Diales Compendium Issue 3 - Flipbook - Page 22
Part B, or
Approved Part B?
That is the
question.
Ambiguities in the statutory
fire safety Building
Regulations Part B and
the practical guidance of
Approved Document B
Rob Foster and Ben Chamberlain
Diales Associate Director and Diales Technical Expert
The fire safety requirements of the Building Regulations are
under ever closer scrutiny, as construction disputes relating
to the flammability of external wall cladding and insulation,
on high-rise residential buildings, continue to arise following
the Grenfell Tower fire in 2017. But should designers bear
liability where such products were specified and installed?
In England and Wales, the Building Regulations are approved
by the Secretary of State pursuant to the Building Act
1984. Within the Building Regulations 2010, the fire safety
requirements were described at Schedule 1, Part B. Of
particular relevance to insulation in external walls was
section B3.(4), which required that: “The building shall be
designed and constructed so that unseen spread of fire and
smoke within concealed spaces in its structure and fabric is
inhibited.” Additionally, section B4.(1) related to external fire
spread and required that: “The external walls of the building
shall adequately resist the spread of fire over the walls and
from one building to another, having regard to the use and
position of the building.” Both statutory requirements had
remained unchanged since 1985.
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The government also issues practical guidance about how
building design and construction may meet the statutory
requirements by way of a series of Approved Documents. This
guidance is updated periodically. At the time of the Grenfell
Tower refurbishment, the relevant fire safety publication for
high-rise residential developments was ‘Approved Document
B, Volume 2 – Buildings other than dwellinghouses, 2006
edition incorporating 2007 and 2010 amendments’ (‘ADB’).
Although amendments were made to ADB in 2013, the
guidance relevant to insulation and cladding, at sections 12.5
– 12.9, remained unaltered. Changes were also made to ADB
in 2018, 2019, and 2020. However, current claims pertaining
to external wall insulation and cladding tend to relate to
projects begun under ADB 2010 (or earlier revisions). As
such, that is our focus here.
Arguably, there were ambiguities in sections 12.5 – 12.9 of
ADB, which we shall examine below. There is also a question
mark regarding the extent that designers can rely on the
Approved Documents to discharge the statutory obligations
of Schedule 1, Part B, given that the recently produced (July
2020) ‘Manual to the Building Regulations, A code of practice
for use in England’, states: