As all the clause numbers you committed to memory change, Andrew Mellor decodes the new guidance and what it will mean for architects

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The consultation document “Building a Safer Future – Proposals for reform of the building safety regulatory system” states that the government will be reviewing the Approved Documents B (fire safety), L (conservation of fuel and power), F (ventilation) and M (access to and use of buildings) within the next 12 months.

In fact, the next version of Approved Document B was published earlier this month. It aims to clarify the misunderstandings that came about as a result of the wording and diagrams in the previous versions. It does also include the combustible materials ban guidance which was published in December 2018. There are still two volumes within the new version, but now all residential buildings (houses and flats) are covered by volume 1 and non-residential buildings by volume 2.

As a result the section and clause numbers you will all be familiar with have changed, so it will take some time to find the relevant sections in the new documents. A number of diagrams have been redrawn, relocated or in some cases withdrawn (the old diagram 40 relating to external wall surfaces seems to have gone). There are changes to wording too: the term “filler” which was much discussed in the wake of the Grenfell tragedy has been clarified as a core material.

On first review the documents look to be more contemporary, clearer and more succinct but the proof will be in their use. We must all, however, remember that the Approved Documents are only guidance and that it is the Building Regulations that must be met.

What is absolutely clear is that we are entering a period of significant regulatory upgrades

For those considering providing the new principal designer service under the proposed Building a Safer Future regime, this will be an important consideration. The principal designer (high-risk residential building, not CDM) will have to co-sign with the principal contractor to state that to the best of their knowledge the building complies with the Building Regulations. We wait to hear what professional indemnity insurers have to say about that and what it means for insurance premiums for those conducting this service.

Furthermore, we can expect a wholly revised Approved Document B in the future which will incorporate new guidance, but I expect its publication is two years away.

Approved Document L is being reviewed to consider current and forthcoming legislation requirements related to carbon emissions. With buildings being made more air-tight through improved air permeability requirements, indoor air quality becomes more and more of a concern in relation to the health and wellbeing of those who occupy the buildings. The ventilation guidance in Approved Document F is, I assume, therefore being reviewed to ensure that it provides the correct guidance on the required number of air changes etc. This work follows on from wide-scale testing by MHCLG of ventilation systems and air quality levels in occupied homes.

MHCLG commissioned my practice, PRP, to carry out research into whether the requirements of Part C and the guidance in Approved Document C adequately protect buildings and those who use them from the harmful effects of moisture and condensation. The findings reports of this extensive desktop research project have very recently been published on the government website. This may suggest that a revised Approved Document C will be issued in due course. The work related to new and existing buildings and in particular to the superstructure. It considered two key aspects:

  • to verify the robustness of the guidance presented in Approved Document C for new buildings in the light of proposed changes to Part L and to identify gaps in the current guidance;
  • to develop a set of relevant guidance for situations where insulation is retrofitted to existing buildings.

The work was instructed because of concerns related to the potential for surface or interstitial condensation in buildings as a result of poor detailing or construction and the potential impact this may have for promoting mould growth and the consequential impact on the health of occupants.

What is absolutely clear is that we are entering a period of significant regulatory upgrades. This means we are all going to have to be alert in order to anticipate the likely effect of these changes on the design, procurement and construction delivery of the projects we are involved with in advance of the changes coming into effect.

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