CERTIFICATION AGENCY INTERPRETATION & GUIDANCE
Our NGBS Interpretations and Guidance documents provide clarifications on technical and verification issues related to NGBS Green certification
File Under: Chapter 1: Scope & Administration
2020 NGBS Section 101.2.1 identifies the occupancy types eligible for NGBS compliance.
The 2020 NGBS Consensus Committee intentionally limited this additional eligibility to Group I-1 facilities to ensure that the NGBS applies only to residential-like buildings—not those with hospital-like functions requiring specialized equipment, building systems, or design features.
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File Under: Chapter 11: Existing Building
Most practices within Chapter 11 Existing Buildings are identical to the corresponding New Construction practices within Chapters 5-10.
Practice 11.901.2.1 in the Existing Buildings chapter includes the same text as 901.2.1 in the Indoor Environmental Quality chapter for New Construction. Although point values are not included for 11.901.2.1, they are specified for 901.2.1.
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File Under: Chapter 11: Existing Building
For Existing Buildings, § 11.701.4.6 Fenestration Specifications and § 11.701.4.7 Replacement Fenestration are mandatory practices that require new or replaced fenestration products to meet the values as specified in Table 703.2.5.1.
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File Under: Chapter 9: Indoor Environmental Quality
The ICC 700 National Green Building Standard (NGBS) includes mandatory radon testing and mitigation requirements for buildings in EPA Radon Zone 1, as well as voluntary options in Zones 2 and 3 for certification points. The 2025 NGBS includes updates that increase the stringency of radon-related requirements compared to the 2020 NGBS. This document summarizes the technical requirements for radon testing and mitigation under both NGBS versions. It is important that architects, radon contractors, and other project team members know which NGBS version is being used, because the compliance requirements differ between the two versions.
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File Under: Chapter 9: Indoor Environmental Quality
For 902.3, buildings located in Zone 1 must have at least a passive radon system installed, and points are available when an active system is installed. Buildings located in Zones 2 and 3 earn optional points for both passive and active radon systems.
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File Under: Chapter 6: Resource Efficiency
For these practices, it would be impractical to require strict compliance with the NGBS as written. In existing building renovation projects, replacing the foundation is exceedingly rare—undertaken only when significant structural or moisture issues are identified—because of the excessive effort and impracticality involved.
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File Under: Chapter 9: Indoor Environmental Quality
2020 NGBS Section 902.3.2 requires radon testing for buildings located in EPA-designated Radon Zone 1. If testing reveals radon concentrations above the EPA action level, 4.0 pCi/L, an active radon mitigation system must be installed. However, the NGBS does not require post-installation re-testing to verify that the mitigation system is effective.
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File Under: Chapter 8: Water Efficiency
The 2020 NGBS includes 802.6.5/11.802.6.5 Commissioning and water use reduction for irrigation systems for new and existing buildings. There are five practices under this section, based on the type of landscape or the type of irrigation system used. Each practice is worth three points. Home Innovation interprets that points for these practices can be added together to allow users to claim points using a combination of practices.
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File Under: Chapter 3: Scope
2020 NGBS Section 305 offers an Energy Consumption Reduction Path as one way for buildings to meet the Energy Efficiency requirements in Chapter 11 (Existing Buildings). The Energy Consumption Reduction Path is based on how much remodel project reduces energy use. Section 305 establishes both third-party energy audit/analysis (read: energy modeling) and utility bill analysis as acceptable methods for meeting the Energy Consumption Reduction Path.
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File Under: Chapter 3: Scope
2020 NGBS Section 305 offers a Water Consumption Reduction Path as one way for buildings to meet the Water Efficiency requirements in Chapter 11 (Existing Buildings). The Water Consumption Reduction Path is based on how much the remodel project reduces water use. Section 305 establishes both third-party audit and analysis or utility bill analysis as acceptable methods for meeting the Water Consumption Reduction Path.
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