The Bloomberg U.K. Home Builders Index has gained 36 percent this year as rising sales to foreigners boosts shares.

Berkeley Group Holdings Plc, the U.K.’s third-largest homebuilder by market value, sells 40 percent of its properties to people living outside the U.K., Managing Director Rob Perrins said in a February interview. Shares of the homebuilder, which has offices in Singapore, Dubai and Hong Kong, have increased by almost a 20 percent this year.

Only one in seven foreign buyers of new London homes will live in the property and the remainder plan to rent them out, Chicago-based Jones Lang said, citing a survey of buyers.

“Without international investors, most residential developments in London wouldn’t happen and the housing crisis would be even greater,” Challis said.

London’s population is set to increase by about 15 percent to 9.4 million by 2021, the city’s governing councils said in a February report. That will lead to a shortfall of about 250,000 homes by 2020, according to the report.