FEATURE STRUCTURAL TIMBER
Supporting Safe Timber Growth 1
Changes to Approved Document B could have profound implications for timber construction and the UK’s net zero targets. Andrew Orriss, Chief Executive of the Structural Timber Association (STA) provides some critical considerations. THE GOVERNMENT has been consulting on changes to Approved
11 metre thresholds
Document B, the fire safety guidance that sits alongside the
This review didn’t come from nowhere. The Grenfell Tower Inquiry
Building Regulations. The consultation was run jointly by the
Phase 2 report recommended that Approved Document B be kept
Building Safety Regulator, the Health and Safety Executive, and
under continuous review, and this set of changes is the latest step
the Ministry of Housing, Communities and Local Government.
in that process. The areas covered include cavity barriers, rules for
It applied to England and closed on 1 July, so it is no longer open
work on existing buildings, external wall systems, and a proposed
for responses.
height threshold above which buildings with combustible structural
Before getting into the detail, it is worth clearing up a point that keeps coming up in discussions about this consultation,
elements, including timber, would need to look beyond Approved Document B for their fire strategy.
including in the STA’s own response. Approved Document B is
That last point, the 11m threshold, is where most of the industry
not the regulation. It is statutory guidance on ways to meet the
attention has landed. The government’s reasoning is that the guidance
regulation. The Building Regulations set the legal requirements.
in its current form was written with reference to construction
Approved Document B – like the other Approved Documents – sets
methods and materials from decades ago, before combustible
out one way (not the only way) of satisfying them. That distinction
structure and insulation were used at the scale, they are today, and
matters, because much of the anxiety around this consultation
that taller or more complex buildings need a different approach.
comes from people reading the guidance as if it carries the force of
The STA does not disagree with the principle of a threshold. Its
law. It doesn’t. Alternative routes to compliance, using recognised
response supports the idea that there should be a point above which
standards such as BS 9991, BS 9999 or BS 7974, are equally valid.
Approved Document B guidance no longer applies on its own.
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Issue 53 July/August 2026
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