The London property gold rush shows little sign of flagging. Prime office values have soared more than 30% from June 2009's lows and yields average 5.25%, close to pre-crisis levels.

Now Land Securities, the UK's largest real estate investment trust, says rents are rising too. But while London is booming, there is little to cheer elsewhere in the UK commercial real estate market. Investors need to approach the sector with care.