends of wood members; the more common end joint is the “finger-joint.”

Finger Joint – a series of fingers machined on the ends of two pieced to be joined, which mesh together and are held firmly in position by a water-resistant adhesive.

Haunched Mortise-and-tenon Joint – a joint which the tenon is not the same width as its wood member.

Lap Joint – a joint formed by extending (lapping) the joining part of one member over the joining part of the other member; also “shiplap”, “shouldered rabbet” or “plain rabbet” joint.
Locked-miter Joint – a miter joint employing a tongue and groove working to further strengthen the joint.

Lock Sill Joint – formed by dadoing the side jamb and sill of a window frame.

Miter Joint – the joining of two members at an angle that bisects the angle of junction; also “mitre.”

Mortise-and-tenon Joint – a joint formed by the tenon of one member being inserted into the mortise of the other member; the tenon may be secured in the joint by means of steel pins or nails.

Open Mortise-and-tenon Joint – a joint in which the inserted tenon extends completely through the mortise and the end of the tenon remains visible once the joint is completed; also through or full mortise-and-tenon.

Rabbet Joint – a joint formed by the rabbet(s) on one or both member; also rabbeted edge joint.

Right-angle Joint – a 90-degree joint formed by end to face, edge to face or edge to end of wood members; the joint may be formed with the grain, at right angles or parallel to it.

Scarf Joint – an end joint formed by having the two ends of the members beveled to form sloping plane surfaces.

Slotted Mortise-and-tenon Joint – a mortise-and-tenon right-angle joint in which the tenon is visible on two edges once the joint is completed; also “bridle” or “slip” joint.

Spline Joint – a joint formed by the use of a spline; also “slip tongue” joint.

Tongue-and-groove Joint – a joint formed by the insertion of the “tongue” of one wood member into the “groove” of the other; modifications include tongue-and-groove rabbet joint, dado tongue and rabbet, tongued shoulder joint, dado and rabbet joint, dado and lip joint.

“V” Joint – a joint formed by two adjacent boards in the same plane which have faces with chamfered edges; the wood joint may be center-matched, butt joint or other working.

Wedged Mortise-and-tenon Joint – similar to the mortise-and-tenon joint except that two saw cuts are made in the tenon and fitted with wedges; since the sides of the mortise are flared the tenon cannot pull out after the wedges have been driven and glued into place.

JOIST TRIMMER – a joist doubled or tripled, to support a header and form part of the opening for a stairway or fireplace.


KEYSTONE – the top wedge-shaped voussoir in an arch or vault.

KICKPLATE – a thin polished metal plate applied to the bottom rail or bottom of a door to prevent denting and soiling of the wood surface caused by the kicking action of persons in opening the door; kickplates may be applied to both sides of door.

KITCHEN CABINET – case or box-like assembly consisting of doors, drawers and shelves primarily used for storage for food, utensils, linen, cleaning devices and the like.

Base Corner Cabinet – a base cabinet which makes use of corner space at the intersection of two lines of cabinets.

Base End Kitchen Shelf Unit – semicircular shelves employed on the end of base cabinets.

Base Kitchen Cabinet – cabinet resting on the floor and providing storage and counter space, access to which is provided by doors and/or drawers.

Built-in Kitchen Cabinet – soffit-high cabinet to accommodate oven or refrigerator.

Custom-built Kitchen Cabinet – a term generally applied to a cabinet which is constructed on the job site from material which was not prefabricated or manufactured in a factory; also cabinets not considered to be available from any existing inventory.

Drawer-unit Base Kitchen Cabinet – a base cabinet consisting entirely of drawers.

Factory-built Kitchen Cabinet – a cabinet manufactured in a factory available (1)knocked down, (2) semi-assembled, (3) assembled and not finished or (4) assembled and finished.

Island Base Kitchen Cabinet – a base cabinet entirely removed from any row of kitchen cabinets; two cabinet ends are exposed.

Peninsula Base Kitchen Cabinet – a base cabinet which extends outward at right angles from a row of base cabinets and presents one exposed end.

Utility Kitchen Cabinet – a relatively tall cabinet extending from floor to soffit or ceiling, to provide storage for brooms, sweepers, mops, clothes, etc.

Wall-corner Kitchen Cabinet – a wall cabinet to “turn a corner.”

Wall-end Kitchen Shelf Unit – semi-circular or quarter-round shelves with a standard for attachment to a wall cabinet.

Wall Kitchen Cabinet – a kitchen cabinet attached to wall or suspended from ceiling for providing kitchen storage.

KITCHEN WORK CENTER – one of the three principal work areas in which a kitchen is organized: “work centers” are (1) food storage, (2) food preparation, (3) range.

KNEE SPACE – an outward extension of the upper part of a base kitchen cabinet, directly under the counter and above the cabinet door, to accommodate the knee while working close to the counter.

KNEE WALL MOULDING – a crown-like moulding suitable for installation at oblique joints.

KNOB LATCH SET – door hardware for keeping a door closed and with a spring-operated latch bolt activated by a knob; also passage set.


LAMBS TONGUE – a moulding, of considerable projection as compared to its width, of two opposed ogees separated by a fillet.

LAMINATED – layers of veneer or lumber bonded with an adhesive so that the grain of all layers is essentially parallel; contrasted to plywood, in which the adjacent layers are usually at right angles to one another.

LAZY SUSAN – a circular revolving cabinet shelf employed in corner kitchen cabinet units.

LEVEL HALF-TURN – a stair crook; stair rail with a 180-degree turn on the level (in a horizontal plane).

LEVEL QUARTER-TURN – a stair crook; stair rail with a 90-degree turn on the level (in a horizontal plane).

LIFE CYCLE ANALYSIS – an analysis that examines total environmental impact and business cost/benefit assessment through each stage of a product’s existence, from raw materials acquisition through manufacturing, packaging, shipping, installation, IAQ, and performance, as well as end-of-use resource recovery.

LIGHT (LITE) – a framed opening in a sash or door containing a pane of glass (glass panel); light opening, lite; divided-light; cut-up.
Horizontal Light – a light formed by a horizontal bar extending from stile to stile of a sash or door.

Marginal Light – a light so formed by bars and muntins in a sash or door that unequal light results.

Sidelight – an assembly of stiles and rails, with or without a wood panel, containing a single row of glass panels or lights and installed on one or both sides of an exterior or frame, especially a front entrance door frame; provides light, especially for an entry hall, as well as decorative appeal.

Vertical Light – a light formed by a vertical bar extending from rail to rail of a sash or door.

LINEAL FOOT – having length only; used in designating quantities of mouldings; “lineal” foot usually designates nonspecified lengths.

