What Do Berkeley Buyers Need to Know About BESO?

BESO is Berkeley's Building Emissions Saving Ordinance. It is a City rule, so it applies only in Berkeley and not in the other East Bay cities. Since January 1, 2026, it applies when a single-family home or a duplex is sold.

Condominiums and accessory dwelling units (ADUs) are not covered. Triplexes and fourplexes join on January 1, 2028.

As a Top East Bay Realtor with eXp Realty, helping buyers and sellers in Berkeley and across the East Bay, I bring BESO up in my first conversation with a Berkeley buyer. Most buyers do not hear about it until they are already in escrow, and by then it can add a cost and a deadline you did not plan for.

Before a home is listed, the seller must get a Home Energy Score from a BESO-registered assessor. It is posted in the listing's property notes on the MLS, and the full report is included in your disclosure documents. A score is valid for five years.

As a buyer, read it. It tells you how the home uses energy, which upgrades it may already have, and what it may still need. That helps you plan before you make an offer.

Before the sale closes, the seller chooses one of three paths. Which one they choose changes what you take on, so it belongs in your plan before your offer goes in.

1. The seller completes the upgrades. The home reaches 6 credits and the City issues a Certificate of Compliance before closing. Nothing is left for you to do.
2. The home qualifies for the heat pump exemption. Every unit is already served by an electric heat pump water heater or a heat pump HVAC system. Nothing is left for you to do here either.
3. The seller passes the work to you. You take on the upgrades after closing, and a $5,000 deposit is held, $2,500 from each of you.

Who handles BESO, and how, is part of the negotiation. I would never tell you it is automatic either way.

If the work is passed to you, you have two years after closing to complete the upgrades and reach 6 credits. You can request a one-year extension through the City's portal. When you finish, you file for the Certificate of Compliance, which carries a $150 filing fee.

When the Certificate is issued, you claim the deposit back. You get the full $5,000 refunded, including the $2,500 the seller put in. You can also receive the deposit earlier by showing the City a signed contract with a licensed contractor and your building permits.

The upgrades themselves are a separate cost, and it is the part to understand before you write an offer. A single major upgrade, like a heat pump water heater or a heat pump HVAC system, earns all 6 credits. Smaller upgrades add up. Use the calculator to see which upgrades a home may need and a rough range of what they could cost.

Some are, and the City verifies each one.

• Condominiums and ADUs are not covered.
• All-electric homes with no gas use and capped gas lines can be exempt, with verification.
• First-time buyers enrolled in an income-qualified program, such as CalPLUS or MyHome, can be exempt, with verification.

If you might qualify as a first-time buyer, tell me early so we can confirm it with the City before it affects your contract.

Here is what I look at on every Berkeley home before we write anything:

• The Home Energy Score. I read it first.
• Which path the seller is choosing. Upgrades, the exemption, or passing the work to you.
• The permits for past upgrades. The City counts permitted work from the five years before the sale, so a home may already have credits.
• Whether the home has a heat pump. That can settle it.
• What reaching 6 credits would take. If the work comes to you, we price it before the offer.

Then we talk through what it means for your timeline and your budget.

Here is the order I use:

1. We talk first. I explain BESO and the rest of the steps, so nothing is a surprise.
2. We read the Home Energy Score on each home you like.
3. We check which path the seller chose and ask for the permits or the Certificate of Compliance.
4. We price any work that would come to you with the BESO calculator and your own contractor quotes.
5. We build BESO into your offer. That can mean the deposit split, the price, or the timeline.
6. After closing, if the work is yours, we keep your two-year deadline on the calendar.

Learning about BESO after you are in escrow. By then your leverage is smaller.

Forgetting the upgrades are a separate cost. The deposit comes back to you, but the work is paid for out of pocket.

Counting on a seller's old, unpermitted work. Credits require permitted work that meets code.

Missing the deadline. You have two years after closing, plus a one-year extension if you request it.

Start with the home you are looking at and your timeline. Tanja Odzak is a Top East Bay Realtor with eXp Realty, helping buyers and sellers in Berkeley and across the East Bay, and I will walk you through BESO for each home before you write an offer. The City can update the rules, so check the City's BESO page before you decide. This is general information, not legal, tax, or lending advice.