Architectural and Engineering Glossary



See sale-and-leaseback.


A tenure by lease;real estate held under a lease.


Abbr.for “light-expanded clay aggregate.” 


A liquid,obtained in refinement of soya beans or cottonseed;used in paints to promote pigment wetting and to control pigment settling and flow properties.


In a church or lecture hall,a stand with a slanting top to hold a book,speech,or music at the proper height for reading.


The site in a Christian church where parts of the Scripture are read.


 Abbr.for light-emitting diode.


1.A small projecting member or molding.2.A wood member across a number of boards to hold them together.3.An unframed member which stiffens a board,or a series of boards or battens.4.See bedrock.

Ledge Rock

Same as bedrock.

Ledged Door

Same as battened door.

Ledged-and-braced Door

A batten door with diagonal bracing to provide additional reinforcement.

Ledgement Table,ledgment Table

A band course,stringcourse,or belt course,usually molded; carried along the lower portion of a building.


1.In formwork,a horizontal member which is supported by hangers or by upright posts and carries joists.2.A horizontal member which is housed in the studs of balloon framing and carries joists.3.In scaffolding,one of the horizontal members fastened to uprights which support the put-logs and which are at right angles to the wall;they carry the boards on which the workmen stand.4.A flat slab of stone,such as that laid horizontally over a grave.

Ledger Board

1.A ribbon strip.2.One of a number of horizontal boards,joined by vertical supports,as in a fence.

Ledger Plate

1.Same as ledger strip.2.Same asledger, 1.

Ledger Slab

A stone slab set flush in the floor of a church.

Ledger Strip

1.On a beam which carries joists flush with the upper edge of the beam (or girder),a strip of lumber which is nailed to the side of the beam (along its bottom edge),forming a seat for the joists and helping to support them.2.A ribbon strip.


A horizontal,decorative stringcourse of brick or stone.

Left-hand Door

See hand.

Left-hand Lock

A lock for use on a left-hand door.

Left-hand Reverse Door

See hand.

Left-hand Stairway

A stairway having the rail on the left side,in the ascending direction.

Leg Drop

A narrow curtain,usually hung as one  of a pair,on each side of a theater stage,parallel to the footlights.

Legal Open Space

An open space on a premise,such as a yard or court that is permanently dedicated to public use,and that abuts the premise.


A tool used by reed thatchers to align the reeds.

Legitimate House

A theater in which stage plays are produced professionally.


A long tunnel-shaped oven used in annealing glass,usually in a continuous process.

Leipzig Yellow

See chrome yellow.

Leisure Stairs

Stairs having an unusually small slope.


Abbr.for “Lighting Equipment Manufacturers’ Association.”

Lemon Spline

A strip of wood or metal,shaped like a slice of a lemon,which is inserted in a slot formed by two members,each of which is  grooved and butted against the other.

Lengthening Joint

Any joint (e.g.,a halved,lapped,or scarfed joint) used to increase the length of a timber.


1.A glass or plastic having smooth,regular opposite surfaces,shaped to control transmitted light by refraction;used in a lighting unit to focus,disperse,or collimate light rays.2.A combination of such elements.

Lens Panel, Lens Plate

A transparent material in which an array of individual lens elements has been formed;covers lamps in a luminaire to control the direction of emitted light.


Same as letterwood. 

Leper’s Squint

See low-side window. 

Lesbian Cyma

A cyma reversa.

Lesbian Leaf

Same as water leaf.


In ancient Greece,a public portico,club- house,or the like,frequented by the people for conversation or the hearing of news;such buildings were numerous in Greek cities,and their walls often were decorated by celebrated painters.


See pilaster strip.


The person receiving a possessory interest in buildings,property,etc by lease.


The person granting a possessory interest in buildings,property,etc.,by lease.

Let In

In joinery,to insert,to embed,or to house;to secure a timber by inserting it in another.

Let-in Brace

A diagonal brace that is let in to a stud.

Letter Agreement,letter Of Agreement

A letter stating the terms of an agreement between addressor and addressee,usually prepared to be signed by the addressee to indicate his acceptance of those terms as legally binding.

Letter Box

Same as mail box.

Letter-box Backplate

A plate,attached to the interior side of a door,which permits the passage of mail but conceals the opening in the letter box plate.

Liquified Petroleum Gas (LPG)

A petroleum derivative,primarily butane and propane,stored under pressure to maintain its liquid state;used as a fuel for heating and cooking.


A Romanesque pilaster strip.

Listed Building

Any building designated as being of historic architectural interest by one of the many organizations dedicated to the preservation of historic architecture.