LINER – most commonly a jamb or sill extension member.

Jamb Liner – a small strip of wood, either surfaced four sides or tongued on one edge, which, when applied to the inside edge of a window jamb, increases its width.

LIP – a rabbet run on the edges of a cabinet door or drawer causing it to project in a closed position beyond the face or surface of the cabinet; a rounded overhanging edge.

LOCK – hardware which keeps windows or doors shut. (Usage – Locks for swinging windows have a “keeper”, a protruding, hook-shaped piece attached to inside face of the stile; sliding windows have “latches”, two-piece units attached to adjoining rails).

LOCK BLOCK – a solid or glued-up block of wood, the thickness of the hollow-core flush door stile, which is joined to the inside edge of the stile and to which the lock is fitted; flush doors have a lock block on each stile.

LOCK RAIL – a horizontal piece of a window between the upper and lower sashes into which the lock is fastened.

LOUVER – an opening of various shapes with a series of horizontal slats so arranged as to permit ventilation but exclude rain, sunlight or vision; may be square, rectangular, triangular, quarter-or half-circle; horizontal slats may be stationary or movable (rolling).

LOW-EMISSIVITY GLASS – glass which restricts the passage of radiant heat, in and out; a metal and metal oxide coating is either suspended between the two layers of glass, or affixed to one of the panes, separated by a small air space.

LUG – an extension of the stiles beyond the meeting rails of a sash, usually ogee-shaped; usually sawn ornamentally on the inside of the stile; “ogee lug”; sometimes the interior door side jamb extension beyond the dado is termed the “lug”; also “joggles.”


MANTLE – the facing of wood, stone, marble, brick or similar material around a fireplace and which usually includes a projecting slab or shelf above it; mantel piece.

MANTEL FACE – horizontal member directly under the mantel shelf; also fascia or frieze of the mantel.

MANTEL SHELF – upper part of a mantel projecting into the room.

MILLWORK – a term to describe those products which are primarily manufactured from lumber in a planing mill or woodworking plant; includes mouldings, door frames and entrances, blinds and shutters, sash and window units, doors, stairwork, kitchen cabinets, mantels, china or corner cabinets and porch work; woodwork.

MIRROR MOULDING – a moulding applied to the surface of a door to provide a frame for and to secure the mirror; may be “one member” (forms a base or frame as well as secures the mirror) or “two member” (consists of a base member applied to the surface of the door and a second member or bead to secure the mirror) mouldings.

MORTISE – a notch or slot cut into a member to receive a projecting part (tenon) of another member to form a “mortise-and-tenon” joint.

MOULDED – worked into a form or shape and referring to wood member other than those “surfaced four sides”; also “stuck.”

MOULDING – a relatively narrow strip of wood, usually shaped to a curved profile throughout its length; used to accent and emphasize the ornamentation of a structure and to conceal surface or angle joints.

Flush Moulding – a moulding on the same level or plane as the wood member or assembly to which it is applied; a member is flush with another when they form an unbroken or even surface; in contrast to “raised” or “recessed” moulding.

Raised Moulding – an applied moulding which partly covers or extends above the face or surface of an assembly.

MULLION – the upright or vertical member dividing the panels in a door; the vertical member of a sash, window or door frame between openings in a multiple-opening frame; the mullion is known as the “mullion center”; frames are termed “mullions”, “triples”, or “quadruples”, depending on whether they have one, two or three mullions respectively; in doors, sometimes “muntings.”

MULTIPLE-OPENING FRAME – a window or door frame consisting of at least one mullion.

MUNTIN – a short “bar”, horizontal or vertical, extending from a bar to a stile, rail or another bar.


NEWEL – the main post at the start of a stairs and the stiffening post at the landing; a stair newel.

Landing Newel – a newel installed on a landing or at the turn of a set of stairs; intermediate newel; “angle newel.”

Starting Newel – the newel installed at the beginning of the flight of stairs; newel post.

NEWEL CAP – a turned decorative cap or top into which the dowel or pin of the newel top fits.

NEWEL COLLAR – a turned wood collar used in lengthening the base of certain stair newels.

NOSED – the rounded edge of a wood member.

NOSING – in stairwork, the rounded edge of the stair tread which projects beyond the face of the riser; “tread nosing”; also applied to the rounded edge of a wood member.

Return Nosing – the nosing of an open stair tread that continues around to the open end(s) of the stairs; the return nosing is applied to the open end(s) of the stair tread and mitred to the nosing of the tread.

Sill Nosing – the nosing of a “main sill and nosing” of a window frame.

NOSING MOULDING – a moulding consisting of a profile that is ”nose and cove” and which is sometimes used on the exposed edges of flooring (especially porch work) to give a rounded or “returned nosing” effect; also “nose and cove.”


OFFSET CENTER OF STAIR CONVERGENCE – a method of “winder” construction whereby the risers do not converge at a point at the turn of the stairs, and afford some width to the winders.

OPENING – a discontinuity in an exterior or interior wall to admit a door or window.

Outside Opening – the measurement from outside of a millwork assembly.

Rough Opening – the opening formed by the framing members; buck opening.

OPERATOR – crank-type hardware for opening a window which swings outward; a jointed, metal arm keeps the window open at any position.

ORDERS – a unique style of column and entablature, in classic architecture, each having standardized details and proportions. The five Orders are Tuscan, Doric, Ionic, Corinthian, and Composite.

OVERHEAD BALANCE – a steel tape which coils up into a metal case installed in the head jamb of a window frame; the end of the tape attaches to each sash, providing activation or balancing; “overhead balance” when installation is in head jamb; patent balance.

OVERHEAD TRACK – metal or wood tracks for sliding doors or sash.

OVERMANTEL – wall paneling with moulded plaster-like decoration installed above the mantel shelf.

OVOLO – a convex profile; usually a quarter-section of a circle and similar to the profile of “quarter-round.”


PALLADIAN – a generic term for classical architecture during the 17th and 18th centuries and widely adapted in England following the publication of the designs of the Italian architect, Andrea Palladio (16th century); Palladian window.

PANEL – a wood surface within a surrounding frame; all panels have structural frames, the interstices of which are filled with sheets or fields called “panels”; the frame is necessary for adequate strength only with the panels occupying considerable more area than the frame; the panel may be raised above or recessed below the surrounding frame and set off from it by moulding or other decorative treatment; “panel” also refers to a sheet of plywood or thin lumber as well as to a section of a floor, wall, ceiling or roof prefabricated of a large size and handled as a single unit in the operations of assembly and erection.

