The 2020 National Green Building Standard (NGBS) includes some significant revisions from previous versions. One of the most significant is the scope expansion that allows the NGBS to be used for the design and construction of both the residential and non-residential space in mixed-use buildings. Prior to the 2020 NGBS, only the residential portion of mixed-use buildings could seek NGBS Green certification — the non-residential portion was either not included, or was forced to seek certification from another program.
Mixed-Use Buildings: The Concept Alone is Sustainable
In 2017, Home Innovation’s Market Research team estimated that at least 51% of all new multifamily buildings being constructed were mixed-use, typically with the first one or two floors designated as retail/commercial space and apartments above those floors. Mixed-use buildings are an increasingly important component for sustainable development nationwide. A mixed-use building not only sustainably utilizes resources and precious space, but also provides building occupants and nearby residents with spaces that can integrate work, home, shopping, transportation, and even green spaces. Buildings with mixed uses can provide efficiencies far beyond traditional energy and water efficiency.
2020 NGBS Non-Residential Provisions
The 2020 NGBS Consensus Committee sought to remedy the non-residential restriction and revised the NGBS to provide provisions for an entire mixed-use building to earn NGBS Green certification. First, the scope was revised to explicitly allow mixed-use buildings where the residential portion of the building is greater than 50% of the gross floor area. The scope expanded to allow these non-residential spaces to seek and earn certification but left that as optional; builders and developers can continue to seek NGBS Green certification for just the residential portion of any building. However, if a builder/developer would like to have the non-residential space NGBS Green Certified, the residential portion must also be certified. Second, the Consensus Committee added a new chapter (Chapter 13) that details the compliance provisions for two certification paths: Core-and-Shell; and Fully Fitted Out and Equipped. Unlike the compliance provisions for most of the NGBS, Chapter 13 practices are all mandatory – i.e., there are no performance levels for non-residential space; it is either compliant/"Certified" or it is not.
Core-and-Shell Certification
Mixed-use building developers can select to earn Core-and-Shell certification after the building is completed, but before commercial/retail tenants are in place. This allows the building developer or owner to obtain a green certification for the entire building immediately upon completion of construction. This can be desirable for marketing purposes, financing requirements, investor preferences, or other regulatory needs (such as building code or land entitlement obligations).
Core-and-Shell construction — a recent U.S. adaptation to modern construction techniques — creates a blank canvas out of the building’s non-residential space. This construction method plans, designs, and builds the core (building interior), which is covered or surrounded by shell (building exterior). Once the core and shell structures are built, the internal architectural elements (fittings) can be integrated gradually as dictated by the leasing schedule and the tenants’ needs.
There are several benefits to the Core-and Shell method. First, it speeds up the design and build process. Defining the core and shell elements of the building upfront allows progress to be made in the design of other portions of the building while the longer-lead items of the core and shell are implemented. Once those elements have been planned, work can proceed without having to wait on the interior details. Second, this method can provide a better finish for each tenant since they are working from a blank canvas and can create a space that suits their specific needs, rather than altering an existing fit-out. There is also more time to develop the internal fit-out, allowing for a more careful and specific design.
For the NGBS Green Core-and-Shell certification, the building must be compliant with the NGBS Green practices regarding the exterior air barrier, insulation, air sealing, and fenestration. These practices for the non-residential space are generally aligned with those for the residential space to ensure both spaces are similarly high performing.
Developers interested in seeking Core-and-Shell certification should download a free NGBS Green Scoring Tool for multifamily buildings (select either New Construction or Renovation) and complete the relevant worksheet. When your Verifier registers the building, he/she should select the “Core-and-Shell” option. As always, registration is free but mandatory and must be completed by an accredited NGBS Green Verifier. The Verifier will inspect the building at least twice – once at the pre-drywall stage, and once at construction completion. The Verifier will complete and submit verification reports on their inspection findings for both residential and non-residential space. Once the final report is reviewed and accepted, Home Innovation will issue the NGBS Green certification for the entire building. There is a small additional certification fee for the Core-and-Shell certification.
Fully Fitted Out and Equipped Tenant Space Certification
Developers may also select to seek certification for the Fully Fitted Out and Equipped tenant space. Chapter 13 of the 2020 NGBS includes the green practices that must be successfully incorporated for this certification path. To start, the building must be compliant with all Core-and-Shell practices. Chapter 13’s green practices generally complement the NGBS’s green practices for the residential portion of the building and cover building aspects such as bicycle parking; resource efficiency; energy efficiency; water efficiency; indoor air quality; and operation, maintenance, and building owner education. The practices are diverse as they were intended to cover a broad range of commercial uses from restaurants, to retail stores, to office space. To earn certification, all relevant practices must be successfully completed.
Developers interested in seeking Fully Fitted Out and Equipped tenant space certification should download a free NGBS Green Scoring Tool for multifamily buildings (select either New Construction or Renovation) and complete the relevant worksheet. When your Verifier registers the building, he/she should select the “Fully Fitted Out and Equipped” option. For this certification path, depending on the tenant schedule for completing the commercial spaces, the Verifier may have to make multiple additional verification inspections of the non-residential space. Depending on the leasing schedule, the developer may select to first complete the NGBS Green process for the residential portion and the Core-and-Shell certification, and then come back for the Fully Fitted Out certification. Alternatively, the developer (or even the tenants) can select to certify only a portion of the non-residential space. If the space(s) meets the NGBS requirements, Home Innovation can issue a certificate of conformance. There is a small additional certification fee for the Fully Fitted Out and Equipped certification. Home Innovation can provide one NGBS Green certificate for the entire building or individual tenant certificates, as desired.
Mixed-use buildings are inherently sustainable — and now they can earn NGBS Green certification to prove it. Interested in getting your mixed-use project NGBS Green Certified? Contact us – we are happy to help you get started.
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