Approved Document L Volume 1 was called Conservation of fuel and power for years, and a lot of what's written about boilers still uses that name. At the 2026 edition, the title changed to Energy and greenhouse gas emissions. Same volume, same place in the Building Regulations 2010 structure, just a different name on the cover.

Why this matters when you search

Search the old title and you may land on a page describing an earlier edition. That's not a broken link. It's the previous version, still sitting on GOV.UK, because it's still the one that applies to most jobs right now.

If your installer's quote uses the old title

Either name on a quote is fine. The 2026 edition doesn't take effect until 24 March 2027, so until then it's the 2021 edition (with its 2023 amendments) that governs a boiler replacement, whatever the quote calls it. What the quote should do is say which edition it's working to, so you can check it against the right document. If that's missing, ask your installer to add it.

You can read what changed between the two editions, including this title change, on the page covering what changed in the 2026 edition of Approved Document L, and check which edition applies to your own job on which edition applies to my job.

If your quote uses either name, that's fine: until 24 March 2027 the rules that apply are the 2021 edition's, whatever Volume 1 is called on the page in front of you.

A quote that names Volume 1 by its old title isn't wrong on its own. Installers often work from documents they downloaded some time ago, or from templates that haven't caught up with a rename. The title on the page tells you something about when the document was written.

Why the old name is still around

Volume 1 of Approved Document L was called 'Conservation of Fuel and Power' before the 2026 edition. It's now titled 'Energy and Greenhouse Gas Emissions'. That's one reason the old name keeps turning up in quotes, invoices and installer paperwork: anyone searching the old phrase can still land on a page describing the earlier document.

Seeing the old title on a quote doesn't tell you which edition applies, and neither does the new one on its own. Until 24 March 2027 the 2021 edition (with its 2023 amendments) is the one in force, whichever title your installer happens to have written down. Earlier editions carry on applying to work that started under them, so the date your job began is what decides it.

What to check next

• Ask the installer which edition the quote is working to, by year.
• Work out which edition governs your job using the dates that decide it, set out on Which Edition of Approved Document L Applies to My Job.
• If the edition matters to what's included in the quote, compare the two versions on What Changed in the 2026 Edition of Approved Document L.

None of this means the old title is a sign of a poor quote. It's a reason to ask one follow-up question, and the answer is a date.