Housing is in short supply, but there is a surplus of offices - commercial property vacancy rates stand at 7 per cent to 9 per cent - so the government wants to make it easier for property owners to turn unwanted business space into much-needed flats.

Jonathan Manns, senior planning surveyor at estate agency Knight Frank, said the main beneficiaries of the proposed change would be people who owned or had the ability to purchase commercial property.

'While first-time buyers would gain the opportunity to convert relatively cheap business premises, this would also be available to private developers who might compete with them for property,' said Manns. 'In an era of restricted finance, incurred through tightening of mortgage lending criteria and earnings ratios, the private developer would certainly seem to have the upper hand.

'What will be the most interesting is the effect on property owners, who may see an increase in 'hope value' attached to their property or choose to convert properties themselves to secure an uplift.'

Roger Hepher, head of planning and regeneration at estate agency Savills, welcomed the proposals, but said the 'devil is in the detail'. Some offices would not be suitable for conversion. For example, they may lack outdoor space for children or rubbish storage facilities, or might be located far from shops and public transport, he said.

Richard Donnell, director of research at property analytics business Hometrack, said developers must overcome environmental obstacles when converting offices into homes.

'Applying for change of use [planning permission] has always been available,' Donnell said. 'The problems with conversions are the costs involved set against the demand for energy efficiency standards and sustainable housing. It is probably more viable to demolish a building and rebuild.'

If the proposals become law, they would have limited effect on the overall housing market, Manns said. The government wants 232,000 new homes built each year until 2033. Today, the number of homes that could be created from converting vacant offices was 266,000, Manns said. This was about 4 per cent of the total number of new dwellings needed over the next 22 years.

The changes would have little impact on residential prices, Donnell said. 'We will continue to see a lack of new development and this will keep prices relatively high,' he said.

Hepher warned turning offices into flats in some locations, like the City of London, might undermine commercial property markets.

Supply shortage

Britain's government wants this many new homes built each year until 2033 to meet demand: 232,000