AN EIGHT-bedroom mega-mansion could be built on the site of Athlone House overlooking Hampstead Heath, the New Journal can reveal.

 

Planning documents filed at the Town Hall show the mystery owners – whose identify has been kept secret since they bought the property nine years ago – want to demolish the Victorian pile and replace it with a huge new home costing up to £80m to build.  

 

The new mansion in Hampstead Lane, which includes roof terraces with views across London, is designed by renowned neo-classicist architect Robert Adam, known as Prince Charles’s favourite designer. 

 

It has four corner towers and a ground-floor ballroom, complete with terrace overlooking Kenwood. Gardens boast two new ponds, a grass-surfaced tennis court, ornate orchard and a formal, Italianate-style area. 

Plans show a basement swimming pool with a ground-floor viewing gallery overlooking it. An underground car park would include a car lift. 

 

The previous owners were allowed to build luxury flats in the gardens after signing a legally-binding agree­ment to restore Athlone House. 

 

Now, a coalit­ion of influential civic groups, including the Highgate Society, the Heath and Hampstead Society, Highgate Conservation Area Advisory Committee and Athlone House Working Group are objecting to the new plans.

 

They say they will take legal action against the current developer to stop building work and make sure they stick to the original deal. 

 

The Highgate Society’s Michael Hammerson said: “We are completely appalled by the approach they are taking. It is not as if they were forced into an unaffordable Section 106 agreement to restore the home. They bought the property knowing full well about it, and it was part of a deal that gave permission to build extremely lucrative flats in the grounds. 

 

“Their behaviour is disgraceful. The cost of restoring Athlone House is irrelevant. We will be running a vigorous campaign to stop this and it is essential people write to the Town Hall in large numbers to object.”

 

Athlone House, built in the 1860s by industrialist Edward Brooke, was used as a convalescent home for soldiers during World War I and became a top-secret training headquarters for RAF pilots during the Second World War. 

 

It was then handed to the NHS and for decades offered beds with beautiful views for older people. It was finally sold for £7m. 

 

In 2004, the new owners applied to build flats in the gardens – and were given permission after agreeing to restore Athlone House. The flats were completed and sold for millions, but the house remains empty and is slowly crumbling. 

 

Property lawyer David Cooper, who represents the mystery owners, said they did not feel bound by agreements made previously regarding Athlone House restoration. 

 

The application includes a report from construction costs firm Selway Joyce claiming that to restore Athlone House would cost  £20m. 

 

Mr Cooper said: “They feel the Section 106 has no serious relevance any more to the project they are proposing. It was not written in cement. Not many people have got £20m to spend on restoring it and the few who do would never want to.”

 

The project will cost “north of £40m when starting from square one” and could rise as high as £80m, he believes.

 

Mr Cooper refused to identify his clients, but the New Journal has learned that the owners are a couple with five young children. 

 

They are not from the UK but both were educated in Britain. They plan to use the Hampstead Lane mansion as their main home.