The definition of a well-designed building includes the ability to achieve energy performance levels that reduce the need—and associated cost—for purchased energy to operate the building. At a minimum, this means achieving energy performance that complies with energy-conservation code requirements. It can also mean exceeding the minimum code criteria and striving for higher performance as contained in LEED or other voluntary programs. Achieving building designs that meet targeted energy-performance levels can be realized using many different construction methods and building systems. This course looks at one particular construction type that has been successfully used for low-rise commercial buildings for decades, namely metal building systems. While some have erroneously thought that the use of such systems might mean a compromise on energy performance and sustainability, independent research and actual design and construction results clearly indicate otherwise. In reality, working with a metal building manufacturer to design a complete steel structural system with a coordinated set of building enclosure components can meet or exceed high standards of energy performance in a very cost-effective manner.

All images courtesy of Metal Building Manufacturers Association

Metal building systems are successfully used to achieve energy performance levels that meet and exceed code requirements while offering great design flexibility.

Metal Building Systems Overview

Metal building systems are offered by manufacturers who generally provide a complete package of products and services for a custom-engineered structure and, when specified, the enclosure as well. Services include in-house structural steel engineering and shop drawings for manufactured products. Based on these drawings, manufacturers can then provide full fabrication of primary and secondary structural steel framing, metal roofing, metal wall cladding, and all accessory and trim components. They may also provide supporting products and materials, such as insulation, fenestration, roof curbs, and roll-up doors. Once the total package is fabricated to order, it is shipped to the project location for on-site erection and installation, typically by an independent erector/installer or general contractor. With this working model as a basis, it is easy to see that it is more streamlined and usually more cost-efficient to design and construct a single-source metal building compared to conventional, multiparty construction.

While some may think that all metal buildings are alike, the reality is that metal buildings take several forms. A total metal building system is one that is a complete package of products and services for a custom-engineered structure. This means it is designed, specified, and built using a primary steel structure (main columns, beams, or rigid frames) with secondary steel components (girts, purlins, etc.) and enclosed with metal wall systems (steel panels) plus metal roof systems or panels. Alternatively, a hybrid building can be created that incorporates only the structural portion, while the wall and roof enclosure is constructed from traditional materials and methods, including concrete, masonry, wood, glazing systems, etc. In other cases, only metal siding or roofing may be added to a conventional or existing building.

The basic elements of a total metal building system include the primary and secondary steel structure, metal roofing, and metal siding.

The decision to create either a total metal building or a hybrid one rests with the architect and is based on the relevant design criteria of a particular project. The structural aspects are commonly appealing since they offer complete design flexibility with long clear spans capable of creating very open spaces. Total metal building systems offer faster design, streamlined fabrication, and shortened construction process when compared to conventional construction.

Regarding metal siding and roofing, there are two common forms. One is simply the metal panels in a wide range of profiles, colors, and connection options. This approach requires some type of insulation to be added and installed in the wall or roof system behind the metal panels. The other option is to use an insulated metal panel (IMP), which incorporates rigid insulation sandwiched between an inner and outer metal facing to form a composite panel. This type of product is pre-insulated and has appeal in many building applications. It should be noted, however, that most manufacturers will point out that IMPs do not meet the intent of “continuous insulation” because the panel edges intrude within the foam sheathing insulation. However, IMP designs can provide near equivalent insulation values to continuous insulation.