PANEL DIVIDER – a moulding which separates two vertical wood panels along their common edges.

PANEL MOULDING – a decorative moulding used in panel work.

PARTICLEBOARD – a formed panel, consisting of particles of wood flakes, shavings, slivers, etc., bonded together with a synthetic resin or other added binder; the particles are classified by size, dried to a uniform moisture content, mixed with binder, mat-formed, compressed to density and then cured under controlled heat and pressure.

PASSIVE SOLAR HEAT GAIN – solar heat that passes through a material and is captured naturally, not by mechanical means.

PEAKED HEAD – similar to “pediment”; also applies to a door head; peaked cap.

PEDIMENT – a low-pitched triangular entrance head or cap; triangle formed by sloping roof and horizontal cornice; also may apply to window and door openings.

Broken Pediment – a pediment broken along its perimeter; not solid; often contains an urn in its broken portion; may be scroll-like (swan’s neck).

Rounded Pediment – arc-like as contrasted to triangular; accepted, in practice, but does not satisfy definition of “pediment.”

Solid Pediment – a triangular head unbroken along its perimeter; peaked cap.

P.G. – a solid mould consisting of a long bevel with a small fillet on each side.

PICTURE FRAME MOULDING – rabbeted moulding forming a frame for pictures; also the trimming of window units by the use of casing on four sides, resulting in the deleting of stool and apron.

PICTURE MOULDING – a narrow moulding along the perimeter of the walls near the ceiling line to support hooks for picture hanging.

PILASTER – a rectangular, circular or semi-circular member used as a simulated column in entrances and other door openings and fireplace mantels; usually contains base, shaft and capital.

Plain Pilaster – a pilaster surfaced or dressed four sides.

Reversible Pilaster – a pilaster plain on one face and reeded, fluted or otherwise worked on the reverse.

PILASTER CAP – a “plinth-like block” used at the top of a pilaster.

PLANCIER – also “plancher”, “plancer”, “planceer” and “plancia”; see SOFFIT.

PLANTED MOULDING – a moulding applied to a surface which projects or remains above it; “raised moulding”; as opposed to “solid-sticking”; “applied moulding.”

PLASTER BASE – a wood member surfaced three sides, bevelled on the fourth and used as both a base plaster ground and a finish base.

PLINTH BLOCK – a square block at the base of a pilaster; a block of wood placed at the bottom of side door casing to terminate the casing as well as the base; since the door casings and bases are moulded, “plinth blocks” offer a sturdier member and a better appearance; “plinth blocks” are thicker and wider than the abutting members; also base block, foot block or pilaster base.

PLOW – a rectangular groove or slot of three surfaces cut parallel or with the grain of a wood member; in contrast to “dado”, which is cut across the grain.

PLOWED AND BORED SASH – a “box window frame” sash where the edges of the stiles are “plowed and bored” to receive the sash weight cord to tie the knot.

PLUMB – exactly perpendicular or vertical; at right angles to the horizon or floor.

PLY – veneer which has been assembled into a panel; a layer of veneer.

PLYWOOD – a crossbanded assembly of layers of veneer or veneer in combination with a lumber core or plies joined with an adhesive; the grain of the adjoining veneer or plies is approximately at right angles; an odd number of plies is generally used.

POCKET – a removable section of a pulley stile (side jamb) of a box window frame (pocket and pulley) which gives access to the weight box; the standard width is roughly 2″ to 2-1/2″ with the height determined by the length of the sash weight; the lower end of the pocket is located about 6″ above the window sill and may extend midway to the meeting rail; also weight access pocket, weight pocket.

PREFINISHED – millwork with an applied finish coating.

PREFITTING – trimming of the door for width and/or width and height.

PREHUNG DOOR UNIT – a precut and assembled unit consisting of a wood door with preparation for lock hardware that is hung on hinges in a wood frame; the wood frame includes the one-or two-piece jamb adjustable or as-ordered width as well as the door stop moulding and casings (trim); also hinged interior wood door unit; door units other than conventionally hinged are also available.

PRESERVATIVE – any substance that, for a reasonable length of time, will prevent the development and action of wood-destroying fungi, borers of various kinds and other harmful insects that deteriorate wood after the wood has been properly treated with it; also wood preservative.

PRIME COAT – the first coat of paint in an application that consists of two or more coats; also refers to the paint used for such an initial coat.

PUTTY – a precipitated whiting (chalk or calcium carbonate) ground in linseed oil with approximately 5 percent white lead added.


QUARTER-ROUND WINDOW – stationary or operating window with glass shaped as a quarter-circle; it is divided into separate panes or comes with a removable grille, installed on the interior.


R-VALUE – an industry measurement of the resistance to heat flow through a given material. (Usage – the higher the R-Value, the greater the resistance to heat flow).

RABBET – a rectangular cut consisting of two surfaces cut on edge of a member parallel with the grain; a rabbet has two surfaces and a “plow” (three; also “rebate”, rabbit).

RABBETED TO (IN) PAIRS – a pair of sash or doors with rabbeted meeting stiles to prevent swinging through; each sash or door has its meeting stile rabbeted on an opposite edge or corner.

RADIATION – energy released in the form of waves or particles, due to a change in temperature within a gas or vacuum.

RADIUS MOULDING – a moulding run to a specified radius.

RAIL – horizontal member of a window or door sash.

Bottom Rail – the bottom rail of a sash, door, blind or other panel assembly.

Center Rail – a rail, approximately at the mid length point of the frame of a hollow-core door.

Check Rails – meeting rails sufficiently thicker than the window to fill the opening between the top and bottom sash (two adjacent sash on a horizontal sliding window) made by the parting stop of the frame; check rails are usually beveled and rabbeted.

Cross Rail – the rail of a door.

Diagonal Rail – a diagonal rail of a crossbuck or sawbuck of a panel or sash door.

Door Rail – the cross or horizontal members of the framework of a door.

Intermediate Rail – the rail of a door located between the top and bottom rails.

Lock Rail – the intermediate rail of a door at lock height.

Meeting Rail – one of the rails of a window that meets when the window is closed; also middle rail; may be used collectively to designate both sash meeting rails.

Oval Bottom Edge – the bottom rail of a screen with an oval bottom edge; contrast to beveled edge.

Plain Rail – a meeting rail the same thickness as the window.

Plain Beveled Sash Rail – the bottom rail of a sash beveled to conform to the slope of the window frame sill and with no other working.

Stair Rail – the moulded wood member of a balustrade that connects the tops of the balusters and serves as a hand support and guard; sometimes “hand rail.”

Top Rail – the top rail of a sash, door, blind or other similar panel assembly.

