Currently, all new homes must come with a warranty from an accredited provider. About 80% have a 10-year warranty from the NHBC, an insurance company that says it inspects “every home” registered with them. During the first two years of the policy, the NHBC says the builder is responsible for fixing any defects which do not comply with its technical standards. During years three to 10, the NHBC provides direct insurance cover for damage caused by defects in specific areas of the home.

The NHBC paid out £84.8m in claims between 2016-17.

Campaign group HomeOwners Alliance says the current system does not allow for quality of workmanship and fittings. “Although work is meant to be inspected independently at key stages, the inspection regime is currently failing homebuyers,” says its chief executive Paula Higgins. Instead, she argues, there needs to be a higher body policing the sector.

“We’ve been calling for a new homes ombudsman for a long time now as we’re inundated with calls from our members about shoddy workmanship and flawed properties yet there is currently no one holding these developers to account,” she says. “These firms are under pressure to build and with a shortage of skills in the sector corners get cut.”

The revelation was made following a ‘ferocious’ blaze which broke out at Greenacres, described as a ‘prestigious development’ in Exeter.

Paul Frost, who lives in Trafalgar Road near to where the fire broke out, says he was the first to make the discovery when he used his building knowledge to inspect his own property.

Last week Persimmon Homes denied there was a problem with some of its properties.

But the housebuilder had already penned a letter to residents asking them to inspect their homes due to roof space cavity problems in another property.

A report, by the National House Building Council (NHBC), and shared with Devon Live, states the missing barriers at Mr Frost’s property posed an ‘imminent risk to health and safety’, and there was a breach of building regulations.

The developer has not confirmed how many properties so far have been identified as failing to meet required safety standards, despite direct questioning.

However, an indication of the extent of the problem has been provided by Paul, who has asked all residents to let him know the outcome of their inspections.

His says his findings so far have shown out of 18 homes he knows to have been inspected, 70 per cent are missing fire resistant cavity barriers.

He said: “It is horrific to imagine the impact on a family, never mind potential loss of life.

“Not only is the builder responsible for this horrific situation of missing fire barriers in so many homes, but the site managers, construction heads and managing director of, in this case Persimmon Homes South West, are also culpable because they are clearly not checking their homes properly as they are being built, or before they are sold.

“However, and perhaps in some ways even more serious, is the fact these homes have been signed off by a qualified building inspector, in this case employed by the NHBC, to be fully compliable with existing building regulations at the time of signing off. This just shocks and offends me and I feel a moral obligation to ensure all new homes are built and signed off to better standards than they are currently.”

The problem has emerged following major fire in Trafalgar Road, off Admiral Way and Topsham Road, back in April, which spread into the roof spaces of two of the adjoining properties.

Firefighters had to dig through cavity walls between properties to ensure the fire was fully out.

Last Wednesday, October 31, Persimmon Homes denied there is a problem with the properties which were passed by the National House Building Council (NHBC).

A spokesperson for Persimmon Homes South West said at the time: “There was a fire in a property on Trafalgar Road several months ago, but official reports from the landlord of the property indicate that it was caused by a cigarette being discarded recklessly.

“Under these circumstances the structure of the house cannot be implicated and it would be wrong to do so.”

However, on the same day Persimmon gave the response it is believed it sent a letter to 88 residents informing them it was carrying out voluntary checks within the Greenacres development due to safety concerns.

The letter said: “We are conducting a check of roof spaces on your development to make sure the roof space cavity has been installed correctly following a recent inspection within the development.

“We are offering this precautionary measure to you. Should you wish to take up that offer please contact us and we shall arrange for an inspection to be made, and any necessary remedial works to be carried out.”

This week Persimmon has accepted there is an ‘error’ with some of its properties.

A spokesperson for Persimmon Homes South West said: “Following engagement with a customer who had raised a complaint, an issue with the cavity closure installation was discovered. We rectified this within 24 hours of being notified.

“As a responsible construction firm we are taking immediate action to ensure this error has not been replicated and have therefore been contacting our customers directly. We are checking all properties within the phase of the development as a precaution.

“We have in place a checking process where both the contractor and site manager sign off the cavity closer check. Periodic checks are made by the contracts manager.

“These checks are in addition to the NHBC building inspector sign off of the superstructure.”

Persimmon did not answer a number of key questions posed by Devon Live including:

When was the initial compliant lodged?
How many homes are being inspected in the Greenacres development?
How many have been inspected so far, and of those, how many have failed for missing fire barriers?
Who assessed and passed the properties as compliant which have now since failed?
Will all Persimmon homes now be inspected?

Trafalgar Road resident Mr Frost, who has more than 30 years experience in the building industry, knew his home had failed, and the NHBC support the result.

He said: “I live at the opposite end of the road where the fire was which may have also had missing cavity inserts which by law it should have.

“It doesn’t matter if it’s missing inches or metres; your home, contents and, worst of all, lives, are more risk than they should ever be. This is probably one of the biggest building regulations you can have.

“I went to a semi-detached house at the far end of the development by Ikea. The house passed but the house attached to it failed!

“Their homes were built seven years ago where as mine is four years old showing it’s possibly an endemic problem in the building industry.

“If only one fails that is horrific. To imagine the impact on a family, never mind potential loss of life for anyone, but to find a current statistic like we have here is abhorrent.”

The alarming problem has prompted Mr Frost to launch a national campaign calling for Parliament to consider a new direction to encourage developers to build better quality homes.

He said: “I want to try to make this a national campaign of some of sorts, to at least help to reduce the possibility of loss of life.

“The way forward is to encourage better quality construction and certainly the installation of heat sensors in roof voids, as a minimum outcome of this horrific situation of risking peoples lives for what can only be seen as better profits.”

Like many other Persimmon Homes owners, it is not the first problem Mr Frost has experienced with his property.

He says he has had about 130 ‘snagging issues’ including faulty brickwork which will mean him having to move out while it is repaired.

Mr Frost, who set up a company called Snagaroo snagging inspections, due to all the problems he and his neighbours have had, said: “The number of issues we have had with our home has reached a point where Persimmon have agreed to rebuild our external facades, as well as conduct over £20,000 of work internally.

“That was before we reveal any issues with the timber frame or floor levels.

“And it’s not all over yet; We are forever seeing something else. The problem is quality control. Once they get that right there won’t be a problem.

“In fairness to Persimmon, as soon as my house was found to be missing fire resistant cavity barriers it was sorted out straight away, but it should have been built properly in the first place.”

Fellow Trafalgar Road resident Lydia Burge has also encountered many problems with her new build.

It was five years ago this month she moved in to the road and after having had 120 issues with the property she says she is still experiencing problems.

Her home is one of those which has found to have had the correct the fire barriers so passed the inspection.

She said: “I am afraid that myself and probably all my neighbours have never been happy with the standard of build and the response to problems were always a problem when we were within the guarantee period. I have yet to come across anyone who has purchased a Persimmon house that has been happy.”