Existing single-family homes are a challenging building sector to decarbonize; many homeowners face financial constraints, competing priorities, and limited access to technical expertise. Policies designed to accelerate building decarbonization must account for these realities while supporting housing affordability, climate resilience, and emissions reductions.
In Flexible by Design: Rethinking Performance Standards for Single-Family Electrification & Resilience – a paper published as part of ACEEE’s 2026 Summer Study on Energy Efficiency in Buildings – BEI and the City of Berkeley examine this challenge through the Building Emissions Saving Ordinance (BESO) Resilience Standard.
A Flexible, Points-Based Framework for Upgrades at Point of Sale
First adopted in 2015, BESO required home energy assessments when homes were listed for sale. In 2025, Berkeley updated BESO to include a “Resilience Standard” that requires homeowners to select and complete six points’ worth of improvements from a flexible, points-based menu of electrification, energy efficiency, and resilience upgrades. The policy gives credit for prior upgrades, allows extra time for compliance, provides exemptions for certain households and properties, and connects homeowners to incentives and technical assistance.
To help develop BESO’s Resilience Standard, the City balanced its climate objectives with local housing realities. BEI supported the policy development process by analyzing building stock characteristics, potential energy and emissions impacts, and retrofit costs. Engagement with realtors, contractors, and community organizations helped the City identify implementation barriers. Together, technical analysis and stakeholder input informed the selection of home improvements and compliance pathways.
Other jurisdictions can learn lessons from Berkeley's approach. They can:
Build upon existing policy infrastructure and stakeholders relationships.
Use data to inform policy design.
Engage the real estate ecosystem early to identify potential compliance barriers.
Integrate affordability considerations into implementation.
Include resilience, health, and safety upgrades to address broader concerns.
Build in mechanisms for feedback, evaluation, and ongoing iteration.
Berkeley's BESO offers a useful example of how cities can bridge the gap between climate ambition and practical policies that drive single-family home decarbonization.
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