"We can't really see any evidence of a housing boom, " said Yolande Barnes, head of residential research at real-estate agent Savills.

WSJ: London Developers Hope for Olympic-Size Boom

Yolande Barnes, director of residential research at the Savills agency, is far more cautious, predicting 22% growth over the next five years.

WSJ: A Diplomatic Breakthrough

According to Yolande Barnes, head of residential research for Savills, another high-end estate agency, movements in London property are closely aligned with those in the price of gold.

ECONOMIST: Housing

"Billionaire activity has been concentrated on high-end urban centers rather than leisure properties in the surrounding countryside or regional sunbelts, " said Yolande Barnes, head of world research at Savills.

CNN: Hong Kong ranks highest for 'billionaire' properties

The math has changed in recent months and years, as government efforts to curb property inflation from the influx of foreign buyers have resulted in new fees and taxes, says Yolande Barnes, head of world research at Savills.

WSJ: The Price of Global High-End Living