Use of modular construction
Green Building Team on April 1, 2021
Modular building units are popular for certain construction project types, as they are seen as increasing efficiency through reductions in onsite construction time and waste, along with many other benefits. Plus, there is the potential at the end of the initial project life to reuse the modular units.
While LEED does not provide a certification for temporary structures, modular units are not considered a mobile building. As noted in the LEED v4 Minimum Program Requirement (MPR) 1: Must be in a Permanent Location on Existing Land “prefabricated or modular structures and building elements may be certified once permanently installed as part of the LEED project.” There is no specific minimum period of use or lifespan for a building to qualify for certification. This means that modular units are considered part of the LEED project and must be included in all prerequisites and credits attempted.
When to include the modular units as one building
Where modular units are installed as an attached building to the core building structure (for example, a modular wing to a school), they are simply included as part of the LEED project building similar to any added materials, subject to all the same requirements as the core building.
When to use Group certification pathways
If there is a need to separate these structures for the purposes of certification, they would be required to meet the requirements of MPR 2: Must Use Reasonable LEED Boundaries for attached structures. Additionally, as separate certifiable structures within the LEED boundary, the units would be required to certify using the Group certification pathways.
Multiple buildings may be certified as a Group within one LEED project registration, where the entire group, with a single LEED project boundary, receives a single certification.
Similarly, modular units installed permanently within the LEED project site and not attached to the main project building, would be considered certifiable if they were conditioned space and a minimum of 1,000 square feet (93 square meters) of gross floor area; in this case, they would use Group certification pathways alongside the main building.