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Home / Berkeley / Building Emissions Saving Ordinance (BESO)

Berkeley · BESO time-of-sale

Berkeley BESO questions before listing a home

Use this general guide to identify the official BESO page for the building category, check the City portal, and prepare questions about assessment, upgrade, exemption, or deferral paths. It does not determine a building's BESO status.

General information onlyNo property outcomeOfficial sources controlSale-triggered topic to verify

Last reviewed by Bay Sale Ready: July 18, 2026. Information may have changed since our last review. Verify current requirements and status directly with the responsible agency before relying on it.

Start with the official source

Use Berkeley's BESO portal to check the building record, then confirm the correct building category in the City instructions.

Verify at the official source ↗

Last reviewed by Bay Sale Ready: July 18, 2026. Information may have changed since our last review. Verify current requirements and status directly with the responsible agency before relying on it.

Opening a record or portal does not mean that Bay Sale Ready has determined coverage, validity, responsibility, or whether a transaction may close.

Official-source dossier

Berkeley BESO official-source navigation map

This navigation map keeps building-category instructions, the small-residential guide, and the BESO Portal in separate lanes. It does not select a building path, interpret a portal label, calculate credits or dates, or decide what any transfer needs.

Official source record label

One- and two-unit City materials

What the linked City of Berkeley · BESO source says this record represents: The City page describes the small-residential time-of-sale framework for single-family homes and duplexes and links the related guide, portal, application, and deposit material.

Keep this source or record separate: The City page is a research source. Bay Sale Ready does not determine the building category or choose an assessment, upgrade, exemption, or deferral path.

Questions to verify with the responsible agency

  • Which building category does BESO record for the property being researched?
  • Which report, certificate, or other City material does BESO identify for the planned transfer?

This card names sources, records, and agency questions. Bay Sale Ready does not identify a record, document, status, or next action for any property or transaction.

Verify at the official source: Time-of-Sale Energy Requirements for Small Residential Buildings ↗

Last reviewed by Bay Sale Ready: July 18, 2026. Information may have changed since our last review. Verify current requirements and status directly with the responsible agency before relying on it.

Official source record label

Three- and four-unit transition materials

What the linked City of Berkeley · BESO source says this record represents: The administrative regulations describe assessment methods and a staged framework for three- and four-unit buildings around the January 2028 transition.

Keep this source or record separate: This card does not select an assessment method or calculate a transition date. Confirm the building category, assessment record, and timeline with BESO.

Questions to verify with the responsible agency

  • Which assessment method does BESO identify for the building and listing date?
  • Which phase and supporting City document does BESO associate with the planned transfer?

This card names sources, records, and agency questions. Bay Sale Ready does not identify a record, document, status, or next action for any property or transaction.

Verify at the official source: BESO Administrative Regulations, Version 5.0 ↗

Last reviewed by Bay Sale Ready: July 18, 2026. Information may have changed since our last review. Verify current requirements and status directly with the responsible agency before relying on it.

Official source record label

Condominium and ADU City guidance

What the linked City of Berkeley · BESO source says this record represents: The April 2026 City guide describes different treatment for building and unit categories and discusses exception and exemption records within the small-residential framework.

Keep this source or record separate: A building label or unit type does not create a Bay Sale Ready outcome. Confirm whole-building, HOA, mixed-use, and unusual ownership questions with BESO.

Questions to verify with the responsible agency

  • How does BESO distinguish the individual unit from the whole building record?
  • Which City confirmation does BESO identify for the building and transfer facts?

This card names sources, records, and agency questions. Bay Sale Ready does not identify a record, document, status, or next action for any property or transaction.

Verify at the official source: BESO Compliance Guide for Small Residential Buildings ↗

Last reviewed by Bay Sale Ready: July 18, 2026. Information may have changed since our last review. Verify current requirements and status directly with the responsible agency before relying on it.

Official source record label

Multifamily and commercial City materials

What the linked City of Berkeley · BESO source says this record represents: The separate City page describes the assessment and time-of-sale materials for multifamily and commercial building categories.

Keep this source or record separate: This source is separate from the small-residential page. Bay Sale Ready does not classify a building by unit count, use, size, ownership, or portal record.

Questions to verify with the responsible agency

  • Which City page does BESO identify for the building category?
  • Which assessment confirmation, form, and portal record does BESO want reviewed?

This card names sources, records, and agency questions. Bay Sale Ready does not identify a record, document, status, or next action for any property or transaction.

Verify at the official source: Time-of-Sale Energy Requirements for Multifamily and Commercial Buildings ↗

Last reviewed by Bay Sale Ready: July 18, 2026. Information may have changed since our last review. Verify current requirements and status directly with the responsible agency before relying on it.

Official source record label

BESO Portal record

What the linked City of Berkeley · BESO source says this record represents: The City BESO pages link the portal for building records, submissions, and agency workflow material.

Keep this source or record separate: A portal label is agency-reported information, not a Bay Sale Ready finding about listing, transfer, document, or closing status.

