In the emotionally raw aftermath of such an enormous tragedy as the fire last week at Grenfell Tower in London, there is naturally a search for answers and a need to ensure thorough accountability.
However, this has resulted in a focus in the media on the cladding and whether or not it was ”banned”. Even chancellor Philip Hammond has waded into the debate saying it is his ”understanding” that it was for certain uses.
This focus raises a challenge for engineers in how they communicate the complex decision making process that ultimately leads to a building being deemed fire safe or not. The difference between regulations and guidance can cause confusion, particularly when many of the questions being raised have no straightforward answers.
“There’s a fundamental confusion in the public domain between the regulations and the guidance to those regulations,” says chartered fire engineer and Council on Tall Buildings and Urban Habitat fellow Simon Lay. “The regulations are the Building Regulations and the statutory guidance to those regulations is the Approved Document B - and they’re not the same thing.”
This is important as it means compliance of the regulations does not necessarily mean compliance with the guidance. It is here where some confusion may arise.
“It’s quite upsetting when you see professional design industry say, the regulations ban this or they prohibit this, when they don’t,” says Lay. “They may well go against the guidance for the regulations, but they don’t specifically ban things, that’s not the way our regulations are written.”
In the UK, fire design is based on a performance standard and it is done this way for good reason says Lay. The opposite, a prescriptive based regulation, can lead to an ‘embedded presumption’ that if the building is designed as it says, it is safe.
“The power we have with a performance based approach is that you can look at it holistically, you can look at the package of measures, you don’t have a presumption of safety,” he says.
“You tend to find with prescriptive regulations people find a way of interpreting the regulations to make it safe, you get these fudges creeping in.”
With each building being individual, the approach is aimed at giving designers and approvers power to challenge the guidance, based on a typical building, should it not be appropriate.
When it comes to what has been portrayed in the media about the cladding, he says the cladding cannot simply be looked at in isolation. The thin line making up an external façade on many drawings is actually a complex build-up with many different parts to it.
“Unless you know the specific details of what’s been put on the building, how it’s been installed and how it’s been maintained, you can’t know whether that cladding system was acceptable,” he says.
He also says it is too early to hone in on specific areas the investigation will need to focus on, doing so could mean critical details are overlooked.
“Beyond the design, construction and operation of the building, consideration will also likely be given to the approvals process, fire and rescue methodologies and the assumptions made about how buildings are used,” he says.
“Speculation at such an early stage could well lead to critical details being overlooked.”
It may be some time before the investigation reaches its conclusion and what repercussions this will have for the industry.
Grenfell Tower fire | Confusion and a need for answers