London’s Mayfair neighborhood surpassed Manhattan as the most expensive market in terms of price per square foot, according to a new report by London-based luxury residential brokerage Beauchamp Estates. The average Mayfair ultra-prime home now costs £3,853/SF while Manhattan lags at £3,575/SF.

Manhattan is still more expensive overall, averaging £21.5M for an ultra-prime home, compared to Mayfair’s £18.4M.

Beauchamp Estates’ report notes that demand for ultra-prime residential property remains solid and the population of ultra-high-net-worth individuals, defined as having a net worth of at least $50M, is expected to increase.

“Our view is that 2017 will not bring any dramatic swings in values, rather it will be a year in which buyers and sellers remain calm and measured,” the report said.

The report acknowledged London is still struggling with Brexit and new Stamp Duty taxes while Manhattan is absorbing the "Trump Effect." The result will be a slowdown in new luxury builds, according to Beauchamp Estates.