Questions to verify with the responsible agency

  • Which building identifier, category, record label, and date does the portal display?
  • What does BESO say the displayed label and attachments mean for the planned transfer?

This card names sources, records, and agency questions. Bay Sale Ready does not identify a record, document, status, or next action for any property or transaction.

Verify at the official source: BESO Portal ↗

Last reviewed by Bay Sale Ready: July 18, 2026. Information may have changed since our last review. Verify current requirements and status directly with the responsible agency before relying on it.

Keep official records and supporting materials separate

  • Building category and source path: The small-residential and multifamily or commercial pages describe different source paths. Bay Sale Ready does not choose between them. Verify at the official source ↗

    Last reviewed by Bay Sale Ready: July 18, 2026. Information may have changed since our last review. Verify current requirements and status directly with the responsible agency before relying on it.

  • Assessment report and City certificate: An assessment report, assessment confirmation, application, and BESO certificate are distinct records and should not be relabeled as one another. Verify at the official source ↗

    Last reviewed by Bay Sale Ready: July 18, 2026. Information may have changed since our last review. Verify current requirements and status directly with the responsible agency before relying on it.

  • Portal label and agency decision: A portal display and BESO's interpretation of the building or transfer record are separate. Confirm the record meaning directly with BESO. Verify at the official source ↗

    Last reviewed by Bay Sale Ready: July 18, 2026. Information may have changed since our last review. Verify current requirements and status directly with the responsible agency before relying on it.

Version warning

Three- and four-unit materials need direct BESO confirmation

The small-residential page describes a January 2028 phase change, while the administrative regulations and multifamily materials describe assessment choices during the transition. Bay Sale Ready does not merge those sources into a property path; ask BESO which source, method, and date control.

  • Time-of-Sale Energy Requirements for Small Residential Buildings ↗Agency page; no publication date shown

    Last reviewed by Bay Sale Ready: July 18, 2026. Information may have changed since our last review. Verify current requirements and status directly with the responsible agency before relying on it.

  • Time-of-Sale Energy Requirements for Multifamily and Commercial Buildings ↗Agency page; no publication date shown

    Last reviewed by Bay Sale Ready: July 18, 2026. Information may have changed since our last review. Verify current requirements and status directly with the responsible agency before relying on it.

  • BESO Administrative Regulations, Version 5.0 ↗November 1, 2025

    Last reviewed by Bay Sale Ready: July 18, 2026. Information may have changed since our last review. Verify current requirements and status directly with the responsible agency before relying on it.

Review the BESO Portal record, then ask BESO

Open the linked City portal and record only the building identifier, category, label, dates, and attachments shown there. Take those portal-reported fields to BESO for interpretation.

Bay Sale Ready boundary: A found result creates no Bay Sale Ready conclusion. An empty, error, or ambiguous result does not establish that a BESO record is absent or that a building has any particular status. Confirm search inputs, portal coverage, and record meaning with BESO.

Open the official record search ↗

Last reviewed by Bay Sale Ready: July 18, 2026. Information may have changed since our last review. Verify current requirements and status directly with the responsible agency before relying on it.

General order of questions

  1. Check the BESO portal record

    Bay Sale Ready summary of the linked City of Berkeley · BESO source: Start with the City's current building record before arranging an assessment or relying on an exemption, deferral, or prior score.

    Verify at official source: Time-of-Sale Energy Requirements for Small Residential Buildings ↗

    Last reviewed by Bay Sale Ready: July 18, 2026. Information may have changed since our last review. Verify current requirements and status directly with the responsible agency before relying on it.

  2. Use the correct building category

    Bay Sale Ready summary of the linked City of Berkeley · BESO source: Single-family homes and duplexes, three- and four-unit buildings, condominiums, and larger buildings can follow different City instructions and timelines.

    Verify at official source: Time-of-Sale Energy Requirements for Multifamily and Commercial Buildings ↗

    Last reviewed by Bay Sale Ready: July 18, 2026. Information may have changed since our last review. Verify current requirements and status directly with the responsible agency before relying on it.

  3. Confirm the City-approved path

    Bay Sale Ready summary of the linked City of Berkeley · BESO source: Review the current assessment and transfer instructions, then ask the BESO team or appropriate licensed professionals to confirm the path for the particular building and transaction.

    Verify at official source: Time-of-Sale Energy Requirements for Small Residential Buildings ↗

    Last reviewed by Bay Sale Ready: July 18, 2026. Information may have changed since our last review. Verify current requirements and status directly with the responsible agency before relying on it.

Important limits to keep in view

  • Source-linked caution from City of Berkeley · BESO: A Home Energy Score, an upgrade obligation, and a BESO Certificate of Compliance are related but distinct records and steps.

    Verify at the official source: BESO Administrative Regulations, Version 5.0 ↗

    Last reviewed by Bay Sale Ready: July 18, 2026. Information may have changed since our last review. Verify current requirements and status directly with the responsible agency before relying on it.

