Architectural and Engineering Glossary



The outerworks or wall surrounding and protecting a castle.


A narthex or porch of any description leading into the nave of a church.


 A wooden hanging which was once displayed over, and in front of,the altar of a medieval church.


A seat behind the dais in a choir,reserved for the clergy.


A preliminary portal;an outer gate or door.


A room adjacent to a larger, more important one;frequently used as a waiting area.


Material applied to plants prior to transplanting to reduce the amount of moisture lost from transpiration.

Antimony Oxide

A white opaque pigment used in paints and plastics to provide flame retardant properties.It has better opacity than extenders but is not as good as titanium dioxide.

Antimony Yellow

See Naples yellow.


One of two chapels at the entrance end of a Byzantine church.


A feature that prevents the reclosing of a circuit breaker until the cause of the closing has been corrected.

Antique Crown,eastern Crown

A heraldic device consisting of a headband with an indefinite number of pointed rays projecting  from it.

Antique Glass

A textured cylinder glass of uneven thickness,used primarily in stained glass windows;similar in characteristics to the stained glass of the Middle Ages.


A technique of handling wet paint,by combing,graining,or marbling,so as to expose parts of the undercoat;also called broken color work.

Antiquum Opus

Same as opusincertum.


See in antis.

Antising Lamp

Same as low noise lamp.


An adjective applied to a mechanical device,such as a valve,that eliminates siphonage.

Antisiphon Trap

See deep seal trap.

Antisiphonage Vent

Same as back vent.

Antislip Paint

A paint with a high coefficient of friction,caused by addition of sand,wood flour,or cork dust;used on steps,porches,and walkways to prevent slipping.

Antismudge Ring

A frame attached around the perimeter of a ceiling mounted air diffuser,which minimizes the formation of rings of dirt on the ceiling.

Antistatic Agent

An agent which minimizes static electricity in plastics;may consist of chemical additives or metallic devices connected to an electrical ground.

Antisun Glass

See coated glass and tinted glass.


Abbr.for “access panel.”


Abbr.for “American Plywood Association.”


The columnar audience hall in a Persian palace.


1.A  room or suite of  rooms designed to be lived in,containing at least one bathroom;is separated from,and is usually one of,many similar units within a multiple dwelling.2.A building containing at least three such dwelling units;an apartment house.Also see efficiency apartment,garden apartment,apartment hotel.


A group of rooms used as a dwelling by one person or one family.


On drawings,abbr.for “acoustical plaster ceiling.”


In architecture or construction,the highest point,peak,or tip of any structure.


saddle stone The uppermost stone in a gable,pediment,vault,or dome;usually triangular,often highly decorated.


A room in Greek or Roman baths,or in the palaestra,where the bathers or those taking part in gymnastic exercises,undressed and dressed.


A shed roof having rafters that are let into,or rest upon,a wall.


1.That part of a column where the shaft of the column springs from its base or where the shaft terminates at its capital;usually molded in a concave sweep;also called a scape or congé.2.The hollow (i.e.,scotia) beneath the echinus of some Classical capitals.


Same as apophyge.


A unit of luminance equal to (1/) candela per square meter.


In ancient Greece and Rome,a storeroom of any kind,but for storing wine.

Appliance Lamp

An electric lamp designed for high temperature service.

Appliance Regulator

A regulator for controlling and maintaining a uniform pressure of gas supplied to an appliance.

Application For Payment

The contractor’s written request for payment of amount due for completed portions of the work,1 and, if the contract so provides,for materials delivered and suitably stored pending their incorporation into the work.

Application Life

Same as working life.

Applied Molding

A molding that is nailed on,laid on,or otherwise fastened to a surface,rather than cut into the surface itself.

Applied Trim

Supplementary and separate decorative strips of wood or moldings applied to the face or sides of a frame,as on a doorframe.


1.An accessory decorative feature applied to an object or structure.2.In ornamental work,one material affixed to another.

Approval Drawing

In building construction,one of the drawings furnished by a manufacturer to a purchaser for his approval.Such an approval affirms that the manufacturer has correctly interpreted all contractual requirements.

Approved Ground

A ground (such as the steel framework of a building,a concrete-encased electrode,or a ground ring) that meets the requirements of the National Electrical Code or other applicable code.

Approving Authority

The individual agency,board,department,or official established and authorized by a political subdivision (e.g.,state,province,county,city,or parish) which is created by law to administer and enforce specified requirements.


On drawings,abbr.for “approximate.”


1.Any built-in,nonstructural portion of a building,such as doors,windows,ventilators,electrical equipment,partitions,etc.2.An incidental property right,as a right- of-way.appurtenance 1.Any built-in,nonstructural portion of a building,such as doors,windows,ventilators, electrical equipment,partitions,etc.2.An incidental property right,as a right of way.