A shopping centre under Cavendish Square?

A public park just behind Oxford Street’s John Lewis store could be turned into an underground shopping centre.

Cavendish Square was laid out 300 years ago as a garden, but in the early 1970s, a 3-storey underground car park was built underneath and that’s still there today as a car park.

The car park could only exist as the London Squares Preservation Act 1931 which stops the public gardens being redeveloped didn’t prohibit subterranean developments. The only difficulty they had was that the entrance ramps had to be outside the park, and fortunately, the road was wide enough to accommodate that.

The public park and the car park used to be privately owned and leased to Westminster City Council until January 2062. The car park is sublet by the council on a lease that expires in 2035 and was earning the council around £3 million a year in fees.

Westminster Council took up an option to buy the park a couple of years ago, paying £17 million for the site and last March agreed to start negotiations to terminate the car park lease early so that the site could be redeveloped.

In the meantime, Reef Group has engaged Savills to advise on a project to redevelop the square. Savills says that initial interest has ranged from technology-focused retailers, global office occupiers, leisure brands and medical providers attracted by the Harley Street proximity.

Stewart Deering, Founder at Reef Group, said that “the development will be a blueprint for repurposing space in capacity-constrained urban environments demonstrating what smart-design can achieve.”

(c) Savills

One of the tantalizing possibilities is the reuse of two large shafts leading down to the Victoria line tunnels.

When the Victorian line was being dug in the mid-1960s, apart from the huge rebuilding of Oxford Circus station itself, they also took over part of Cavendish Square as a worksite.

From here, two deep shafts down were dug, and then sideways to reach the Victoria line. One was 80 feet underground and reached the side of the northbound tunnel, while a deeper tunnel ran to the southbound Victoria line and also via a spur to the new Central line interchange passages.

Those tunnels were later backfilled, but usually, when that happens, the tunnel lining rings are left in place to add stability to the infilled material. The tops of those shafts now sit underneath the road ramp used to get into the car park next to the current RBS bank.

The “back of the envelope” idea would be to bring one or both tunnels back into use. They cant be used for passengers, as the deep tunnels don’t go to the correct places, but they could be exceptionally useful for ventilation.

The surplus heat could then being reused to warm the newly built shops or offices that will be filling up the old car park.