Wall Rail – a moulded linear wood member secured to the wall of a closed flight of stairs and which serves as hand support.

RAISED MOULDING – a moulding not on the same level or plane as the wood member or assembly to which it is applied; as contrasted to “flush moulding.”

RAKE MOULDING – a moulding applied to the rake or the exposed inclined ends of a gable roof; term is sometimes applied to any moulding installed in a direction other that horizontal or vertical.

RAMP – a stair rail steeper than the normal rake of a stairs.

REED – a semicircular profile similar to a “bead” worked on a wood member; used commonly in pilasters; opposite of “flute”; reeds are occasionally below the surface.

RESIN – any of various solid or semisolid organic substances extruded from various plants or trees or prepared synthetically.

RETURN – continuation in a different direction of a moulding or projection, usually at right angles.

RETURN MANTEL – the measurement from the surface of the interior wall to the masonry face of a fireplace opening.

REVEAL – the margin visible between the window or door sash and the surrounding frame.

RIM SECTION – the frame assembly of a combination door.

RISE – in stairwork, the vertical or perpendicular measurement between the faces of two consecutive treads; also “stair tread rise.”

Total Rise – the vertical or perpendicular measurement from the lower-level finish floor to the finish floor of the landing or upper floor level where the flight ends.

RISER – the vertical stair member between two consecutive stair treads.

ROOF WINDOW – window designed to be installed on a sloping surface (Usage – “stationary roof windows” are non-operating; “venting roof windows” have the sash hinged at the top, swing outward and are operated by manual or automatic equipment.

ROSETTE – a turned (usually circular or oval) decorative wood plaque secured to a plastered wall and abutted by the end of the stair rail.

ROUGH OPENING – an unfinished wall or ceiling opening, where a window or door will be installed. (Usage – rough openings are lined by wood members; the top one is the “header”, the side ones are the “jack studs”, and the bottom one is the “rough sill”; also rough openings in brick walls are know as “masonry openings”).

ROUGH SILL – the horizontal wood member lining the bottom of a rough opening for a window or door.

ROUND – a moulding whose profile is one-quarter, one-half or a full-circle.

Half-Round – a moulding whose cross section is one-half of a circle; also screen moulding, screen bead, flat half-round.

Quarter-Round – a moulding whose cross section is one-quarter of a circle; sometimes “carpet strip.”

ROUND EDGE – the corner of a piece shaped to a radius; generally implies a greater radius than for an “eased edge”; shaped primarily for appearance.

RUN – in stairwork, the horizontal measurement between the faces of two adjacent or consecutive risers; also “stair tread run” or “going”; also “sash run” or “runway.”

Total Run – the horizontal measurement between the face of the first riser and the face of the last riser of a flight of stairs.


SASH – a single assembly of stiles and rails into a frame for holding glass, with or without dividing bars or muntins, to fill a given opening; it may be either “open” or “glazed.”

Awning Sash – a sash the bottom of which swings outward (awning type) or the top of which swings inward (hopper type).

Barn Sash – a sash usually installed in a rough built-on-the-job type of frame for farm, utility and temporary structures, where economy is a prime prerequisite; utility sash.

Basement Sash – an awning-like sash usually consisting of one, two or three vertical lights; sash swings inward from the top (hopper type).

Cabinet Sash – a sash door used in cabinets; also cupboard sash.

Casement Sash – a sash hinged at the stile to swing outward (swing-out) or inward (swing-in); also French sash or window.

Gable Sash – a decorative sash, commonly utilized in the gables of structures; may be one-quarter circle, one-half circle, full circle or octagonal in shape; usually contains divided-lights and may be installed as a sash or as a frame unit; may be vented.

Glazed Sash – a sash in which the glass has been installed.

Hotbed Sash – a sash used in plant cold frames for forcing plants or other greenhouse activities.

Open Sash – a sash in which the glass has not been installed.

Picture Sash – same as stationary or fixed sash; “picture sash or window” usually implies a relatively large size sash.

Prime Sash – the balanced or activated sash of a window unit.

Stationary Sash – a fixed or nonoperative sash; as a view sash or picture window often used in combination with other types of window and sash units; intended primarily for view purposes and to admit light.

Storm Sash – a glazed panel or sash placed on the inside or outside of an existing sash or window as protection against the elements; an insulated air space is formed between the sash or window and the storm sash; also “double glazing”; “storm panels”, “storm windows.”

Transom Sash – a sash installed in a “transom.”

SASH BALANCE – one of several types of mechanical sash-activation devices; primarily these “balances” include coiled springs, spiral springs or other spring-type devices for raising and lowering the sash.

SASH CLEARANCE – difference between the width of window frame guide or runway and the sash thickness.

SASH CORD – a rope to connect the sash with the sash width in a “box window frame.”

SASH CRACK – sash crack thickness is equivalent to one-half the difference between the inside window frame dimension and the outside sash width.


SASH PIN – a steel nail-like pin driven into the joint formed by the sash rail and stile to penetrate the rail tenon; sash pins are also used at each end of at least one bar; pins may be either smooth or barbed; also a pin or bolt capable of being engaged in one or two holes bored in the side sash jamb to maintain position of sash.

SASH PULLEY – a metal or wood pulley installed in the “pulley stile” of a box window frame to accommodate the sash cord or chain; the pulley is generally located approximately 4″ from the face of the head jamb.

SASH RUNWAY – the space between the parting stop and the window stop in which the bottom sash of a double-hung window slides when raised or lowered; also the space between the blind stop and the parting stop in which the top sash of a double-hung window slides when raised or lowered; any space in which a sash slides; also “sash run”.

SASH TRACK – head or sill sash guides.

SASH WEIGHT – solid, usually cast-iron cylindrical weights to balance or activate the sash in a box window frame (pocket-and-pulley type); sash weights are hung either on sash cords or chains and are of different sizes and weights for each sash size.

SCALLOP – a decorative wood member which contains a series of curves or areas of circles sawn or shaped on one of its edges; a scalloped member.

SCOTIA – a deep concave moulding more than one-quarter round in section; reverse of torus; cove moulding.

SCREEN – a frame assembly of stiles and rails with inserted screening; screens may be of two types, “rigid” and “flexible”; a rigid screen is similar to a storm sash with the screening replacing the glass; a flexible screen is similar in operation to a window shade.

Full Screen – a screen which fills the entire window opening of a double hung window.

Half-Screen – a screen which does not fill the entire opening of a double-hung window but only the bottom sash of the window; “sliding half-screens” may cover either the top or bottom sash.

