Paragraph 10.12 cites a sub-paragraph letter the regulation does not carry

Paragraph 10.12 of Approved Document B Volume 1 refers to the definition of a specified attachment and points the reader to a sub-paragraph of regulation 2(6) of the Building Regulations 2010 (SI 2010/2214). The sub-paragraph letter it names is not the one that regulation currently carries for that definition.

Where the definition actually sits

In the current England text, a specified attachment is defined at regulation 2(6)(c) of SI 2010/2214. A reader who follows paragraph 10.12's citation to legislation.gov.uk and checks the lettering against the live text will find that the letter does not land on that definition.

Why the error is easy to miss

Regulation 2(6) is lettered differently in the England and Wales texts of the Building Regulations 2010. A sub-paragraph letter that is correct for one text is not automatically correct for the other, so a reader who checks only one version can read a faulty citation as sound, or a sound one as faulty, depending on which text they happen to have open.

What it changes for a specifier

The miscitation does not alter what regulation 2(6)(c) requires, and it does not change what counts as a specified attachment. It does mean that quoting paragraph 10.12 letter and all, without checking it against the current regulation, hands a client or a building control body a reference that will not resolve. Where you cite this provision in correspondence or a specification, cite regulation 2(6)(c) of SI 2010/2214 itself.

Regulation 2(6) of SI 2010/2214 sets out the definitions that the Building Regulations rely on, including the one for a specified attachment. The England text and the Wales text do not number these definitions in the same order: a term sitting at one sub-paragraph letter in one text sits at a different letter in the other.

A sub-paragraph letter on its own does not identify a definition. It identifies a position in a list, and the two lists are not the same list. Check a citation against only the England text, or only the Wales text, and a letter can appear to line up correctly while pointing at a different definition from the one the citation actually means.

Why checking one text is not enough

A citation that gives a regulation number and a sub-paragraph letter, without naming the term that letter introduces, cannot be verified against a single text. You have to open both the England and the Wales versions on legislation.gov.uk, read the defined term printed at that letter in each, and confirm which jurisdiction's text the citation is drawing on. Skip that step and a miscitation carries forward unnoticed, because the letter looks right and gives no reason to look again.

What to ask for

Where a document cites regulation 2(6) by letter alone, ask the author which text the letter refers to and have them name the defined term it introduces. A letter without its term is a position you have to guess at.

A miscitation inside Approved Document B does not change what regulation 2(6) of SI 2010/2214 actually requires. The regulation stands as written whether or not the guidance paragraph that points to it names the right sub-paragraph letter. What changes is whether you can use that paragraph as a shortcut back to the regulation's own wording.

Why the citation still matters

Specifiers quote Approved Document B paragraphs in specifications and in correspondence with building control because the paragraph is meant to lead back to the regulation behind it. Where the paragraph names a sub-paragraph letter the regulation does not carry for that definition, anyone who follows it lands on the wrong defined term. The regulation itself has not moved. The route the guidance offers to it has.

What to check before you quote it

• Read the regulation at the sub-paragraph it actually sits at.
• Check both the England and the Wales texts before you quote a sub-paragraph letter, because the two texts letter the same definitions differently.
• Where paragraph 10.12 is cited in a specification or a letter to building control, cite the regulation separately.

None of this changes which build-up satisfies the regulation. It changes which document you hand over when building control asks you to show your working.