Longer opening hours at the Dome due to come into effect this April will increase potential daily visitor numbers from 25,000 to 45,000.
Office refurbishment costs an average of £448 per square metre compared with £797 to build a new one, according to a Building Maintenance Information report. The difference on flats is much less marked, at £426 for a refurbishment compared to £529 for new build.
The Queen is clinging on to her lead over the Spice Girls in the super rich stakes with £390 million compared to the pop band's combined £112 million, according to the Financial Times.
In 1999, 35,000 houses in Britain were self-built.
Housebuilding figures are up 3 per cent on last year over the last quarter with 38,000 new houses underway. 13,800 new houses were started in January.