Architectural and Engineering Glossary


Auxiliary Rafter

Above a principal rafter,a second principal rafter,occasionally used in a large queenpost truss.

Auxiliary Reinforcement

In a prestressed structural member,any reinforcement in addition to that whose function is prestressing.

Auxiliary Rim Lock

A secondary or extra lock that is surface mounted on a door to provide additional security.

Auxiliary Rope-fastening Device

A device attached to an elevator car,to a counterweight,or to the overhead dead-end rope-hitch support;automatically supports the car or counterweight in case the fastening for the wire rope (cable) fails.

Available Short-circuit Current

The maximum electric current delivered by the electric power system to a fault at a given point in a circuit.

Avalanche Protector

A barrier that prevents loose material from sliding into the tracks or wheels of any type of excavation or digging machine.


That part of a building which projects prominently from the main mass,e.g.,a pavilion.


On drawings,abbr.for “avenue.”


Glass (or glazes) containing colored spangles of nonglassy material.


1.A wide street, usually planted with trees; generally straight.2.A way of approach or access.

Average Frequency Of Occurrence

The average number of years between storms that will produce rainfall rates equaling or exceeding a given amount;sometimes called the “return period.”

Average Bond Stress

The force in a steel reinforcing bar divided by the product of its perimeter and its embedded length.

Average Concrete

Concrete that is made with out artificial aggregates or admixtures;its strength is not established by tests but is assumed to be the value derived from its water-cement ratio.

Average Grade

Within a building construction site,the arithmetic average of the elevations of various ground surfaces within the site.

Average Haul

The average distance that a grading material is moved from cut to fill.

Average-end-area Method

A procedure for calculating the volume of earthwork between two cross sections;the cross-sectional areas are averaged  and  multiplied by the distance between cross sections to determine the volume. 


On drawings,abbr.for “average.”

Avodire, White Mahogany

A west African wood,pale yellow to white in color;soft to hard;light in weight to moderately heavy;frequently ribbon-striped.Used for interior finish,plywood, and paneling.


Abbr. for “actual weight.”


A communication from an owner accepting a bid or negotiated proposal.An award creates legal obligations between the parties.


On drawings,abbr.for American wire gauge.


Abbr.for “Architectural  Woodwork Institute.”


A pointed tool used for piercing holes in thin wood,hardboard, etc.


A roof like covering of canvas,or the like,often adjustable,over a window,door,etc.,to provide protection against the sun,rain,and wind. 

Awning Blind

A blind which is hinged at the top;can swing outward and be fixed in position by a stay.

Awning Window

A window consisting of a number of top-hinged horizontal sashes one above the other,the bottom edges of which  swing outward;operated by one control device.


Abbr.for “American Wood-Preservers’ Association.”


1.Abbr.for “all wood screws.”2.Abbr. for “American Welding Society.”

Axed Arch

An arch which is constructed of bricks that have been roughly cut into a wedge shape. 

Axed Brick,rough Axed Brick

A brick,shaped with an ax,that has not been trimmed;when laid,the joints for such bricks are thicker than those for gauged brick.

Axed Work

(Brit.)A hand dressed stone surface showing toolmarks made by an ax,pick,or bushhammer.


An ax for spalling or dressing rough stone;has either one cutting edge and one hammer face or two cutting edges.

Axial Force

See axial load.

Axial Force Diagram

In statics,a graphical representation of the axial load acting at each section of a structural member,plotted to scale and with proper sign as an ordinate at each point of the member and along a reference line representing the length of the member.

Axial Load, Axial Force

The resultant longitudinal internal component of force which acts perpendicular to the cross section of a structural member and at its centroid,producing uniform stress.


A straight line indicating center of symmetry of a solid or plane figure.

Axle Pulley

See sash pulley.

Axle Steel Reinforcing Bar

A reinforcing bar fabricated from carbon steel axles of railroad cars.

Axminster Carpet

A carpet having pile which is attached to the carpet backing by inserting the tufts by rows between the warp threads and then binding them by means of the filling;this method of carpet construction permits intricate design and almost any number of colors to be used.

Axonometric Projection

A form of orthographic projection in which a rectangular object,projected on a plane,shows three faces.One of two general divisions of pictorial projection (the other being oblique projection);often divided into three types:isometric,dimetric and trimetric.


A type of pillar,placed on a platform attached to a Buddhist stupa.


In plane surveying, a horizontal angle measured clockwise from north meridian to the direction of an object or fixed point.

Azimuth Traverse

A survey traverse in which the direction of the measured course is determined by azimuth and verified by back azimuth;to initiate this type of traverse,it is necessary to have a reference meridian.


1: In Hispanic architecture, a flat roof. 2: An open, elevated terrace, usually located at the back of a house which it adjoins.

Aztec Architecture

The architecture of the Aztecs in Mexico,succeeding the Mayans,from the 14th cent. until the Spanish conquest in the 16th cent.


An earthenware tile of Spanish manufacture,painted and enameled in rich colors, having a metallic luster.