The building of luxury basements under London properties continues:

A lack of room and strict planning laws dictate that the facade of many of London’s picturesque Victorian, Edwardian and Georgian-era neighborhoods must maintain their original character and outward appearance…

“The price per square foot (of basement extension) in areas we work in is probably £400 to £500 per square foot (between $660 and $830 per sq ft). The extra space this brings is probably worth double that,” he added…

“I think for any property with a value over £2 million ($3.2 million) a basement extension is certainly a consideration for the owners,” explained Rob Atkins of London estate agency, Domus Nova. “If you’ve lived in a house for 15 and 20 years and you cannot get a move for the right value then it is an option that can suit that growing family…

“Therefore I wouldn’t be surprised if you see that kind of basement living incorporated in houses for example in Paris, Rome, Vienna or Moscow in the future,” he added.

Without much regulation, it sounds like the incentives are generally there for wealthy owners to create these basements rather than move.

Many of these basements are being built in neighborhoods that are not the oldest in London. At the same time, I would be interested to hear about how such work could interfere with other underground services, whether that is sewers or the Underground or other properties.

Is there any place where this might work in the United States? It would likely have to be in a super-dense area where housing is in high demand. Perhaps Manhattan or San Francisco?