Marnella Homes Earns First 2020 NGBS Green Certification

Washington-based Marnella Homes' Greenwich Condos, located in Portland, Ore., was the first building to be NGBS Green Certified under the 2020 National Green Building Standard (NGBS). The building earned the highest level of certification available — Emerald — and was the first to earn the new NGBS Green+ WELLNESS badge, which recognizes buildings that are higher performing across a suite of NGBS practices that are influential to human health. The builders of the nine-unit condo building focused on residents' health, comfort and energy efficiency. The building is located in a walkable community (Walk Score 84 and Bike Score 100) with easy access to public transit. Features include:
  • Fresh air exchange via a whole-home fan;
  • High efficiency ducted mini-splits;
  • Above-code insulation to improve both acoustics and energy efficiency;
  • South-facing windows for passive lighting;
  • Private outdoor space for each homeowner;
  • Advanced framing; and
  • Rooftop solar panels providing 1.95 kW for each home (which offsets approximately 30% of the each unit's power needs).
The project was also designed and constructed to provide these features at an attainable price for the target market: singles and young couples. “I wanted these to be healthy, comfortable, energy efficient and provide features that our buyers aren’t seeing at this price range,” noted Tony Marnella, NAHB member and owner of Marnella Homes. Marnella also shared details about the project and healthier homes in general with Michelle Foster of Home Innovation Research Labs in Episode 3 of Housing Innovation Alliance's podcast. Read more about Greenwich Condos, its high-performance strategies and wellness features in this case study. The ICC700 National Green Building Standard® — the first residential green building rating system approved by the American National Standards Institute (ANSI) — has been used by building professionals for more than a decade. The standard provides practices for the design and construction of all types of green residential buildings, renovations and land developments. It provides architects, builders and developers the flexibility needed to design and construct homes and mixed-use buildings that are sustainable, cost-effective and appropriate for a home’s geographic location. The 2020 NGBS offers builders and developers additional compliance paths for certification, including full certification of mixed-use buildings (with at least 50% residential space) and an entry-level certified path for single-family builders. Nearly 400 projects have already been registered since the standard was published in April 2020. Visit for more information on how to certify a project to the NGBS, purchase a hard copy or download a free pdf of the reference standard. For more details about NAHB’s sustainable and green building programs, contact Sustainability and Green Building Program Manager Michelle Diller. To stay current on the high-performance residential building sector, follow NAHB's Sustainability and Green Building team on Twitter.

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