  • Source-linked caution from City of Berkeley · BESO: An individual condominium unit and the whole building may not follow the same BESO path.

    Verify at the official source: BESO Administrative Regulations, Version 5.0 ↗

    Last reviewed by Bay Sale Ready: July 18, 2026. Information may have changed since our last review. Verify current requirements and status directly with the responsible agency before relying on it.

  • Source-linked caution from City of Berkeley · BESO: Treat the City's BESO assessor information as a starting record for assessment work; verify any separate construction license independently.

    Verify at the official source: Time-of-Sale Energy Requirements for Small Residential Buildings ↗

    Last reviewed by Bay Sale Ready: July 18, 2026. Information may have changed since our last review. Verify current requirements and status directly with the responsible agency before relying on it.

This is an unofficial general question list, not legal advice, an application, certificate, disclosure, permit, legal deadline, or determination for a property or transaction. It may not cover every fact, exception, or rule change. Current governing law, live agency materials, and the responsible agency's decision control. Information may have changed since our last review. Verify current requirements and status directly with the responsible agency before relying on it.

Official instructions and records

These links come from the same reviewed source register used by the guide. The dataset was last reviewed by Bay Sale Ready on July 18, 2026; each card shows its own review date.

Last reviewed by Bay Sale Ready: July 18, 2026. Information may have changed since our last review. Verify current requirements and status directly with the responsible agency before relying on it.

City of Berkeley · BESO

Time-of-Sale Energy Requirements for Small Residential Buildings

Agency page; no publication date shown · Last reviewed by Bay Sale Ready July 18, 2026

Information may have changed since our last review. Verify current requirements and status directly with the responsible agency before relying on it.

Verify at the official source ↗
City of Berkeley · BESO

Time-of-Sale Energy Requirements for Multifamily and Commercial Buildings

Agency page; no publication date shown · Last reviewed by Bay Sale Ready July 18, 2026

Information may have changed since our last review. Verify current requirements and status directly with the responsible agency before relying on it.

Verify at the official source ↗
City of Berkeley · BESO

BESO Administrative Regulations, Version 5.0

November 1, 2025 · Last reviewed by Bay Sale Ready July 18, 2026

Information may have changed since our last review. Verify current requirements and status directly with the responsible agency before relying on it.

Verify at the official source ↗
City of Berkeley · BESO

BESO Compliance Guide for Small Residential Buildings

Updated April 2026 · Last reviewed by Bay Sale Ready July 18, 2026

Information may have changed since our last review. Verify current requirements and status directly with the responsible agency before relying on it.

Verify at the official source ↗

Frequently asked questions

Questions to verify, not legal conclusions

What is the first BESO check before listing?

Bay Sale Ready summary of the linked City of Berkeley · BESO source: Check the building's current BESO portal record and identify the City's correct building category. The small-residential and multifamily or commercial pages describe different paths.

Verify at the official source: City of Berkeley · BESO ↗

Last reviewed by Bay Sale Ready: July 18, 2026. Information may have changed since our last review. Verify current requirements and status directly with the responsible agency before relying on it.

Does a single-family home or duplex need a Home Energy Score before listing?

Bay Sale Ready summary of the linked City of Berkeley · BESO source: Berkeley states that, starting January 1, 2026, a seller of a single-family home or duplex must obtain a Home Energy Score before listing unless the City confirms an applicable exclusion or exemption from that assessment.

Verify at the official source: City of Berkeley · BESO ↗

Last reviewed by Bay Sale Ready: July 18, 2026. Information may have changed since our last review. Verify current requirements and status directly with the responsible agency before relying on it.

Does the same rule apply to an individual condominium unit?

Bay Sale Ready summary of the linked City of Berkeley · BESO source: The current BESO materials exclude an individual condominium unit from the one-to-four-unit time-of-sale path, but whole-building, HOA, mixed-use, or unusual ownership questions still need confirmation from the BESO team.

Verify at the official source: City of Berkeley · BESO ↗

Last reviewed by Bay Sale Ready: July 18, 2026. Information may have changed since our last review. Verify current requirements and status directly with the responsible agency before relying on it.

Can a seller defer an upgrade obligation to the buyer?

Bay Sale Ready summary of the linked City of Berkeley · BESO source: Berkeley describes a formal City-approved buyer-deferral path for some transactions. It requires the current City process and documents; this website does not determine eligibility or interpret the parties' agreement.

Verify at the official source: City of Berkeley · BESO ↗

Last reviewed by Bay Sale Ready: July 18, 2026. Information may have changed since our last review. Verify current requirements and status directly with the responsible agency before relying on it.

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Published coverage: Oakland, Berkeley, Hayward, San José, and San Francisco. This is selected coverage, not a complete inventory of local requirements.

Last reviewed by Bay Sale Ready: July 18, 2026. Information may have changed since our last review. Verify current requirements and status directly with the responsible agency before relying on it.

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