The winds of change?

The Department for Levelling Up, Housing and Communities (DLUHC) has published and endorsed important guidance from BRAC which reinforces a fundamental principle underpinning the regulation of building safety in England. In so doing, the powers that approvers have to challenge designers have been re-stated and re-enforced and in so doing fire safety designers should be empowered to challenge clients and other design team members when they set out design solutions that, by their evaluation, are necessary to secure reasonable standards of safety.

Conversely, if you are a fire safety designer, you won't be able to hide behind "well the AD B says it is OK", not that you should have been anyway!

I consider this is a very welcome clarification and perhaps the most profound and critical update to guidance in the post-Grenfell era, especially when read in conjunction with the new FAQs 17 and 18.

The question for BRAC and the resulting clarification from DLUHC arose from the single stair debate. I remain puzzled as to why debating the number of stairs for future buildings has become a pivotal issue, rather than what I would consider the more relevant question of fire safety in legacy buildings (ie those pre-2006 guidance) and other more specific questions such as “Why don’t we have sprinklers in legacy tall buildings?” and “Why don’t we require an upgrading of firefighting and lift evac provisions in legacy buildings?” or “Why do we allow legacy smoke control designs that don’t work to be retained in legacy buildings?”

However, as the joint timing of the FAQs and the DLUHC clarification shows, this is not just about the number of stairs, but relates wholesale to the scope of reliance on the AD B. To some extent this also impacts guidance such as BS 9991, but that already cautions against blind adoption of guidance without proper substantiation as does certain critical standards such as those relating to sprinklers. Given the overly prescriptive adoption of the AD B by too many (by no means all) designers or the willingness of too many (by no means all) approvers to sanction designs purely on the basis of the AD B, it is around that document that the clarification has the most impact. Although, designers should also reflect on whether quoting equivalence against an AD B based design is an appropriate means of demonstrating adequacy (which has a knock on effect to guidance such as the SCA Guidance on Smoke Control to Common Escape Routes). Further clarifications from other bodies may well be necessary.

Of course, the clarification cuts both ways, so those that have sought to rely on the AD B as defining regulatory compliance should be challenged. This is of course a perspective often preferred in civil claims because it provides the convenience of binary arguments much adored by one side in any such case. That topic perhaps needs an article of its own.

Returning to the matter of design, to be clear, it’s not that the AD B is wrong, it’s that it is not always right. Designers should be checking whether the AD B is right and justifying its use (or an alternative), not falling back on it as a default or relying on it prescriptively.

For some practitioners, the clarification will leave them perplexed and frustrated that terms like "very tall" and "very large" are not defined. I have sympathy for that perspective, after all the philosophical aspects of safety regimes are all well and good, but some poor sod has to apply them at the sharp end. The next step by DLUHC (arguably perhaps should have been a prior step) is to set out additional statutory guidance relating to very tall, very large and complex buildings. This would take the form of tolerability targets for taller residential buildings (and other higher consequence buildings) and set out what adequately safe should mean in terms of other practical metrics. This is not a high falutin aspirational concept, it exists already within other Building Control regimes such as C/VM2 in New Zealand. That guidance arose when NZ uncovered cracks in their Building Control process following disasters that wreaked havoc upon the confidence in building safety, a situation remarkably familiar in outcome to the post-Grenfell era in the UK. However, it seems to have taken more than five years of fumbling around by various committees and reviews before (independent of these other well meaning yet oft doomed processes) we now start to see some recognition of a fundamental underlying problem in the application of the current regulatory system in England. I say England, but of course this applies to the rest of the UK (and those that gaze upon the UK), even if they think it doesn't.