SCREENING – a mesh of fine aluminum, galvanized steel or bronze wire; “insect wire screening”, “wire cloth” or “insect wire”; also “plastic” and “fiberglass.”

Rolled-into-a-groove Screening – the inserting of screening into a flush moulded screen frame by rolling or pressing the screening into a groove worked into the screen frame rabbet; a flush screen moulding is then placed in the rabbet; if plastic screening is used, a “spline” must be inserted into the groove after the plastic screening has been inserted.

Stapled Screening – the application of screening to a “raised moulded screen” frame, stapling the screening to the faces of the stiles and rails, and then covering with a screen moulding.

SCREEN MOULDING – a small moulding of several different patterns to cover screening when it is nailed or stapled to the screen frame; if screen moulding is “flush” with the frame, a “flush moulded screen”; if raised above the frame, a “raised moulded screen.”

SCREEN STOCK – moulding stock generally 1″ x 2″, 1″ x 3″, 5/4″ x 2″, or 5/4″ x 3″ nominal size for use as stiles and rails in screens; screen stock may be surfaced four sides, rabbeted on one edge as in “combination” screen stock or plowed on one edge as in “sliding” screen stock; also shelf cleat, cleat or clear strips.

SCROLL HEAD – the head or cap of an entrance with a scroll-like design.

SCROLL HEAD AND URN – a scroll head with an urn comprising the cap or head of an entrance.

SDL, SIMULATED DIVIDED LIGHT – the effect of making a single piece of glass look as if it is divided into smaller panes. Bars of plastic, wood, or another substance are attached to the interior and exterior of a window with an element placed in between to create the appearance of glass that is separated into small panes.

SEAT BOARD – a flat board cut to fit the contour of a bow or bay window; it is installed between the sills and the surrounding wall surface, to provide a seat or shelf space.

SEGMENT HEAD – an entrance or door head in the form of the arc of a circle.

SETTING BLOCK – a wood block placed in the glass groove or rabbet of the bottom rail of an insulating glass sash to form a base or bed for the glass.

SHADING COEFFICIENT – a ratio established by the American Society of Heating, Refrigerating, and Air Conditioning Engineers, to compare solar heat gain, through a glazing system, to the total solar heat gain (1.0) through a single sheet of clear glass, 1/8 inch thick. (Usage – the lower the shading coefficient, the lower the solar heat gain).

SHELF CLEAT – a moulding commonly used in closets to support the shelves; also shelf strip.

SHINGLE MOULDING – a moulding used on the rake of a structure.

SHIPLAP – lumber whose edges are rabbeted to make a “lap joint.”

SHOE – a moulding installed at the base of various members of a structure.

Base Shoe – a small narrow moulding running around the perimeter of a room where the base meets the finish floor; also “shoe moulding” and floor mould.

Bent Shoe – base shoe moulding curved or on a radius and used on starting stair treads.

Partition Shoe – moulding that is plowed out to receive the bottom of a partition.

Stair Shoe – a stair member which lies on the top of a curbed stringer and into whose groove or plow the balusters are inserted; also “stair subrail” or “shoe rail.”

SHOW THROUGH – irregular surfaces visible on the face of wood flush door.

SHUTTER – a wood assembly of stiles and rails to form a frame which encloses panels used in conjunction with door and window frames; may also consist of vertical boards cleated together (batten-type shutter).

Reversible Shutter – a shutter which resembles a slat-like blind on one side and a panel-like shutter on the reverse side; also “reversible-shutter blind.”

SIDE JAMB – vertical member of the window or door frame.

SIDE-OF-WINDOW TRIM – the mouldings and/or trim necessary to “finish” or “trim” the interior side of a sash or window frame.

SIDING GROOVE – a groove on the underside of a window sill to accommodate the wood siding or facing of the exterior wall of the structure.

SILL – lower, horizontal member of the window or door frame.

Main Sill and Nosing – a narrower exterior extension fastened to the outside face of a main window sill.

Main Sill and Undersill – an upper thinner member of a two-piece window sill resting on top of a thicker lower member (formerly subsill).

Plain Bevel Sill – an exterior door sill which employs a wood or non-wood threshold.

Steel Sash Sill – a sill to receive the bottom lip of a steel sash.

Threshold Sill – a door sill with the threshold worked on it.

Two-piece Sill – “main sill and nosing” and “main sill and undersill.”

SILL LIP – that part of the window sill extending beyond the outside face of the blind stop; if sill includes and offset, that part of the sill beyond it.

SILL OFFSET – the rabbet(s) on the surface of a window sill to accommodate the window sash and the storm sash and/or screens; originally called “weatherings”; when sill contained two weatherings, known as “double-sunk sill.”

SILL TRACK – metal, wood or plastic tracks or grooves which guide the sash in a horizontal-sliding window unit; also “sill sash guides.”

SINK FRONT – a base kitchen cabinet shallow-front assembly that contains a false drawer front directly below the counter and a pair of doors below to complete the assembly.

SIZE – measurement of millwork items and members.

Actual Size – the true or actual dimensions or size as opposed to “nominal size.”

Finished Size – the overall measurement of any wood part including the solid mould or rabbet.

Glass Size – one of the three measurements of a window or sash unit; glass size is measured from stile to stile and from rail to rail inclusive of the muntins and bars and is always in inches; the size of a pane of glass of any sash or door light.

Outside Opening Size – measurement from outside to outside of any give item; unit measurement.

Window Opening Size – the dimensions of the window frame required to accommodate the window, in feet and inches.

Window Rough Opening Size – the size of the rough frame wall opening to receive the window or sash unit; given in feet and inches; also “buck opening.”

SKID BLOCK – a small wood or metal block applied to the bottom edge of a “prefit door” in order to prevent damage.

SKIM – long narrow repair not more than 3/16″ wide.

SKYLIGHT – a window installed in a roof and assuming the same slope.

SLAT – a thin narrow strip of wood used in door and window blinds, doors and transoms; louver.

SLIDING DOOR, POCKET-TYPE – a door which slides horizontally into a wall pocket or slot recessed into the wall of a structure; imparts additional space to a room compared to the conventionally hinged door since no swing space is required.

SNAP-IN GRID – wood or plastic removable divided-lights for sash and windows.

SOFFIT – the underside of box cornice; in kitchens, the lowered ceiling directly above the top of the wall cabinets which seals off cabinet space too high to utilize; known as “drop ceiling”, “furred-down ceiling”, or “furred ceiling”; also plancier.

SOFTWOOD – one of the botanical groups of trees that has persistent needle-like or scale-like leaves; softwoods are evergreen (only three important native species being deciduous), have longer-length fibres than hardwoods, do not contain vessels and have seeds naked; also know as “cone bearers” or “conifers.”

