Home Innovation Insights

New guidance makes tropical green building more feasible.

Michelle Foster
November 9, 2020

Sun-sational, Sustainable Design in the Tropical Zone

Climate change and its effects are accelerating. Consequently, communities are suffering from more frequent and higher intensity climate-related disasters – from hurricanes to wildfires to flooding. With each new event, we have an opportunity to reconsider how we repair and rebuild disaster-damaged homes and how we design and build new homes.

Enhanced resilience is an essential part of any comprehensive green building certification. A green building standard like the National Green Building Standard ICC-700 (NGBS) is designed to eliminate or reduce the environmental impacts of the homes we build (or rebuild), and also includes practices to help homes better withstand future disasters.

Several years ago, the U.S. Department of Housing and Urban Development (HUD) began to require states’ eligibility plans for disaster recovery funding to include a requirement that new homes earn a green or energy-based certification. NGBS Green is one of the certifications recognized by HUD. This is a great public policy approach — stipulate recovery funding is only available if the new housing construction is higher performing and more resilient than what is being replaced.

In September 2017, Puerto Rico was ravaged by Hurricane Maria, a Category 5 hurricane. Maria is the tenth most intense Atlantic hurricane on record and was the most intense tropical cyclone worldwide in 2017. Maria damaged more than 786,000 homes, causing minor damage to some homes, and sweeping others from their foundations. Now, three years later, Home Innovation is proud to have certified the first NGBS Green home in Puerto Rico, with an additional 269 buildings there currently in process to earn NGBS Green certification (43 multifamily buildings and 226 single-family homes). 

The 2015 NGBS and 2020 NGBS work particularly well in places like Puerto Rico that are in the Tropical Zone. However, this was not always the case. Previous NGBS versions did not account for construction practices, resident preferences, or even building product constraints unique to tropical areas. As a result, only five homes in Hawaii had earned NGBS Green certification over the first several years of the program. When the 2015 NGBS Consensus Committee convened, a voting member and code official from Hawaii, Howard Wiig, sought to revise the NGBS so that it was more relevant to tropical climates. Mr. Wiig noted that many homes in Hawaii are already more energy efficient than homes built in the mainland because it is common to only condition bedrooms and not the entire house. As a result of Mr. Wiig’s proposals, the 2015 NGBS recognized buildings that meet the 2015 ICC Section R401.2.1 (Tropical Zone) would achieve the Silver level for energy efficiency. 

With that change, NGBS Green became a viable alternative as a green building certification program for buildings in tropical areas. After the 2015 NGBS was adopted, five multifamily buildings – three in Hawaii and two in St. Thomas, V.I. – earned NGBS Green certification. The certification of these buildings was key in helping the 2020 NGBS Consensus Committee further refine the requirements for buildings in the Tropical Zone. The 2020 NGBS includes important revisions such as recognizing fenestration choices more typical of tropical locales, such as jalousie windows, and providing an energy compliance path for both Silver and Gold certification levels.

In addition, the 2020 NGBS has an entirely new section in Chapter 6: Resource Efficiency, designed to promote more resilient construction. As our understanding deepens of how our buildings impact the environment, and vice versa, the addition of this practice increases the benefits NGBS compliance can bring to homes, apartments, and communities. Also, with HUD federal recovery funding incenting NGBS Green compliance, there is more public policy value when the NGBS promotes more resilient rebuilding post-natural disasters.

The NGBS Green certification process was also modified to better accommodate Tropical Zone buildings. For example, buildings that do not have wall systems with fiberglass insulation behind drywall can skip the rough inspection phase to streamline and consolidate the verification process. Further, we waive the elevation limits for Tropical Zone compliance if the building is designed and constructed without conditioning. We have modified our inspection and documentation guidance for Verifiers working in the Tropical Zone to further assist their verification activities. Last, we are working to process certification documents even faster than usual because we understand homes seeking HUD recovery funding are under strict deadlines for completion. Our proficiency in processing NGBS Green certifications in one business day has helped to remove any lingering barriers to green certification for these properties.

The first NGBS Green certified home in Puerto Rico is located in Bayamón (Spanish pronunciation: [baʝaˈmon]), a municipality in the northern coastal valley. Bayamón is part of the metropolitan area of San Juan and is the island's second most populous city. The home was built on the site of a home destroyed by Hurricane Maria.

The home’s design uses natural cross-ventilation to keep it cool and comfortable without an HVAC system. Jalousie windows help maximize natural ventilation by allowing airflow through the entire window area. Ceiling fans are located throughout the home to increase air circulation even further. The front door is covered by a sizeable overhang which helps keep rain out and residents and guests dry until they can get inside the home. It also includes a balcony area, commonly found in Puerto Rican architectural typology and design. You can find more detail on this project in our case study.

Have questions about getting green in the tropics? Or just need more information on NGBS Green certification? Contact me.

Back to Top

Filed Under:

Add your Comment

All fields marked with * are required