A Wandsworth home could be destroyed simply because planners say that its roof is 20cm too high.

Despite London’s housing crisis, planning officers at Wandsworth Borough Council may order the flat, off St. Ann’s Hill, to be demolished if planning permission is refused later this month.

The top-floor flat in Denton Street is a one-off development by two of the building’s residents who then sold it in good faith to a young couple. The flat had been completed, with planning permission, on top of the Edwardian two-storey block of flats in 2016.

Council planners subsequently alleged that the building works had left the roof 20cm higher than the approved plans. They warned that the roof would have to be lowered which would mean that the flat would have be demolished - any reduction in the height of the roof would reduce the ceiling height to a point where it would be uninhabitable.

But a spokesman said Wandsworth Council strongly disputed whether the flat would need to be demolished, pointing out that the finished flat did not conform with the planning permission previously granted.

John Banbury, one of the two residents who developed the flat and who is representing the remaining leaseholders, disputed the height difference.

John said: “This is a typical David and Goliath story. The Council has granted permission for massive schemes by big developers such as Battersea Reach that will dramatically change the area forever.

“But at the same time, it is making life very difficult for homeowners and smaller, one-off developers who are trying to sensitively evolve the existing housing stock.”

On the recommendation of a council planning officer, he has resubmitted the planning application for approval. John is now hoping that Councillors will approve the application when it goes to planning committee on August 22.

If Councillors refuse the application, the flat’s new owners could face the heartbreak of losing their home and certain financial catastrophe.

In a bid to save the home, John has now contacted local Members Cllrs Sweet, O’Broin and Mayor Cllr Piers McCausland.

John added: “I firmly believe that the works to the building do not adversely affect the character of the area. But even if they had, this would not have been sufficiently harmful to warrant the demolition of a perfectly good home and to make the owners homeless.”

The draft London Plan has set as its target 65,000 new homes per year over the next 10 years to tackle the capital’s acute housing shortage. In other parts of London such as Primrose Hill, roof extensions are actively encouraged as a solution to the housing shortage.

In addition, revised national planning guidance published last month, the National Planning Policy Framework, provides backing for upward extensions.

A Wandsworth Council spokesman said: “This is an unlawfully constructed roof extension that exceeds the planning permission that this developer asked for and was subsequently given. It is of course highly regrettable that some developers do not comply with the permissions they’ve applied for and been granted and that they then go on to sell the property to an innocent third party when the works they’ve carried out are not lawful.

“The homes in this terraced street are of a uniform design so it is important that any changes do not harm the character and appearance of the street and impact negatively on neighbouring properties. A retrospective planning application for these works will be considered by our planning committee in the coming days and all the evidence in relation to this case will be very carefully and impartially considered.”