SOLAR ENERGY – thermal radiation from the sun, as measured by short radiation wavelengths. (Usage – the three kinds of solar radiation are ultra-violet, visible, and near-infrared).

SOLAR ORIENTATION – placement of a structure on a building site to obtain the maximum benefits of sunlight.

SOLID MOULDING – non-finger-jointed moulding, solid length.

SOLID-STICKING – a mould or profile worked on the article itself; also “solid-struck.”

SOLID WOOD – non-veneered.

SPACER BLOCK – a thin strip of wood placed on the edges of a prehung door to take up the door clearance while in transit; also spacer wafer.

STACKING – the vertical joining of awning sash units.

STAIR BRACKET – thin decorative wood member nailed to the face of an open stair stringer immediately under the return nosing of each stair tread; “scroll bracket.”

STAIRCASE – same as “stairs”, especially when a balustrade is included.

STAIR CARRIAGE – a rough structural stair member (stringer) which is cut out to receive the treads and risers, stair carriages may or may not be used in stair construction; “stair carriages” are nonexposed structural supporting members of the finished stairs; also “rough stair stringer”, “horse”, or “springing tree.”

STAIR CLEARANCE – measurement from the tip of the tread nosing perpendicular to the overhead rake of the stairs.

STAIR FLIGHT – a series of steps unbroken by a landing that extends from (1) one main floor level to a landing, (2) landing to landing, (3) landing to main floor level or (4) main floor level to main floor level; a stairway may consist of one or more flights.

STAIR HEADROOM – the clear vertical height measured from the nosing of a stair tread to any overhead obstruction.

STAIR LANDING – a level platform between two flights of stairs.

STAIR RAIL BOLT – a metal bolt consisting of a lag at one end and a nut at the other used in joining a fittings to a “stair rail.”

STAIRS – one or more flights of a series of steps leading from one main level of a structure to another.

Basement Stairs – extend from an uninhabitable to an inhabitable level; service stairs.

Closed Riser Stairs – a stair with risers.

Closed Stairs – a stairway entirely “walled in” on both sides; does not contain a balustrade; also “boxed” or “box stairs”; “closed string stairs”.

Closed and Open Stairs – stairs both closed and open in the same flight.

Disappearing Stairs – a sectional-type stair assembly that folds up and recesses into an opening in the ceiling; also folding stairs.

Double “L”-type Stairs – a platform stairway with two intermediate landings, one near the top and one near the bottom with a change of direction of 90 degrees for each landing.

Finish Stairs – extends from one habitable level to another; also main stairs.

Geometric stairs – a stairway without newels, usually including a circular or elliptical stairwell, the handrail continuing in a smooth unbroken line from top to bottom; winding stairs.

“L”-type Stairs – a platform stairway with flights at right angles to each other.

Open Riser Stairs – a stairway without risers.

Open Stairs – a stairway having one or both sides open to a hall or room and containing a balustrade; open stairs are “right” or “left” hand open or “open both side” depending on the location of the open or nonwalled side(s) as one observes the stairs from the bottom level; also “open string stairs.”

Platform Stairs – stairs that include an intermediate landing(s) in going from one main floor level to another; also “dog-legged” or “broken flight” stairs.

Straight-run Stairs – stairs from one main floor level to another without turns or landings; also “straight stairs.”

“U”-type Stairs – platform stairs with an intermediate landing in which the direction of the stairs returns on itself or reverses direction 180 degrees; should flights be relatively close to one another (narrow well hole), a “narrow U” stairs; flights further apart, wide ”U” stairs.

Winding Stairs – scroll or circular stairs containing wall holes which are circular or elliptical; geometric stairs.

STAIR STRINGER – the inclined side of a stairs that supports the treads and risers; also “stair string.”

Closed Stair Stringer – a plain stringer used to conceal the ends of the treads and risers in an open stairs and also known as a “curb stair stringer”; also refers to a housed stringer installed in a closed stairs.

Finish Stair Stringer – the exposed or finished stringer of a stairs as contrasted to the unexposed or “rough stair stringer” or stair carriage.

Housed Stair Stringer – a finish stair stringer which contains horizontal and vertical grooves or routs on the face to receive the treads and risers; also closed or boxed stringer.

Open Stair Stringer – a finish stair stringer (string) which is cut out to receive the treads and risers; an open stair stringer always requires a balustrade; also “cut”, “return string” or “cut and mitred string.”

Plane Stair Stringer – a nonhoused stair stringer surfaced four sides; also solid stair stringer.

STAIR WEDGES – wood wedges glued and driven into the grooves of a housed stair stringer after treads and risers are inserted to assure a tight fit.

STAIRWELL – the rough framed opening which receives the stairs.

STAIRWORK – a general term applying to the building and erection of stairs.

STARTING RAIL DROP – a stair crook which consists of a stair rail with a 90-degree turn (drop) in a vertical plane and which is returned at its end.

STARTING STEP – a separate stair assembly of stair tread, riser, cove and usually base shoe, joined to a flight of stairs at the main lower level; also “curtail step.”

STEPPING – lumber surfaced three sides and “nosed” one edge; it is generally finished 1-1/16″ in thickness by 9-3/8″ or 11-3/8″ in width and may be classified as “lineal stair tread stock.”

STILE – the upright or vertical outside pieces of a sash, door, blind or screen; “style.”

Angle Stile – narrow strips, usually not moulded, to close the space between the front assembly and the wall of a corner china cabinet.

Hanging Stile – a door stile to which the butts or hinges are applied; also hinge stile; also refers to the side jamb of a window or sash to which pulleys, balances or hinges are applied.

Inside Entrance Stile – the vertical entrance member immediately under the pilaster and next to the entrance opening.

Outside Entrance Stile – the vertical entrance member immediately under the pilaster and away from the entrance opening.

Pulley Stile – in a box window frame the side window jamb in which the pulley is installed.

Stile Plate – thin polished metal plate on the face of the door in the vicinity of the lock or passage set to prevent soiling; also “push plate.”

Striking Stile – the door stile containing the lock.

Veneered Door Stile – door stile of lumber core and face veneers; in “five-ply” construction cross banding veneers are also used; as contrasted to “solid stile.”

STOOL – a moulded interior trim member serving as a sash or window frame sill cap; stools may be “beveled-rabbeted” or “rabbeted” to receive the window frame sill or “nonbeveled” or “nonrabbeted”; some nonbeveled or nonrabbeted stools include a tongue to fit in the groove of the window frame sill; also window stool, stool cap.

