Santa Clara County, CA Building Safety: Green Building Code (2026)
Key Facts
- Single-family trigger
- 3,000 sq ft or more
- Multi-family trigger
- 25,000 sq ft or more
- Nonresidential trigger
- 25,000 sq ft or more
- Base code
- 2025 CA Green Building Std. Code
Summary
Unincorporated Santa Clara County requires additional green building measures for new single-family homes of 3,000 square feet or more and multi-family projects of 25,000 square feet or more.
A4.601.1 Scope. The measures contained in this appendix are mandatory for new single-family dwellings equal to or greater than 3,000 square feet in area and new multi-family residential dwellings equal to or greater than 25,000 square feet in area. The provisions of this section outline means of achieving enhanced construction or reach levels by incorporating additional green building measures. In order to meet one of the tier levels designers, builders or property owners are required to incorporate additional green building measures necessary to meet the threshold of each level.
(c)Section A4.601.4.2 (Prerequisite and elective measures for Tier 1) is amended to delete subsection 2 (From Division A4.2, Energy Efficiency).(d)Section A4.601.5 (Tier 2) is deleted in its entirety. (Ord. No. NS-1100.138, § 4, 12-9-25)
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Code of Ordinances: Supplement 65).
Full Breakdown
The County adopts the 2025 California Green Building Standards Code as its County Green Building Standards Code under Division C3, Chapter III, and amends its voluntary-measures appendices to make them mandatory above a size threshold. Section C3-35 makes Appendix A4's enhanced construction tier mandatory for new single-family dwellings of 3,000 square feet or more and new multi-family buildings of 25,000 square feet or more; Section C3-36 sets a parallel 25,000-square-foot threshold for new nonresidential buildings under Appendix A5.
Violations & Fines
Plans that omit the required tier measures for a qualifying project are denied plan-check approval by the Building Official until the additional green building measures are incorporated.
Frequently Asked Questions
Does a small home addition trigger the mandatory green measures?
What kind of measures are required above the threshold?
Sources & Official References
Other rules in Santa Clara County
California rules heatmap·Compare Santa Clara County to another location·View the California building safety overview
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