“A disaster waiting to happen,” is how the architect and fire expert Sam Webb describes hundreds of tower blocks across the UK, after the fire at Grenfell Tower in Kensington that has left at least six people dead. “We are still wrapping postwar high-rise buildings in highly flammable materials and leaving them without sprinkler systems installed, then being surprised when they burn down.”

Webb surveyed hundreds of residential tower blocks across the country in the early 1990s and presented a damning report to the Home Office, which revealed that more than half of the buildings didn’t meet basic fire safety standards. He said: “We discovered a widespread breach of safety, but we were simply told nothing could be done because it would ‘make too many people homeless’.

“I really don’t think the building industry understands how fire behaves in buildings and how dangerous it can be. The government’s mania for deregulation means our current safety standards just aren’t good enough.”

Webb advised the legal team for the families in the case of the last major tower block blaze in London, in July 2009, when a fire raged through Lakanal House, a 14-storey block built in 1958 in Camberwell, south-east London. Six people were killed, among them two children and a baby, when a fire caused by a faulty television in a ninth-floor home gutted the building.

An inquest into the deaths found the fire spread unexpectedly fast, both laterally and vertically, trapping people in their homes, with the exterior cladding panels burning through in just four and a half minutes. As with Grenfell Tower, the official advice was for people to remain in their homes in the event of a blaze. The inquest concluded that years of botched renovations had removed fire-stopping material between flats and communal corridors, allowing a blaze to spread, and that the problem was not picked up in safety inspections carried out by Southwark council. The council was investigated over possible corporate manslaughter charges, but eventually fined £570,000 under fire safety laws.

Fire safety in UK buildings is governed by part B of the Building Regulations, a document that has not been subject to an in-depth review since 2006 (by contrast, other parts are reviewed every two years). A 2015 survey by the Fire Sector Federation, a forum for fire and rescue organisations, found that 92% of its members believed the regulations were “long overdue an overhaul”, claiming that they do not reflect today’s design and construction methods and that research underpinning the guidance is out of date. The coroner in the Lakanal House case also called for a review of part B, as the evidence pointed to a risk of further deaths in the future unless changes were made, with about 4,000 tower blocks in the UK remaining subject to outdated regulations.

Arnold Tarling, a chartered surveyor at Hindwoods and a fire safety expert, says the elephant in the room is the flammability of insulation panels that are being used to clad postwar buildings to bring them up to date with today’s thermal standards. A recent £8.7m refurbishment of Grenfell Tower saw the building clad with “ACM cassette rainscreen” panels, an aluminium composite material covering insulation panels, which could have caused the fire to spread more quickly up the facade of the tower.

“The issue is that, under building regulations, only the surface of the cladding has to be fire-proofed to class 0, which is about surface spread,” says Tarling. “The stuff behind it doesn’t, and it’s this which has burned.” He says he recently inspected a new-build eight storey block in south-east London where there was no fire protection in the external cavity walls. “The insulation behind the external cladding is flammable polyurethane. I know because I took a chunk out and burned it.”

Scott Sanderson, director at PRP Architects, has worked on the refurbishment of several postwar high-rise housing estates, including recently Bow Cross in Tower Hamlets, east London, where three 25-storey 1960s tower blocks were over-clad with insulated render.

“The issue is about compartmentalisation,” he says. “Whatever cladding system you use, you have to incorporate fire stops at the line of each floorplate and every party wall around a dwelling to prevent fire from spreading up the facade. The current regulations are robust enough, but they have to be properly followed, and the architects drawings properly executed on site.”

Dr Jim Glocking, technical director of the Fire Protection Association (FPA), thinks our standards need a fundamental overhaul. He says he has been campaigning for years to see fire safety standards improved, to no avail.

“We have been very concerned about the introduction of highly combustible products into buildings,” he says. “They are often being introduced on the back of the sustainability agenda, but it’s sometimes being done recklessly without due consideration to the consequences. It’s not uncommon for buildings to have blocks of polystyrene up to 30cm deep on the outside, which is an extraordinary quantity of combustible material to be sticking on to a building. There are often ventilation voids between the rainscreen cladding and the insulation to prevent damp, but this also increases the spread of flames.”

He says UK fire regulations are unique in focusing on simply evacuating people before the building falls down, but not on properly tackling the ingress of fire from outside. “Our regulations are generally very good at keeping people safe,” he says, “but they work on a presumption that fires start inside buildings and that the method for protecting people is to ensure that it stays in the room of origin, doesn’t get to any neighbouring rooms, and certainly doesn’t get to any floors above. But they do not cater for fires ingressing into the building from outside or spreading to the external cladding, which appears to be what happened at Grenfell Tower.”

“We really are forgetting the lessons of the past,” he adds. “I think the inexcusable element here is that with cladding or insulation there are choices. There will be a perfectly good non-combustible choice that can be made, but somebody is not making those calls. It’s a tragedy that long-awaited changes to regulations usually only happen after significant loss of life.”