Construction glossary, A to Z
A plain-language construction glossary from A to Z for procurement, steel framing, prefab and building envelope terms, with short entries linked to fuller explanations.
This glossary explains the terms that come up when you buy construction materials and prefab systems. Each entry is short and plain, and links to a fuller page. Definitions here are for understanding only; where your contract defines a term differently, the contract controls, and technical suitability is for the engineer of record and the local authority.
Procurement and documents
- Bill of quantities and bill of materials: itemised lists of work or components.
- Material takeoff: counting quantities from drawings.
- Request for information, request for quotation, request for proposal.
- Purchase order, change order.
- Submittal, shop drawing, as-built drawing.
- Specification, scope of work.
Schedule and delivery
- Lead time, long-lead item, critical path.
- Design freeze, value engineering, constructability.
- Landed cost, Incoterms.
- Factory acceptance inspection, punch list.
Offsite and prefab
- Design for manufacture and assembly.
- Offsite construction, prefabrication, panelization, volumetric modular construction.
Steel framing and structure
- Cold-formed steel, light-gauge steel, structural steel.
- Stud, track, joist, truss, bracing, deflection track.
- Load-bearing wall, non-load-bearing partition, shear wall.
- Galvanization, corrosion protection.
Envelope and performance
- Thermal bridge, thermal break, R-value, U-factor.
- Air barrier, water-resistive barrier, vapor retarder, rainscreen, flashing.
- Fire-resistance rating, acoustic rating.
Documents and data
- BIM object, CAD detail.
- Environmental product declaration, health product declaration, safety data sheet.
- Mill test report, certificate of conformity.
How to use these entries
Read terms in the order your project meets them: documents first, then schedule, system, envelope, and finally records. For the full buying process see the materials procurement guide for developers and the prefab terminology guide. For standards behind the terms, the bodies themselves, such as ISO, ASTM and CFSEI, publish the authoritative text. Keep your own list of terms that differ in your contract, and put it in your document library.
A
- Acoustic ratingAn acoustic rating describes how well a wall, floor or product blocks or absorbs sound, using standardized test metrics.
- Air barrierAn air barrier is a system of materials and joints that controls uncontrolled air movement through the building envelope.
- As-built drawingAn as-built drawing records the work as it was actually constructed, including changes made during the build, and is handed to the owner at completion.
B
- Bill of materialsA bill of materials (BOM) is a structured list of every component, part and quantity needed to build one product or assembly, such as a wall panel or a module.
- Bill of quantitiesA bill of quantities (BoQ) is an itemised list of the work in a project, each item with a description and a measured quantity, used so bidders price the same scope.
- BIM objectA BIM object is a digital model of a building product that carries geometry plus data such as size, material and performance properties.
- BracingBracing is a set of members or connections that stops a frame from racking or buckling, and carries lateral loads such as wind to the foundation.
C
- CAD detailA CAD detail is a drawing, usually 2D, that shows how parts of a construction assembly connect at a specific location.
- Certificate of conformityA certificate of conformity is a signed statement that a product or batch meets the stated standard or specification.
- Change orderA change order is a written agreement that modifies a contract’s scope, price or time after signing, approved by the parties under the contract’s change procedure.
- Cold-formed steelCold-formed steel (CFS) is steel sheet shaped into structural members at room temperature, such as studs and tracks, used widely in framing walls, floors and roofs.
- ConstructabilityConstructability is how easily and efficiently a design can be built, and constructability review brings builders into design to find problems before they reach the site.
- Corrosion protectionCorrosion protection is the set of coatings, materials and design details used to keep metal from degrading in its service environment.
- Critical pathThe critical path is the longest chain of dependent tasks in a schedule, so any delay to a task on it delays the whole project finish date.
D
- Deflection trackDeflection track is a steel track with deep legs that lets a wall stay fixed to the floor while the structure above moves vertically.
- Design for manufacture and assemblyDesign for manufacture and assembly (DfMA) is a design approach that shapes a product so it is easy to make in a factory and quick to assemble on site.
- Design freezeA design freeze is the agreed point after which the design of a defined scope stops changing without formal approval, so ordering and fabrication can proceed safely.
E
F
- Factory acceptance inspectionA factory acceptance inspection is a check, done at the manufacturer before shipping, that the goods match the order and the quality requirements.
- Fire resistance ratingA fire resistance rating states how long a building element can contain fire or keep its function in a standard test, usually given in hours.