Dame Hackitt nailed it first time of course by noting that higher risk residential buildings (do we all remember when HR in HRRB maintained the focus on higher RISK not high RISE) needed special consideration. The response to that has been to seek new primary legislation which has engorged the category of future relevant buildings (perhaps to the point where a new safety regulator may find itself swamped), taken far too long to enact, become a political football and resulted in a situation where it will take many more years for the necessary secondary legislation to emerge. At the same time, that process will essentially leave legacy building provisions untouched (albeit with more oversight of the legacy dysfunctional designs) and has not (and could not credibly have) touched the fundamental legal framework that underpins property wealth which ultimately creates a bar on how and where responsibility for safety is set. Perhaps if we'd considered an alternative approach to Hackitt's findings, not just reinforcing the non-prescriptive nature of the AD B but clarifying the scope of the AD B sooner, we'd already have in place the necessary guidance for out-of-scope buildings (ie those which are in-scope of new legislation) and be moving forward within a modified version of the pre-existing framework. Then perhaps we might have turned to the longer term actions of primary legislation to fundamentally change the regulatory system (if it became apparent that such change was needed). I anticipate that might have kept the focus in the right place for new build and provided capacity to address legacy challenges. Personally, I think that could have been a more sanguine response and left us in a better place sooner.

But, more optimistically, with these new clarifications now in place, perhaps we are on the road towards a more considered approach for higher risk buildings. A chink of light at the cave entrance? Of course, stepping out of the cave brings its own new challenges and that is why follow-up guidance on what to do when you place the AD B back into its rightful place as just another piece of guidance, is essential. A new testament is needed as the old one can no longer be relied upon as an all encompassing mantra.

As for the prescient question of what is "very tall"? My understanding is that this language exists because there are specific structural fire aspects at height. However, my personal preference is to use the term “complex” buildings and allow that to encompass tall (as against just high rise) buildings as well as those using modern construction methods (much of the AD B remains rooted in the post war building studies). These are semantics, but clarification is necessary I feel.

For example, confusing as it may be, to me “tall” should be thought of not just in terms of absolute height but as a class of buildings where height and other complexity factors combine. Effectively “tall” is a hazard and consequence category where height is the primary hazard / consequence driver. However, using words that have a common meaning in a specific technical sense is bound to bring problems, so again, I prefer to fall back on "complex" as a definition because there is less scope for confusion.

As a pragmatic approach, for residential buildings, I’d start questioning the AD B’s relevance at say 30m because of the implications on smoke control from that height as well as common external firefighting equipment limitations. By 45m you are in clear territory where the AD B guidance (and any other standard design approach) needs validation. Although, it can be argued that the paucity of solutions for self-egress of persons who cannot use stairs makes the AD B questionable in some aspects from about 18 m.

In closing, would suggest that the construction, design and approval industry may wish to brace itself for some other aspects that could (and should) arise from the trajectory that this clarification has nudged us onto. When designers and approvers start to look at the justification of designs for tall residential buildings it will not be (well should not be) simply a matter of “there’s two stairs, that is OK” because the designer will have to justify why two stairs and not three or one provides adequacy. They’ll have to explain what scenarios create a need for a second stair and they ought to drop the notion that a second stair is needed for the vague principle of “just in case” without saying what case it is needed for. If we do not insist upon this, then some very bad two staircase designs will emerge. Evidence and demonstration of adequacy is what the clarification demands. So designers should be asked; why, if they know the scenario where extra provisions becomes essential exists, haven't they mitigated that scenario more in a more fundamental way instead?

The same principle will apply to changes in evacuation protocols, and unevidenced solutions applied to patch over the concerns arising from modern construction methods. As a result, we should be prepared for the dismay, outrage and relief that may well emerge if due process reinforces certain, current design principles as adequately safe.

It is unpopular to suggest or even speculate that there may already be a body of knowledge that knows how to design buildings safely already, and yet buildings are being designed every day, and perhaps some of them, even some using current guidance, may turn out to be adequately safe. That will of course depend upon defining what adequacy really means, hence the importance of developing statutory guidance on this matter with due haste because what we mean by adequacy is a socio-political construct, to be determined by the legislature with due regard to the societal impact of such definitions.

You can read the BRAC correspondence and clarification letter from DLUHC here:

The FAQs relating to modern construction methods can be found here:

And if you are interested in how NZ responded with C/VM2 a decade ago, you can find that here: