If you are reviewing a quote, permit set, or erection drawing and the terminology starts getting in the way, use this page as a reference. These are some of the metal building terms buyers run into most often while comparing options, asking questions, and planning a project.
For deeper planning context, keep the project planning guide, foundation guide, and clear span guide nearby while you read.
Accessory
An add-on product that supplements the shell of the building, such as a door, window, louver, translucent panel, canopy, or roof vent.
Anchor Bolts
Bolts embedded in concrete that connect the steel frame to the foundation. Their location and projection must match the anchor bolt plan exactly.
Bay
The space between primary frames, measured along the length of the building. Bay spacing affects frame count, purlin runs, and future opening locations.
Bearing Endwall
An endwall condition that supports roof load for part of the building but is not intended for future end expansion the way an expandable endwall is.
Clear Span
A framing approach that delivers uninterrupted floor space without interior columns. It is common for hangars, riding arenas, garages, and shops where open maneuvering space matters.
Cladding
The roof and wall panels that enclose the frame. Panel profile, gauge, coating, and attachment method all influence weather resistance and maintenance.
Column
The vertical primary framing member that transfers load into the foundation. On a multi-span building, columns may also appear as interior supports.
Eave Height
The vertical distance from finished floor to the top of the sidewall at the eave. It is one of the first dimensions that changes door options, crane clearance, and usable interior volume.
Endwall
The exterior wall that closes off the building at each end, parallel to the primary frames. Endwall design affects framed openings, expansion options, and bracing strategy.
Footing
The concrete element that spreads building loads into the soil. Footing size and depth depend on loading, frost depth, soil bearing, and code requirements.
Foundation
The total substructure supporting the building, including footings, piers, grade beams, and slab details. A strong shell still fails if the foundation assumptions are wrong.
Framed Opening
A reinforced opening built into the wall or endwall for doors, windows, louvers, or other accessories.
Girt
A horizontal secondary framing member on the wall that supports wall panels and transfers wind loads back to the primary structure.
Grade Beam
A reinforced concrete beam, often integrated with the slab or perimeter foundation, that helps transfer loads between column points and resist lateral movement.
Lean-To
A one-slope attached structure supported in part by the main building. It is often used for covered storage, side expansion, or sheltered work areas.
Main Frame
The primary rigid frame made up of columns and rafters. Main frames carry the major structural loads and establish the building width and height.
Multi-Span
A framing system that uses interior columns to reach larger overall widths than a clear span building can cover economically.
Purlin
The horizontal secondary framing member on the roof that supports roof panels and distributes loads to the primary frames.
Standing Seam
A concealed-fastener roof system designed to accommodate thermal movement better than exposed-fastener panels. It is commonly selected when long-term weather performance matters most.
Wind Uplift
The force of wind trying to pull roof components off the structure. Roof system selection, clip design, and edge detailing all influence uplift resistance.