Architectural and Engineering Glossary


An entrance or passage.

Adjoining Grade Elevation

The average elevation of the final grade adjoining all exterior walls of a building,calculated from grade elevations taken at intervals (usually 10 ft or 3 m) around the perimeter of the building.

Adjustable Base Anchor

A device used to hold a doorframe above the finished floor.

Adjustable Doorframe

A doorframe which has an adjustable jamb so that it can be installed in walls of different thicknesses.

Adjustable Square, Double Square

A try square the arm of which is at right angles to the handle;the position of the arm may be moved so as to form an L or a T.

Adjustable Wrench

Any one of several types of wrenches having one jaw fixed and the other adjustable;set to the desired size by means of a knurled screw.

Administrative Authority

The individual,official,board,department,or agency established and authorized by a city,county,state,or political subdivision created by law to administer and enforce the provisions of a code.


A material other than water,aggregates,lime,or cement,used as an ingredient of concrete or mortar,and added to the batch immediately before or during its mixing;used as a water repellent,as a coloring agent,as a retarder or accelerator (to modify its setting rate), etc.

Adobe Blasting

Same as mud capping.

Adobe Brick

Large,roughly molded,sundried clay brick,usually of varying sizes.

Adobe Quemado

An adobe brick that has been kiln dried at a temperature lower than that required to produce a hard burnt brick; usually deep red in color,relatively soft, and rough in texture.


A box for mixing adobe and shaping it into bricks.

Adopted Street

In Britain,a dedicated street. 


The action of a material in extracting a substance from the atmosphere (or a mixture of gases and liquids) and gathering it on the surface in a condensed layer;the process is not accompanied by physical or chemical change.


In the Middle Ages in Britain,said of a castle that was crenelated without a license to erect battlements.Such licenses were granted by the reigning monarch in exchange for a cash payment from the castle’s owner.

Advance Slope Grouting

Grouting by a technique in which the front of the mass of grout is forced to move horizontally through preplaced aggregate.

Advance Slope Method

A method of concrete placement in which the face of the fresh concrete moves forward as the concrete is placed;the face of the fresh concrete is not vertical.

Advanced Nursery Stock

A deciduous tree,of specified size,which has been transplanted several times and has had its roots pruned in preparation for its final transplantation.

Adverse Possession

Occupation of  property by one not the true owner,openly,notoriously,and continuously.See statute of limitations; squatter’s right;proscription.

Advertisement Curtain

On the stage of a theater,a curtain which bears advertisements;usually behind the asbestos curtain,but sometimes (rarely) the asbestos itself.

Adytum, Adyton

1.The inner shrine of a temple reserved for the priests.2.The most sacred part of a place of worship.


A cutting tool whose thin arching blade is perpendicular to the handle;used for the rough shaping of wood.

Air Reheater

In a heating system,any device used to add heat to the air circulating in the system.

Air Right

The legal property right for use of the space above a specified elevated plane;usually includes the right to ground support but excludes other rights to ground use,e.g,the right to construct a building over a railroad track.

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.