A pair of internationally renowned architects have been threatened with enforcement action by the council over alleged planning breaches.

The couple - whose work has been featured in Vogue and Harper’s Bazaar – are accused by Camden Council of demolishing parts of their Grade II* listed building in Frognal, Hampstead, and digging foundations which do not match their original proposal.

In a report, the council wrote: “It is regrettable that a significant amount of unauthorised demolition in a highly graded listed building has been carried out without permission and approval sought retrospectively.

"The applicants are extremely fortunate that they have been able to demonstrate that the majority of their works harmed only non-historic fabric to a sufficient level of proof that enforcement action is not considered expedient."

But, it continued, the cumulative size of an unauthorised extension "would result in harm to the significance of the listed building."

Chief planning officer Daniel Pope wrote to them on May 17, saying the borough solicitor had been instructed to issue an enforcement notice.

The couple said they had ceased all works in January and were working with the council to find a solution.

Who are they?

Benjamin Eayrs – known professionally as Merlin – and his wife Zoe Chan Eayrs are famous for moving into properties, turning them into “bespoke” homes and selling them on.

Past projects have been in Spitalfields, Shoreditch and Islington.

“As we only make one home at a time, we literally live and breathe each home for at least two years,” their website states.

But in 2018, the New York Times reported that they would renovate a property in Hampstead as a “permanent residence”.

According to Land Registry documents, they purchased the former home of sculptor Sir Anthony Caro – in the Hampstead Conservation Area – for £4.1million in 2017.

The council granted permission in 2019 for what it called “modest” extensions above and below ground.

It said the plans would provide “an overall heritage benefit” by partially reinstating original features.

What’s the problem?

According to Camden Council, the couple carried out unauthorised works.

Documents say the extension the couple have begun works on is larger than the one for which they were granted planning permission.

Ham & High: A planning notice displayed outside the home announced plans to change 'footprint or rear extensions at ground and lower ground floor level'.A planning notice displayed outside the home announced plans to change 'footprint or rear extensions at ground and lower ground floor level'. (Image: Archant)

The council said the above-ground alterations would “significantly increase” the visual impact on neighbours.

The below ground expansion "would involve additional excavation and the creation of an additional room and two bathrooms", its report added.

The council engaged engineers Campbell Reith, who said the expanded basement could cause “stability issues”.

Council officers concluded: “The current proposals would change the details, proportions and scale of the scheme to a degree that the benefits are no longer in balance with the harms.”

The defence

The couple said in a report to the council that after the initial permission was granted, they asked structural engineers to ensure the works “avoided harm” to a tree.

They said the engineer had recommended the creation of a “subterranean void” as a solution.

The report said the couple had "sought to make use of" that void.

The documents said it was also “necessary” to reduce the width of the ground floor extension, so they had extended the length to “mitigate”.

They denied it would adversely impact neighbours.

The council

Camden Council said in a statement: “When it became apparent that unauthorised works had taken place on site, an enforcement investigation was opened and retrospective applications were submitted for amendments to the scheme.

“The council refused planning permission and listed building consent for those amendments and warned the applicant of formal enforcement action.”

In a statement to the Ham&High, the couple said: "We are committed to preserving the historic elements of our family home, which is a listed building, and to ensuring its long-term safety and durability.

"We have spent years researching the listed building and have designed the plans with the house's history and features in mind.

"The plans incorporate many heritage benefits which reinstate the original features of the listed building.

"We are working to submit revised plans that address concerns raised in the council's report."