Architectural and Engineering Glossary



Symbol for “hour.”


A steel bar shaped like an H;used in structural systems;one form of main runner in a suspended acoustical ceiling.


A steel beam shaped like an H.


A hollow concrete masonry unit having both ends open in the form of one-half of a cell.


Horizontally perforated brick.


In a ceiling suspension system,a light metal member shaped like the letter H on its side;one side of the H is attached to a channel,and the other (lower) side fits into the kerfs of ceiling tiles.


Same as H-beam.

H/D Ratio

The ratio of the height H,to the diameter D.


 In the lumber industry, abbr. for “hit and miss.”


A barrier in the form of a trench; usually used to prevent livestock from crossing; a sunken fence.

Habit Of Growth

 The distinctive appearance and pattern of growth of a plant.

Habitable Area

The gross floor area of an occupied dwelling, not including the basement, garage, or crawl spaces.

Habitable Room

 A space used for living, sleeping, eating, or cooking, or combinations thereof, but not including bathrooms, closets, halls, stor- age rooms, utility and similar spaces.

Habitable Space

By code, a space occupied by one or more persons for living, sleeping, eating, or cooking (although a kitchenette is not usually deemed to be a habitable space). Compare with nonhabitable space.


 1.A dwelling or habitation. 2.A niche for a statue.


for Historic American Buildings Survey.


 One of a series of parallel lines drawn on topographic maps in the direction of the slopes of hills or depressions to indicate relief features. The steeper the slopes, the heavier and more closely spaced the hachures become.


1.A large estate in North and South American areas once under Spanish influence. 2.The main house on such an estate or ranch.


1.Roughening a surface by  striking  with a tool. 2.Laying brick so that the bottom edge is set in from the plane surface of the wall. 3.In a stone wall, the breaking of one course of stone into courses of different height.

Hackingknife, Hacking-outtool

 Aknifeused to remove old putty from a frame before reglazing. 


A saw having a blade (typically fine toothed) which is supported in an adjustable metal frame; used for cutting metals.

Hafner Ware

 In northern European decorative arts of the Renaissance and derivatives, modeled, lead glazed earthenware often used for tiled heating stoves.


The handle of a tool.


A sacred place; a baptismal font.


Abbr. for “Honorary Member, American Institute of Architects.”


The central chapel of the three forming the sanctuary of a Coptic church.

Hair Beater

A tool formerly used by plasterers to remove hair or fiber from plaster; made of two pieces of wood lath, fastened at one end by wire.

Hair Felt

A non woven felt usually made of cattle hair; once used as thermal insulation in buildings. 

Hair Hook

A tool now obsolete, having several tines for mixing hair or fiber into plaster.

Hair Interceptor

hair trap A device used to remove hair before it enters a drainage system.

Hair Mortar

A mortar (traditionally) containing a mixture of cow’s hair, lime,and sand.

Haired Mortar

Mortar containing hair or fiber.

Hairline Cracking, Hair Cracking, Plastic Shrink Age Cracks

Very fine cracks, in a random pattern,which usually do not completely penetrate a paint film,an exposed layer of concrete, etc. 

Hairline Joint

Between two abutting members,a joint not more than 1⁄64  in. (0.38 mm) wide.


1.The wedge used to tighten some types of form ties.2.A hairpin shaped anchor set in place while concrete is plastic.


In Hawaii,a primitive house, especially one consisting of a wood framework covered by thatched grass.

Half Baluster

An engaged baluster,projecting about half of its diameter.

Half Bat, Half Brick, Snap Header

A brick cut to half its length.

Half Bath

A room containing a wash basin and toilet (W.C.).

Half Cape House

A Cape Cod house that has two double hung windows on only one side of the front door.

Half Column

An engaged column projecting half its diameter,usually slightly more.

Half Door

The lower half of a Dutch door.

Half Dovetail

A wood joint similar to a dovetail but having only one side flared;the other side is straight.

Half Figure

Same as terminal figure.

Half Hatchet

A tool similar to a lath hammer but with a broader blade.

Half Header

A brick,or cement block,either cut longitudinally into two equal parts or cut into four parts by cutting these halves transversely;used to close the work at the end of a course.

Half House

A Cape Cod house or saltbox having two windows on one side of the front door and none on the other.

Half Landing

Same as halfpace.

Half Principal

A roof member or rafter  that does not reach to the ridgepole but is supported at its upper end by a purlin.

Half Round, Half-round Molding

A convex strip or molding of semicircular profile.