Pre-Engineered Steel Building Structures (PEBS)

The PEB Steel Structure of a Pre-Engineered Steel Building generally accounts for over 80% of the weight of the Pre-Engineered Steel Building. This 80% is an average and may change plus or minus 10% depending on the presence of mezzanines, crane runway beams, type of Panels used and the amount of building accessories that are included in a building. The unit of measure for PEB Steel Structures is metric ton (MT). As a general average, one square meter (1 m²) of PEB Steel Structure weighs 25 kg. Thus one MT of PEB Steel Structure = 40 (1000/25) m² of building foot print. The PEB Steel Structure is made up of frames, secondary members and steel standard buyouts.

Frames in the PEB industry often refer to primary built-up & hot rolled members. Constant depth or tapered depth built-up members generally account for over 90% of the weight of frames while hot rolled members generally account for the remaining 10%.


A pre-engineered metal building, also known as a pre-manufactured or pre-fabricated metal building, is designed to specification at the workshop. There are numerous designs available, all of which can be customized as needed.Specialized software like Metal Building Systems (MBS) and other design tools are utilized.


Since these buildings are not created until the design is complete, the members and panels are created as needed, minimizing the amount of steel required and resulting in a lighter-weight building. Every piece is sourced from the manufacturer.

Each piece is precision rolled, cut, punched, and marked to make assembly as easy as possible once the kit reaches the jobsite. Everything is included in the kit: members, panels, and fasteners, which have all been tested before transporting to site.


A pre-engineered building has the advantage of a known weight, simplifying foundation design. Also, since pre-engineered buildings use customized members, less steel is needed to create them and results in a lighter building that needs a less complex or heavy foundation.


Pre-engineered primary and secondary framing members are custom-made for each building designed. Instead of standard I-sections, tapered members that are sturdy yet light-weight can be used in the primary frame. Secondary members are steel Z and C shapes; all girts and purlins are lightweight steel as well.

No field cutting is needed to create frame members to fit; they simply bolt together as designed as punched in the factory.

Expansion and Repair

Pre-engineered steel buildings are eminently expandable and easily customized to new uses. New sections are readily bolted onto any side or added to the top of an existing structure.

Original, engineer-stamped documents assist future redesign work and streamline the permitting process. If a section of the building is damaged, repairs can be performed easily, often using replacement parts from the original manufacturer.


Pre-engineered steel buildings have come a long way from the simple sheds you see along the side of the road. A multi-storey or wide-span building can be pre-engineered as can anything in between, built to last for decades and able to be disassembled and moved if needed.

Every pre-engineered building is designed to meet the local building standards and requirements. Specialized connections and framing are designed in for seismically active regions or any other special environmental concern.

Secondary Members in the PEB industry refer mostly to longitudinal roof and wall members that are roll formed from galvanized coils or press broken from narrow galvanized sheets. The raw material of these members is stocked in five thickness: 1.5, 1.6, 1.8, 2 & 2.5mm.

The following building components are considered secondary members:
  • Z" sections acting as longitudinal roof purlins and longitudinal wall girts that connect to columns & rafters.
  • And support exterior roof and wall panels.
  • Eave struts located at the building eaves (corner of roof and wall sheeting along sidewalls also providing)
  • Bracing for frames and supporting roof and wall panels.
  • "C" sections used primarily in framed openings and as a transition member between partial block walls and wall panels.
  • Mezzanine Deck used to support concrete slabs in second level flooring.
  • Base angles, gable angles, and mezzanine edge angles.
  • Valley gutters in Multi Gable Buildings.
  • Steel Standard Buyouts (SBO): These are items that are required in almost every PEB Steel Structure. They are manufactured by others and stocked by the PEB manufacturer. They include Anchor Bolts, Connection Bolts, Sag Rods and Cable Bracing Components.