- FlashingFlashing is thin, water-shedding material installed at joints, openings and edges to direct water away from the structure.
G
H
I
J
L
- Landed costLanded cost is the total cost of getting a product to your door: the price plus freight, insurance, duties, taxes and handling.
- Lead timeLead time is the elapsed time between placing an order or starting a task and receiving the result, which in construction drives when materials must be ordered.
- Light-gauge steelLight-gauge steel is another name for thin steel sheet shaped into framing members, used interchangeably with cold-formed steel in most building contexts.
- Load-bearing wallA load-bearing wall carries loads from floors, roofs or walls above down to the foundation, so altering it requires engineering review before any work.
- Long-lead itemA long-lead item is a material or component that takes so long to approve, make and deliver that it must be ordered early to avoid delaying the project.
M
- Material takeoffA material takeoff is the process of measuring drawings to count and total the materials a project needs, such as linear metres of track or sheets of board.
- Mill test reportA mill test report, or MTR, is a document from the steel producer certifying the chemical and mechanical properties of a specific heat or lot of material.
N
O
P
- PanelizationPanelization is building flat wall, floor or roof panels in a factory, framed and sometimes sheathed, then shipping and joining them on site.
- PrefabricationPrefabrication is the manufacture of building parts or assemblies before delivery to site, so they can be installed rather than built piece by piece on location.
- Punch listA punch list is a record of small items that remain unfinished or defective near the end of a construction project and must be fixed before final acceptance.
- Purchase orderA purchase order (PO) is the buyer’s written commitment to buy specified goods or services at agreed terms, and it becomes a contract once the seller accepts.
R
- R-valueR-value measures a material's resistance to heat flow; a higher R-value means better insulating performance for that layer.
- RainscreenA rainscreen is a wall system with cladding held off the backup wall by a drained and ventilated cavity, so water and moisture can escape.
- Request for informationA request for information (RFI) is a formal written question sent during bidding or construction to clarify unclear, missing or conflicting project documents.
- Request for proposalA request for proposal (RFP) invites firms to propose how they would solve a problem, with approach, team, schedule and price, so the buyer can evaluate more than cost.
- Request for quotationA request for quotation (RFQ) asks suppliers or subcontractors to price a clearly defined item or scope, so the buyer can compare prices on equal terms.
S
- Safety data sheetA safety data sheet, or SDS, is a standard document describing a chemical product's hazards, safe handling, storage and emergency measures.
- Scope of workA scope of work defines exactly what work a party will perform, what is included and excluded, deliverables, standards and timing, so price and responsibility are clear.
- Shear wallA shear wall is a braced wall panel designed to resist lateral forces such as wind or earthquake in the plane of the wall.
- Shop drawingA shop drawing is a detailed fabrication or installation drawing prepared by a contractor, fabricator or supplier to show exactly how a component will be made and fitted.
- SpecificationA specification is the written part of the construction documents that sets the required materials, standards, workmanship and testing, complementing the drawings.
- Structural steelStructural steel is steel shaped and specified to carry significant loads in buildings, typically hot-rolled beams, columns and plates, fabricated and connected to a design.
- StudA stud is a vertical framing member in a wall, spaced along a track or plate, to which sheathing and boards are fixed; it may be timber or steel.
- SubmittalA submittal is a package of product data, samples or calculations that a contractor sends to the design team for review before ordering or installing a specified item.
T
- Thermal breakA thermal break is a low-conductivity element placed in an assembly to interrupt the path of heat through a more conductive material.
- Thermal bridgeA thermal bridge is a part of an assembly that conducts heat more easily than the material around it, creating a path for heat loss or gain.
- TrackTrack is the U-shaped cold-formed steel channel that runs along the floor and ceiling of a framed wall and holds the studs in place.
- TrussA truss is a triangulated frame of members that spans an opening, most often to carry a roof or floor with less material than a solid beam.
U
V
- Value engineeringValue engineering is a structured review of a design to find options that deliver the required function at lower cost or better value, without cutting required performance.
- Vapor retarderA vapor retarder is a layer that slows the diffusion of water vapor through a wall, floor or roof assembly.
- Volumetric modular constructionVolumetric modular construction builds complete three-dimensional units, often with finishes and services, in a factory and transports them to site to be stacked or placed.
W
Digital Oro International advertises on The Company Chronicle. This guide was written by our editorial team from public sources and general professional practice; it does not describe a guarantee, quote or offer from Digital Oro International. Confirm current terms, prices and availability with the operator before you decide.