Time-of-Sale Energy Requirements for Small Residential Buildings

Starting January 1, 2026, anyone selling a single-family home or duplex in Berkeley must:

• Get a Home Energy Score
• Either complete upgrades prior to sale OR defer upgrades to the buyer

Sellers of 3-4 unit residential buildings will need to meet these requirements starting in January 2028.

These rules are part of the Building Emissions Saving Ordinance (BESO), established to lower greenhouse gas emissions and increase resilience in existing buildings. Under BESO, sellers and buyers can choose from upgrades like heat pumps, solar panels, and other improvements.

For more information, see the Compliance Guide for Small Residential Buildings.

Rules apply to 1-4 unit residential buildings

These upgrade requirements apply to: 

• Single-family homes and Duplexes (Starting January 1, 2026)
• Triplexes and Fourplexes (starting January 1, 2028). Until phased in, these buildings are only required to complete an energy assessment prior to listing.

The requirements do not apply to condominiums and Accessory Dwelling Units (ADUs).

Seller Requirements

Step one: Get a Home Energy Score

Before listing a building for sale, sellers must:

1. Hire a qualified Home Energy Score Assessor from the list of Registered BESO Energy Assessors.
2. Get a separate score for each unit (for multi-unit buildings).
3. Post the score(s) in the property’s MLS listing in the Property Notes section. Follow the instructions in the detailed guide on how to include the Home Energy Score on the MLS.
4. Include the Home Energy Score Report in disclosure and transfer documents.

Home Energy Score Reports are valid for five years. Failure to complete and disclose the report results in a $500 non-compliance fee.

Step two: Complete upgrades, qualify for exemption, or defer upgrades to buyer

Sellers must choose one of three options before the sale is finalized:

Option one: Complete upgrades before selling to meet the Resilience Standard

Install one or more upgrades (see the list of options below) to achieve at least six credits. You can get credit for any upgrades that you made in the five years before selling.

Submit the required documentation on the BESO Portal and pay the $150 filing fee to receive a BESO Certificate of Compliance. If needed, a paper BESO application with payment by check may also be submitted by mail. 

Option two: Qualify for a heat pump exemption

If the home already has an electric heat pump for water heating, space heating, or both, the building may be exempt from additional upgrades. 

To qualify: 

• All dwelling units in the building must be served by an electric heat pump water heater or heat pump HVAC system.
• Submit the required documentation (Building Permit or Home Energy Score Report) on the BESO Portal and pay the filing fee to receive a BESO Certificate of Compliance.

Option three: Defer upgrades to the buyer

If you do not complete the upgrades before sale, you can defer responsibility to the buyer.

To defer upgrades:

• Coordinate with the buyer and title company to submit a BESO Upgrade Deposit Form.
• Deposit $5,000 to the City ($2,500 each from the seller and buyer).

The buyer will have two years from the date of sale to complete upgrades. The City will hold the $5,000 deposit and refund it to the buyer to offset the cost of the upgrades once they are complete.

Buyer requirements

If the seller deferred the upgrades, the buyer must:

1. Coordinate with the seller and title company to submit a BESO Upgrade Deposit Form and deposit $5,000 to the City ($2,500 each from the seller and buyer).
2. Complete upgrades to meet the Resilience Standard:
   1. Install one or more upgrades to achieve at least six credits
   2. Complete upgrades within two years of purchase. (You can request a one-year extension through the BESO portal.)  
   3. Submit documentation on the BESO Portal and pay the $150 filing fee to receive a BESO Certificate of Compliance.
3. Request a deposit refund once the upgrades are complete:
   1. Submit a BESO Upgrade Deposit Refund Form along with the BESO Certificate of Compliance.
   2. Receive the $5,000 refund. 

Complete upgrades to earn credits

To meet the Resilience Standard, each unit in a 1-4 unit building must earn at least six credits by completing one or more upgrades from the list below:

• Heat Pump Water Heater (6 credits)
• Heat Pump HVAC (6 credits)
• Knob & Tube Replacement with Pre-Wiring of 240v receptacles (6 credits)
• Smart Service Panel (6 credits)
• Electrical Service Panel Upgrade (6 credits)
• Solar PV (3 credits)
• Battery Energy Storage System (3 credits)
• EV Charger (2 credits)
• Electric or Induction Range (2 credits)
• Window Replacements (2 or 4 credits)
• High Home Energy Score (9 or 10) (2 credits)
• Wall Insulation (2 or 4 credits)
• Attic Insulation (2 credits)
• HVAC Duct Improvements – sealing, insulation, or replacement (2 credits)
• Whole-house Fan (2 credits)
• Electric Clothes Dryer (1 or 2 credits)
• Prewiring & 240v receptacles (1 or 2 credits)
• Floor/Crawlspace Insulation (1 credit)
• Greywater System (1 credit)
• Air Sealing (1 credit)

Click the link for each option to ensure you meet the specific installation criteria and verification requirements.  

Work must be permitted and meet code requirements on the date of permit application.

If a building already has an electric heat pump for water or space heating, the home may qualify for a Heat Pump Exemption.

Exemptions and exceptions

Buildings may be eligible for an exemption or exception:

• All-Electric Homes: Homes that use no gas and have capped gas service lines are exempt. Verification is required.
• First-Time Homebuyers: Buyers enrolled in an income-qualified first-time buyer program (such as CalPLUS or MyHome) are exempt. Verification is required.
• Early Refund Exception: A buyer may receive their $5,000 Resilience Upgrade deposit before fully completing the upgrades. To qualify for an early refund, the buyer must have a signed contract with a licensed contractor and obtained building permits. 

Contact the BESO Helpdesk at BESO@BerkeleyCA.gov or call (510) 981-7465 for more information or to apply for an exemption or exception.

fees

• BESO Certificate of Compliance Application Filing Fee: $150

• Home Energy Score Non-Compliance Fee: $500