Oliver Wainwright: A new billionaires' craze for building elaborate subterranean extensions is making swiss cheese of London's poshest streets but at what cost?
Walking around the stuccoed streets of Kensington and Chelsea today, you are in for a surreal sight. The marching rows of doric columns, pedimented porticoes and dentilled cornices that define these imposing ranks of wedding-cake mansions have been joined by anunlikely addition to the classical architectural vocabulary.
Poking up at regular intervals, thrusting outwards from their moulded openings as if performing a salute to passers-by, are lines of angled conveyor belts. Slowly rumbling away, they reach high above the trees, pouring a continuous stream of rubble into the cradles of awaiting skips. You would be forgiven for thinking that the residents of the royal borough have established a kind ofcoal-mining cottage industry. Or maybe they’re digging for gold?
“It is an absolute disgrace,” says oneelderly resident, out walking her freshly coiffed miniature poodle in between the rows of hoarded-off skips. “It feels like they’ve turned Kensington into a war zone.”
The reason for all this quarrying is notthe discovery of a coal-rich seam beneath the Wrenaissance streets, but the local enthusiasm for subterranean development. Over the past four years, this local authority alone has granted planning applications for more than 800 basement extensions, refused 90, and has a further 20 outstanding. It is the most densely populated borough in thecountry, with no room to build outwards, and no permission to build upwards so the only way is down.
But this desire for digging isn’t to everyone’s liking. Last week a furore erupted when plans were released forafour-storey basement beneath a19th-century schoolhouse in Knightsbridge, for Canadian former TVmogul David Graham.
Tripling the size of the property, this gargantuan pleasure cave would house a ballroom and swimming pool, with hot tub, sauna and massage room, as well as 15 bedrooms, seven bathrooms and 20 toilets, plunging deeper into the earth than the height of neighbouring homes.
“These plans are absolutely monstrous and unnecessary,” said one neighbour, the Duchess of St Albans. “It’s just absolute greed. No one needs that much space. Quite apart from that, the commotion is going to be dreadful.”
“This is totally out of keeping with the relatively small size of other houses in the area,” agreed a spokesman for thenearby Milner Street Area Residents Association. “Why should we all sufferjust so one man can indulge hisfantasy?”
Such fantasies are not restricted to this one man alone. The past five years have seen sprawling underground leisure lairs excavated across west London, from Knightsbridge to Belgravia, Fulham to Notting Hill. They contain playrooms and cinemas, bowling alleys and spas, wine cellars and gun rooms and even a two-storey climbing wall. It is leading to a kind of iceberg architecture, a humble mansion on the surface just the visible peak of a gargantuan underworld, with subterranean possibilities only limited by the client’s imagination.
“Houses in this part of London are trophy asset purchases,” says Peter Preedy, associate director of residential property at Jones Lang LaSalle. “People don’t want to move out, so they have to find a way of bringing everything they want into their homes. These mega basements are not about increasing thevalue of property they are very personal things, which might in fact prove difficult to sell on.”
One of the most personal plans which itself set the precedent for this recent burrowing frenzy dates back to2008, when Foxtons founder Jon Hunt received permission for the most audacious basement of all, a colossal cellar to trump even the swankiest Beverley Hills crib.
Having bought a palatial villa on Kensington Palace Gardens, the most expensive street in the country, he was not to be outdone by his neighbours. Lakshmi Mittal’s nearby “Taj Mittal” already featured an underground complex of Turkish baths and a pool lined with marble from the same quarry as the Taj Mahal. A few doors down, property mogul Leonard Blavatnik hadbought up three former Russian Embassy buildings and since added anunderground swimming pool, gym, private cinema and extensive garaging.
In a surreal competition of keeping upwith the Joneses, billionaire-style, Hunt went one step further into the realms of fantasy. He proposed to dig a 22m-deep hole beneath his garden to house a tennis court, pool and gym, aswell as aprivate museum for his collection of vintage Ferraris. The cavernous chamber would be illuminated from above, through the glass floor of a glistening rooftop infinity pool.
“We were really taking the piss,” laughs Ademir Volic, of Volume 3 Architects, who dreamed up the proposal for Hunt, referring to the fact that such a large-scale extension was at that time, before the Royal Borough of Kensington and Chelsea issued supplemental planning guidance on subterranean developments, a simple matter of making a 150 householder application fee [see footnote].
“We analysed the planning laws andrealised that they cover everything about the surface of the ground, but nothing beneath it. There was nothing whatsoever that could stop us from drilling all the way down to the southpole.”
“Of course, the council hated it,” he recalls. “But we had a barrister, and the policy would not cover their reasons for refusal, so they had to grant permission and it has triggered a whole avalanche of stuff ever since.”
Hunt’s project has since been mired in legal battles with the neighbours notexactly surprising, with the Indian High Commissioner on one side and the French Ambassador on the other and has yet to break ground. Prince William and Kate Middleton, soon to be neighbours over the gilded fence in Kensington Palace, will be breathing a sigh of relief: the project was of such a scale that it would have required a specialist in horizontal digging. And what kind of builder was lined up for thejob? None other than the same contractor that built the channel tunnel.
While Hunt’s cavernous car museum might be at the extreme end of the scale, and never likely to see the light of day, Volic argues that digging down is often the only answer to improving existing properties, given the restrictive planning system above ground in the UK.
“We live on a little tiny island, where we all like the idea of having our own houses with a front and back garden,” he says. “But our Georgian and Victorian stock is so inflexible, frozen in time. We’re selling this city as a forward-looking metropolis, yet we can’t changea single window in a conservation area. Everything has tobehidden underground.”
He also argues that these basement developments serve a useful structural function: “We are dealing with 200-year-old buildings, with all sorts of structural damage in them already. By adding a basement, we are underpinning the whole building, giving these things a proper foundation for the first time.”
But the planning authorities are not quite so enthusiastic. “There may be some truth in saying that inserting a large concrete box beneath a house might stabilize it,” says Derek Taylor, head of development control at the Royal Borough of Kensington and Chelsea (RBKC), and the man being faced with the barrage of ever-bolder basement dreams. “But there is a counter argument, that if the neighboring buildings aren’t also stabilised, then they might well part company from it.”
This is precisely what happened, toresidents’ dismay, in Kensington’s Palace Gardens Terrace this summer, when Goldman Sachs boss Christoph Stanger started digging beneath his 7mproperty to create a playroom forhis children.
After initial excavations, the house began to subside, pulling its neighbours down with it. Cracks appeared within the adjacent basements, and the facades sunk to such an extent that door frames shifted and people were trapped inside.
“We had to call the contractors out six times in three weeks to open our own front door,” said a retired neighbour. “One lady who lives in my block was stuck in her flat because she couldn’t getthe door open from the inside. I had to come and barge it loose.”