When to use this guide
- Planning a new building, extension or work affecting the thermal envelope
- Selecting insulation, glazing, heating or controls
- Preparing energy evidence, commissioning and handover information
What to check
Use these prompts with the responsible project team. Ticking a box does not certify compliance.
You can tick these prompts while reviewing the project.
Keep these records
- Energy assessment, assumptions and coordinated specifications
- Applicable installation, commissioning and test records
- Final compliance evidence and user information
Common mistakes
- Assuming the newest 2026 publication is already mandatory for every October 2026 project.
- Changing products or layouts without reviewing their effect on the coordinated energy design.
When to get specialist help
Use competent energy-assessment and design advice for the applicable route. Verify current dates on the official source before making a specification or promising compliance.
Scope and edition
Main landing retains 2021 edition with 2023 amendments. Separate 2026 Energy and greenhouse gas emissions volumes were published 24 March 2026 and corrected 8 September 2026. Main commencement is 24 March 2027; relevant HRB provisions 24 September 2027, with transitions. Use the edition applicable to the building, not simply the newest PDF. Published 2026 guidance is not automatically the standard already applicable in October 2026. Check notice/application dates, defined commencement and project/HRB transitional arrangements.
Energy performance and building services; dwellings and other buildings have separate volumes.
Use the official source to check the current text, amendments not yet incorporated, commencement and project-specific transition. A published future edition is not automatically the rule applying to your work.
Official sources
- GOV.UK — Approved Document LOfficial England guidance; check the applicable volume, edition and transition.https://www.gov.uk/government/publications/conservation-of-fuel-and-power-approved-document-l
- Approved Document L (2026)https://www.gov.uk/government/publications/approved-document-l-2026
- Future Homes and Buildings Standards: Building Circular 01/2026 letterhttps://www.gov.uk/government/publications/the-future-homes-and-buildings-standards-building-circular-012026/the-future-homes-and-buildings-standards-building-circular-012026-letter
Source links lead to external official websites. We provide original explanatory notes and do not reproduce paid standards.
About this library
Independent, plain-English reference notes by Saeed Azarshab. The library covers the 42 subjects listed here; it is not every law affecting construction, an official government publication or a project-specific compliance decision. Building Regulations, Approved Documents, workplace safety duties and planning permissions have different roles.
Editorial source review: . Check the current official text, commencement dates, outstanding amendments and transitional arrangements before relying on a requirement. Publication date is not necessarily the date a rule applies. A relevant competent professional or authority must resolve project-specific questions.
Sources and lawful reuse
Contains public sector information licensed under the Open Government Licence v3.0, except where otherwise stated. These are original practical summaries, with links to the official material. No government endorsement is implied. We do not host copies of proprietary BS, ISO or Eurocode standards, third-party diagrams or publisher layouts. Check each source’s rights notice before reuse.
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