Heading for a fall

One early may morning in 1968 a council tenant in Newham, east London, lit her cooker and a massive gas explosion ripped through the 18th floor of her tower block. The entire east side of the 23-storey block, constructed using the “large-panel system”, collapsed like a house of cards.

A faulty gas connection had caused the explosion; four people died and 17 were injured as a result.

Nearly 40 years later, the Ronan Point disaster is well known in housing departments up and down the land. But several councils have recently realised advice issued after the collapse has not been followed: another Ronan Point could still happen. And unless central government takes action, it will be left to social landlords themselves to make sure it doesn’t happen.

A public inquiry into the disaster was held in 1968. It was followed by regulations to safeguard multistorey buildings against collapse, and these rules were backed up by building regulations in 1970. After further research on Ronan Point, in 1987 construction research body BRE issued well-publicised updated guidance, recommending local authorities check the robustness of all LPS blocks more than four storeys high.

But no one has ever checked thoroughly across the country to see which local authorities have taken action. Nor are there any central records of how many such LPS blocks remain or who owns them. What is known is that LPS buildings continued to be built after the collapse of Ronan Point: the numbers built doubled between May and December 1968.

So what is the problem with LPS construction? LPS, which was used as a solution to the 1960s housing shortage, enables tower blocks to be built using unskilled labour by bolting together prefabricated concrete panels that then bear the weight of the building. The pre-1968 design left some, if not all, LPS blocks at risk of collapse when put under an unusual strain – such as a gas explosion. A report by the structural engineering consultancy Alan Conisbee and Associates, commissioned by Southwark council and published last month, said: “The original design of most LPS blocks meant that one explosion could result in many dwellings suffering.”

Ronan Point had other problems, too. When local architect Sam Webb examined Ronan Point independently in 1968, and again on behalf of local residents in 1987 before it was pulled down, he found that joints in the structure had been filled with newspaper and empty sacks rather than concrete. Walls that should have been resting on a bed of mortar were hanging on levelling bolts fastened to the load-bearing panels. The whole weight of the building was therefore resting on these bolts, and that weight cracked some of the panels.

Risk remains

Similar problems have been found in LPS buildings of the same age across the country, and more could still be discovered. Southwark commissioned its structural engineers’ report when it realised LPS blocks on its Aylesbury estate had never been checked. Last year Islington council, too, realised it had overlooked LPS blocks. Birmingham council found the same thing in 1999. Webb, who has advised Birmingham and Islington on LPS structures since 1987, estimates there could be thousands more unchecked flats across the country.

Last year, in a letter to Webb seen by Housing Today, housing minister Keith Hill admitted he had advised the ODPM of the “possibility” that some LPS blocks throughout the UK had not been checked for robustness in accordance with either the 1968 regulations or the 1987 BRE guidance.

Hill said: “Whilst one may argue that because these buildings have ‘stood the test of time’ they must have adequate structural integrity, few (if any) of them are likely to have been subject to any accidental event.” Webb wasn’t reassured. “I just think we have been extremely lucky,” he says. “With these buildings it’s a bit like walking on eggshells.”

If the risks are so clear, who should be taking action and what should they do? Webb says any housing association or council chief executive should make it a priority to find out if LPS blocks have been checked in line with the 1987 BRE guidance. They should also take into account last December’s building regulations, which tightened the rules on resilience for new homes. If LPS buildings haven’t been checked, you should call in structural engineers to do the work.

The landlord should review all the relevant documentation, such as planning approval: if approval for a LPS building was granted before the 1968 regulations came into force, the building will almost certainly be unsuitable for gas supply.

With little evidence that this has been done in the past, though, Webb is now calling for a new approach. “Local authorities need real money from central government to sort this inherited problem out,” he says.

You may need to take immediate action if you suspect a block is vulnerable: a gas explosion like the one that caused Ronan Point’s critical failure remains the number one risk for LPS buildings, according to the Aylesbury estate report. In March, Southwark reacted to its findings by cutting the gas supply to its five- and-six storey LPS blocks on the estate and and announced it would also carry out strengthening work.

But Southwark’s report suggested gas was also being kept in bottles in garages underneath the five-storey blocks on the estate. A minor fire that meets a gas cylinder could cause an explosion, and so Southwark says it will inform all residents that storing such cylinders breaks their tenancy agreements and will make spot checks.

It is hard to believe that Aylesbury is the only case of gas danger in LPS blocks: there are even stories that some councils and associations elsewhere in the country are giving Calor gas heaters to residents with heating problems.

Given that a disaster like Ronan Point could happen again, Webb says, further inaction is not an option. “I thought that once I had got the Ronan Point investigation done, that would be it. I never expected it to come back and haunt me. We should forget about who blames who and what they should have done. Get it right now. Councils owe it to the people who live in the blocks to do this.”