STOP – a moulding primarily used in window and door trim.

Door Stop – a moulding nailed to the faces of the door frame jambs to prevent the door from swinging through; door stops are sometimes larger in size than window stops although they are usually interchangeable.

Window Stop – a moulding to hold the bottom sash of a double-hung window in place (sometimes called “check stop”); the weatherstripping of the side window jambs has generally taken over this function, although window stops are still gener- ally employed in trimming out windows and sash.

STRADDLE MOULDING – a two-member decorative glass bead-like moulding around the light opening of a flush door.

STRIKE PLATE – a metal piece mortised into or fastened to the face of a door frame side jamb to receive the latch or dead bolt when the door is closed.

STRINGER MOULDING – a moulding, often a wood or window stop, along the top edge of the stringer of a closed stairs; stringer moulding may also be solid-stuck on the stringer.

STRUCTURAL WINDOW WALL PANEL – a window unit framed into a wall panel in a factory as a structural member of the wall.

STUCCO MOULDING – moulding similar to “brick moulding” except for the inclusion of a groove to receive and hold the “stucco”; the groove prevents plaster cracks where the moulding and stucco meet.

SUB-JAMB – a jamb-like member, usually surfaced four sides, which increases or extends the width of the exterior door frame jamb; sub-jambs imply a larger width than “jamb liners”; can also be used with window units; extension jamb.

SUNBURST – a semi-elliptical area, the lower center of which contains a sun-like figure with sun rays radiating therefrom; may consist of a wood panel or glazed sash; sunburst entrance; sometimes fanlight or elliptical head.

SURROUND – applied to a moulding which extends around an opening such as a fireplace and termed mantel moulding or mantel surround.

SUSTAINABILITY – the concept of meeting present needs without compromising the ability of future generations to meet their own needs.

SUSTAINABLE DESIGN – is design that seeks to avoid depletion of energy, water, and raw material resources; prevent environmental degradation caused by facility and infrastructure development over their life cycle; and create environments that are livable, comfortable, and safe and that promote productivity.

SWEEP – a rubber or vinyl strip applied to the bottom of a door to create an effective seal against the sill (threshold).


TDL, TRUE DIVIDED LIGHT – modern term describing the condition of a window sash divided into small panes by muntins (as opposed to SDL, Simulated Divided Light).

TEARDROP – a term given to mouldings with a gradual curved profile.

TENON – a projecting tongue-like part of a wood member to be inserted into a slot (mortise) of another member to form a “mortise-and-tenon joint.”

THREE-PLY CONSTRUCTION – a crossbanded assembly consisting of a lumber core and two face veneers, skins or plies.

THRESHOLD – a wood or aluminum member, bevelled or tapered on each side, and used with exterior or interior door frames; classified as “interior” or “exterior”; also “saddle.”

Interior Threshold – a threshold, symmetrically bevelled, which when installed provides door clearance for carpeting, ceramic tile and other floor coverings.

Exterior Threshold – a threshold non-symmetrically bevelled (the more gradual and longer bevel facing the exterior) which, when secured to the exterior door frame sill and/or finished floor, prevents water from driving under the door.

TOE BOARD – the wood member that forms the vertical face of the “toe space” in a kitchen cabinet.

TOP ROLLER GUIDE – hardware fastened to the top of a sliding door and which contains a roller which guides in the door’s overhead track.

TORUS – a large bead; opposite of scotia; rope-like moulding.

TOTAL HEAT LOSS – the total heat loss from a structure equal to the sum of the heat loss (transmission) and infiltration (air leakage).

TRADITIONAL – styles of architecture used in the early period of this country symbolizing the American heritage in house design.

TRANSOM – a small opening above a door separated by a horizontal member (transom) bar and which usually contains a sash or a louver panel hinged to the transom bar; the “transom bar” or “transom” may act as a door frame head jamb for the door opening and as a sill for the transom or may be built up and separated; “transom” also refers to “transom bar.”

TREAD – the horizontal stepping of a stairs supported by the stringers; also “flyer”; stair tread.

Landing Tread – a partial tread, usually 4″ in width, which forms the “nosing” of a stair landing or main floor level; rabbeted for finish floor thickness, namely 25/32″ or 13/16″; also used around stair wells; also stair nosing.

TRIM – millwork primarily mouldings and/or trim to finish-off window and door openings, fireplaces, walls and other members.

Running Trim – interior or exterior trim ordered in linear or lineal measurement and which extends for runs around the perimeter of a room or structure.

Side of Trim – trim required to finish one side of a door or window opening.

Standing Trim – interior or exterior trim around window and door openings.

TRIMMING-OUT – installing “trim”; sometimes refers to interior finish.

TRUSS – an assembly of framing members so arranged and fastened together as to form a rigid framework for spanning openings, usually long spans; the truss cannot be deformed by the application of an exterior force without deformation of one or more members.

TURNED DROP – usually an acorn-like turned wood ornament used under the overhang of a Colonial-type two-story structure; originally were carved corner posts.


ULTRAVIOLET – type of radiation with wavelengths shorter than those of visible light and longer than those of X-Rays.

UNITED INCHES – the sum in inches of the width plus the height of a sash.

URN – a turned-wood member commonly used in a broken pediment of an entrance.

“U”-VALUE – the overall heat transfer rate through a combination of materials; it is measured by the BTU’s (energy units) per hour per square foot per degree of temperature difference. (Usage – the lower the “U”-value, the lower the heat transfer rate in specified conditions.)


VAPOR BARRIER – generally, a building paper with a low rate of vapor transmission and installed on the warm side of walls.

VENEER – a thin sheet or layer of wood, usually rotary cut, sliced or sawn from a log, bolt or flitch; thickness may vary from 1/100 to 1/4 of an inch; also skin, ply, veneer ply.

VENT – saw kerf run on top and bottom rails of hollow-core flush door to equalize the inside and outside atmospheres of the door.

VERGE BOARD – an exposed member nailed along the rake of a gable-end roof open cornice.

V-GROOVE – a V-shaped groove cut into the surface of a wood member for decorative purposes; V-grooving is often done on the exterior surface or face of solid flush doors; see JOINT.

VOLUTE – a stair fitting consisting of an easement with a spiral section of stair rail, inclusive of a newel cap, extending to the left or right of the easement in a horizontal plane; also volume with easement.


WAINSCOT – a lower interior wall surface (usually 3 to 4 feet above the floor) that contrasts with the wall surface above it; an interior wall composed of two different interior wall surfaces one above the other.

WALL THICKNESS, EXTERIOR – the measurement from the inside face of the interior wall surface to the outside face of the sheathing.

