The National Green Building Standard (NGBS) is the most used green building standard in the US. The 2020 version of the ICC 700 NGBS is now available as a free download for public use (users need to fill out a simple form to get the download link).
The NGBS is a uniquely drafted “standard” in that a local government can adopt it as a residential green building code or any builder can use it on an individual project as a rating system that includes third-party accreditation. The NGBS applies to the design, construction, alteration, enlargement, and renovation of all residential buildings, residential portions of mixed-use buildings, and mixed-use buildings where the residential portion is greater than 50% of the gross floor area; it also applies to subdivisions, building sites, building lots, and accessory structures. The International Green Construction Code incorporates the NGBS as an option to require that single-family dwellings or multi-family dwellings of four stories or less comply with the NGBS.
The NGBS includes high performance building practices in these six areas:
- Lot Design and Development
- Resource Efficiency
- Water Efficiency
- Energy Efficiency
- Indoor Environmental Quality
- Building Operation and Maintenance
There are four certification levels: Bronze, Silver, Gold, and Emerald. They provide options to integrate sustainability and high performance into a project at a level most appropriate for the regulatory environment as well as the customer base in the local housing market.
This fourth edition of NGBS continues the collaboration of the International Code Council and the National Association of Home Builders. The 2020 NGBS, which was ANSI approved earlier this year as a standard, includes these significant changes:
- expanded scope that now includes compliance for the non-residential portion of mixed-use buildings as long as the residential portion of the building is greater than 50% of gross floor area (previous editions defined criteria only for the residential portion of the project);
- expanded scope that also includes assisted living facilities, residential board and care facilities, and group homes;
- new Chapter 12: “Certified Compliance Path for Single-Family Homes, Townhomes and Duplexes,” which provides a new compliance path for single-family dwellings;
- new water efficiency performance path that demonstrates compliance using an index that generates a score relative to a standard baseline home;
- option to use a phased approach for multi-family remodeling projects;
- range of updated performance baselines and references; and
- substantially revised remodeling chapter that offers a choice of prescriptive or performance compliance paths for energy and water efficiency.