It has estimated that average rental yields on commerical properties have fallen from 8.5% in 2001 to 6% now, substantially reducing the margin over interest rates. In some cases yields are much lower, with the freehold on a Barclays branch in Stansted recently selling to an investor at a rental yield of just 3.4%

One of Britain's best known property entrepenuers, Nick Leslau, now thinks the market is overheated. He turned bearish just over a year ago, selling the majority of the properties his company owned apart from £1.3 billion worth of pubs, Travelodge hotels and nursing homes.