Tech entrepreneur’s £29.95m London mansion with ‘Batman lair’ up for sale

A high-tech London mansion inspired by the Batman film series is being put up for sale. Gadget-obsessed tech tycoon Sergey Frolovichev oversaw a significant extension and redevelopment of the neo-Georgian property in Greenaway Gardens, which has a sale price of £29.95m ($40m), including its own ‘Batcave’ – accessed via a secret entrance. The 1,347-sq-m construction project has taken several years and has retained the facade of the property, originally built in 1934 by the architect Charles Henry Bourne Quennell, while inside was entirely gutted, with the focus on its subterranean opportunities. The 2021 purchase price of £13.35 million has been matched by the rebuild costs. Sergey Frolovichev has decided to sell the mansion on Greenaway Gardens, Hampstead. Info While above ground is still at the shell and core stage, the giant basement is a design workshop with a nod to Mr Frolovichev’s favourite film, The Dark Knight . It is accessed via a hidden staircase from a corner of the games room, concealed by retracting floorboards, and a dark Batman-style for its display cabinets, lighting, tools and 3D printers. He has said he needed the ‘mancave’ as an escape where he could use his hands rather than his brain, as he has a love of woodworking. The home also has a suggested seven-bedroom suite, a triple-height galleried entrance hall, six reception rooms, study, a media room and a health spa with gym, steam room, sauna and swimming pool that can be drained to become a dancefloor. It also has a car-stacker garage, 735 sq m of external terracing and large gardens as well as ground source heating bore holes. Mr Frolovichev's mancave includes a well-equipped workshop. Info But after investing his time and money into the dream project, Mr Frolovichev, who was heavily involved in the success of the Bumble and Badoo dating apps, which were sold to asset manager Blackstone in 2019 for $3 billion, has decided he will not be moving in. He moved to the UK in 2005 but relocated with his family to Lake Como in Italy during the construction and has decided to remain there. Mr Frolovichev designed the project in collaboration with architectural practice SHH, who can be retained or replaced by the purchaser to complete the works to their own specification. Internal fit-out is expected to take another year or so for around £5 million. The gymnasium. Photo: Draper London/SHH Info Craig Draper, founder and managing director of estate agents Draper London, which is marketing the property, described it as a “unique trophy mansion” on one of Hampstead’s most sought-after addresses that provides the new buyer with the “pleasurable finishing elements of such a project where the heavy lifting has been completed”. He said potential buyers would likely be an international family relocating for schools or a billionaire businessperson. Mr Draper said: “The flawless design of the mansion offers contemporary, open-plan style living on all floors, providing an outstanding trophy residence that will appeal to an ultra-high-net-worth individual who wants privacy and the opportunity to imprint their own vision on this important property. "This sale offers a once-in-a-generation opportunity to create one of the finest new residences in Hampstead.”