Berkeley’s 2026 BESO Requirements: Complete Guide for Home Sellers & Buyers

Starting January 1, 2026, Berkeley’s Building Emissions Saving Ordinance (BESO) introduces major changes that directly impact homeowners, buyers, and real estate professionals. This guide explains everything you need to know to stay compliant and optimize your property for the future.

What Is Berkeley’s BESO Program?

The Building Emissions Saving Ordinance (BESO) is a city initiative designed to reduce greenhouse gas emissions by improving energy efficiency in residential buildings.

Residential properties account for a significant portion of Berkeley’s emissions, making energy upgrades a key priority for the city’s climate goals. 

What Changes in 2026?

• Mandatory Home Energy Score (HES) before listing a property
• Required energy efficiency upgrades (Resilience Standard)
• New compliance pathways for sellers and buyers
  
  

These updates shift BESO from a simple assessment requirement to a performance-based compliance system. 

Home Energy Score (HES): Now Mandatory

Before listing your home, sellers must:

• Hire a certified assessor
• Obtain a Home Energy Score (1–10 scale)
• Include the score in the MLS listing

Failure to comply may result in a $500 penalty. 

Resilience Standard: Energy Upgrades Explained

Homes must complete upgrades totaling at least 6 credits. These improvements can include:

• Heat pump water heaters or HVAC systems
• Solar panels and battery storage
• Electrical panel upgrades
• Insulation and air sealing
• EV chargers and efficient appliances

This flexible system allows homeowners to choose upgrades based on budget and property conditions. 

Who Is Responsible for the Upgrades?

Option 1: Seller Completes Upgrades

• Complete improvements before listing
• Obtain compliance certificate
• No escrow deposit required

Option 2: Buyer Completes Upgrades

• $5,000 escrow deposit ($2,500 each party)
• Buyer has up to 2–3 years to comply
• Refund issued after completion

This flexibility helps align compliance with financial and strategic goals. 

Why This Matters for Real Estate

The 2026 BESO update is more than regulation—it’s a shift toward:

• Electrification of homes
• Higher property transparency
• Energy-efficient housing stock

Homes with completed upgrades may become more attractive to buyers and better positioned in the market.

Key Deadlines

• Jan 1, 2026: New rules take effect
• Before listing:  Energy assessment required
• Within 2 years: Upgrade completion (if deferred)

Quick Summary 

Berkeley’s 2026 BESO requires:

• A Home Energy Score before listing
• Energy upgrades totaling 6 credits
• Compliance by seller or buyer
• MLS disclosure of energy score
  
  

Final Thoughts

Whether you're buying or selling, planning is essential. Understanding BESO ensures compliance, avoids penalties, and positions your property for Berkeley’s energy-efficient future.

Frequently Asked Questions (FAQ)

Is the Home Energy Score required before listing?

Yes. Sellers must complete the assessment before listing the property.

How many credits are required?

Homes must achieve at least 6 upgrade credits.

Can buyers handle the upgrades?

Yes, but they must complete them within 2–3 years after purchase.

What happens if I don’t comply?

You may face financial penalties and delays in the sale process.