WALL THICKNESS, INTERIOR – the measurement from face to face of the interior wall surfaces.

WATER DRIP – a moulding sometimes used on the exterior surface of the bottom rail of an in-swinging casement sash in order to prevent water from being driven in over the sill; may be installed along bottom rail of the door to direct water away from threshold or sill.

WEATHERING – the mechanical or chemical disintegration and discoloration of the surface of wood caused by exposure to light, the action of dust and sand carried by windows and alternate shrinking and swelling of the surface fibres with continual variation in moisture content due to changes in the weather; also an inclined surface on a member such as a cornice or sill which direct away rainwater.

WEATHERSTRIP – variously shaped metal, vinyl plastic or moulded-fibre strips which fit tightly against sash or door frame parts to prevent air infiltration through cracks.

Adjustable-pressure Weatherstrip – sash or window weatherstripping on which sash tension is maintained by means of spring action.

WEIGHT BOX – in a box window frame (pocket-and-pulley type) the space enclosed by the side jamb, pulley stile, blind stop, inside rough casing (sub casing) and the 2 x 4 doubler (back jamb); contains the sash weights and space for their up and down movement; sometimes “pulley pocket.”

WELL HOLE – the clear floor-to-floor space around which a stairs turns or between handrails.

WINDBREAK – an exterior door frame member, usually surfaced four sides, rabbeted into the unexposed outside corner of the door frame jamb and flush with the sheathing to provide a weathertight seal between the door frame and structure and a nailing surface to secure the frame to the structure; the brick moulding and/or casing conceals the joint made by the windbreak and the jamb; usually deleted from the door frame; also “outside lining” or “liner”; also may apply to sill of window frame (“sill windbreak”).

Reversible Windbreak – a “windbreak” adaptable for either 1/2″ or 25/32″ (3/4″ sheathing).

Sill Windbreak – a window frame member occasionally used to prevent air infiltration around the sill and secure the frame to the structure; generally installed in a groove in the bottom of the window frame sill immediately in back of the sill sliding groove.

WINDER – radiating or wedge-shaped stair tread at the turn of a non-platform-type stairs.

WINDOW – consists of two or more single sash to fill a given opening; may be open or glazed.

Bay Window – one or a series of windows installed in a “bay” or projecting section of a building; a “bay” may be an arc or polygon when a “bay” is or closely approaches an arc, the window is termed a “bow.”

Bow Window – a series of adjoining window units, commonly five in number, installed on a radius; radial bay window.

Check Rail Window – double hung whose meeting rails are of the “check rail” type.

Dormer Window – any window installed in a roof.

Double-hung Window – consists of two sash, top and bottom, which (1) slide vertically past each other, (2) are joined by a meeting rail and (3) are held in any open position by means of weights or one of several types of balancing devices.

Fire Window – sash or window constructed and glazed to give protection against the passage of fire.

French Window – two casement sash each hinged on one stile and opening in the middle; the sash extend down to the floor and serve as a door to a porch or terrace.

Horizontal-sliding Window – consists of two or more sash which slide horizontally past each other; one or more of the sash may be fixed or non operative or all sash may operate; the sash come together and form a vertical-meeting rail (stile) in a closed position.

Oriel Window – a bay window at an upper floor level supported upon corbels or a pier attached to the main wall; found in most houses of importance during 15th and 16th centuries.

Plain Rail Window – a double-hung window whose meeting rails are of the “plain”, non-check rail type; a “plain rail window” frame (1) does not use a parting stop, (2) the bottom rail is usually not beveled, (3) the thickness of the sash is 1-1/8″, (4) the top rail of the bottom sash contains a putty rabbet (none is employed in a “check rail window”) and (5) either sash may be fixed.

Ribbon Window – a relatively long, narrow line or strip of windows or sash such as two or more single awning sash units adjoined horizontally.

Single-hung Window – similar to a double-hung window with the top sash stationary or non operative while the bottom sash operates freely; vertical slider.

Window Clearance – the measurement between the interior and exterior face of the sash and the corresponding parallel surfaces of the window stop and parting strip; the difference between the width of the sash runway and the sash thickness; also “sash clearance”; window face clearance.

Window Crack – the measurement between the edges of the sash and the corresponding parallel surfaces of the jambs or one-half the difference between the inside window frame dimension and the outside width of the sash; also “sash crack” or “crack”; window edge clearance.

WINDOW FRAME – a group of wood parts so machined and assembled as to form an enclosure and support for a window or sash.

Box Window Frame – a window frame in which the sash are activated or balanced by sash weights attached to the end of sash cords or chains which are fastened to the sash, the sash cord or chain carried over a pulley, installed in the side jamb (pulley stile); the sash weights are contained in the weight box; also pocket-and-pulley type.

Split-head – a frame whereby a sash is raised through a split-head jamb; similar to a barn sash installed in a frame.

WINDOW JAMB – the part of the window frame which surrounds and contacts the window or sash that the frame is intended to support.

Head Window Jamb – the horizontal jamb forming the top of the window or sash frame.

Rabbeted Window Jamb – a window jamb with a rabbet on one or both edges to receive a window or sash.

Side Window Jamb – the vertical jamb forming the sides of the window or sash frame.

WINDOW STOOL, NONBEVELED, NONRABBETED – a window stool without a bevel or rabbet and which may or may not contain a tongue or rabbet on its exterior edge; see STOOL.

WINDOW TRIM – the mouldings and/or trim necessary to finish or trim a sash or window frame.

WINDOW UNIT – consists of a combination of the frame, window, weatherstripping, sash-activation device and at option of manufacturer screens and/or storm sash assembled as a complete and properly operating unit.

WOOD ALLOWANCE – the difference between the outside opening and the total glass measurement of a given window or sash.

WOOD FRAME – a group of wood parts so machined and assembled as to form an enclosure and support for a window or door.

WOOD FRAME STRUCTURE – a structure whose structural frame consists primarily of wood members, inclusive of exterior and interior frame walls that support the floors and roof; exterior facing of the wall may be brick, stone, stucco or other non wood material; frame structure.

WOOD FRAME WALL – a wall basically framed or constructed of wood members; wood member usually employed are studs, plates and sheathing; may be faced on the exterior with wood or non-wood facing materials such as brick, stucco, stone; also “frame wall.”

WOODWORK – used interchangeably with Millwork; may apply to anything made of wood.

WREATH – the curved part of the stair stringer in a winding stairs; also refers to a curved portion of the stair rail; curved section of a stair rail curved in both the vertical and horizontal planes (volute).


YOKE – in a box frame window, the head window jamb.