Architectural and Engineering Glossary


Haul,haul Distance

1.The distance that an excavated material is moved from the cut to the fill.2.The distance along the most practical route for trucks to carry excavated material from its center of mass to the center of mass of the fill.


1.The middle part between the crown and the springing of an arch.2.The part of a beam projecting beneath a roof slab or floor.3.That portion of a pipe barrel extending from the bottom to the springline.4.The lower third of the circumference of a pipe.5.The deepened section of a beam near a support.

Haunch Arch

See hanse arch.

Haunch Board

One of the boards on both sides of a form for a concrete girder.

Haunched Beam

A beam whose cross section thickens toward its supports.

Haunched Mortise-and-tenon Joint

A joint between two members,formed by fitting a haunched tenon at the end of one of the members into a corresponding mortise in the other.

Haunched Tenon

A tenon,part of which has a smaller width than the full width of the wood member on which it is formed.


1.Placing bedding material around the haunch of a pipe. 2.The concrete support at the sides of a drain or sewer pipe above the bedding.

Hautepace, Hautpace

Same as halfpace.


Same as ha-ha.


A flat piece of metal or wood used by plasterers to carry plaster or mortar;held by a wooden handle on the underside.

Hawkbill Snips

Tin snips having a curved jaw which is shaped to facilitate cutting along a curve.


A beak molding. 


Same as ballflower. 

Hay Barrack

An open sided structure for storing an overflow of hay from the main barn; usually had a four- or five-cornered roof that could move up on poles as the hay was packed beneath it.

Hay Hood

Same as hanging gable.


A straw rope.


A lightweight aggregate,used in concrete,having an expanded cellular structure;produced by heating shale.


The upper part of a barn in which hay is stored.

Hazard Assessment

An evaluation of the environmental dangers to which a site may be subject,such as earthquakes,flooding,tornadoes,and hurricanes.

Hazard Of Contents

The relative danger of fire starting and spreading, of smoke or gases being generated,of explosion or other occurrences which potentially endanger the lives and safety of the occupants of a building or structure.

Hazardous Area

1.Within a building,an area which houses highly combustible,highly flammable,or explosive products or materials which are likely to burn with extreme rapidity or which may produce poisonous fumes or gases,including highly toxic or noxious alkalies,acids,or other liquids or chemicals,which involve flame,fume,explosive, poisonous,or irritant hazards.2.Any area in which there are fine particles or dust subject to explosion or spontaneous combustion.

Hazardous Substance

A substance which, by reason of being explosive,flammable,poisonous,corrosive,oxidizing,or otherwise harmful,is likely to cause death or injury.


Dullness of a paint film resulting from formation of very fine surface imperfections.


1.Abbr.for “hollowback.”2.Abbr. for hose bib.


On drawings,abbr.for “hardware.”


Abbr.for hardwood.


1.In general,the top or upper member of any structure;the top or end (esp. the more prominent end) of a piece or member. 2.The upper horizontal cross member, between the jambs,which forms the top of a door or window frame;may provide structural support for construction above if required,as a doorhead or window head.3.A stone that has one end dressed to match the face because the end will be exposed at a corner or in a reveal. 4.A roofing tile of half the usual length but of the same width;for forming the first course at the eaves.5.See static head.

Head Casing

The horizontal casing,1 across the top of a window or door opening.

Head Flashing

The flashing installed in a masonry wall over a window opening or projection.

Head Guard

Cavity flashing over a window or door frame.

Head Jamb, Yoke

The horizontal member forming the top of a door opening;a doorhead. 

Head Joint, Cross Joint

The vertical mortar joint between ends of masonry units.

Head Lining

The lining at the head of a door opening.

Head Loss

Same as pressure drop.

Head Nailing

The nailing of slates through holes near the heads of the slates.

Head Piece

1.The capping piece of a series of upright timbers.2.The uppermost horizontal member of a wood partition.

Head Plate

Same as wall plate.

Head Stop

Same as label stop1.

Head Up

To remove the lower branches from a tree or large shrub.

Headache Ball

See breaker ball.


1.A masonry unit, laid so that its ends are exposed, overlapping two or more adjacent withes of masonry and tying them together; a bondstone; a bonder.2.A header joist.3.A framing member which crosses and supports the ends of joists,rafters,etc.,transferring the weight of the latter to parallel joists, rafters,etc.4.In plumbing, a pipe having many outlets which are parallel and frequently at 90to the center line of the pipe. 5.A chamber into which a number of pipes open. 6.A platform header.7.A transverse raceway for electrical conductors which provides access to a cellular floor,thereby permitting  the convenient installation of electrical conductors.8.The structural member immediately over a door opening.

Header Block

A concrete masonry unit having a portion of one face shell removed to facilitate bonding with adjacent masonry such as brick facings.

Header Bond

A pattern of brickwork consisting entirely of headers,1;usually,each course of headers is displaced by half the width of one header with respect to the headers in the course above and the course below.

Header Course, Heading Course

In masonry,a continuous course of headers.

Header Duct

A main duct or feeder duct for bringing electrical cable from a service closet to distribution ducts.

Header Joist, Header, Lintel, Trimmer Joist

A short structural member (as used in framing  an opening) which is fastened between parallel full-length framing members at right angles to them and supports cut-off members,e.g.,the common joists in framing around a rectangular opening in a wood floor.Also see tail piece.

Header Tile

Tile containing recesses for brick headers in masonry faced walls.


Having the height of a masonry wall to the first header course.


1.Same as upsetting.2.A classification of related data used in the AIA filing system (Part Two of the uniform system) as the first step in subdividing each of the sixteen divisions and corresponding generally to the sections used in Parts One and Three.