In the words of the prime minister, it's time to get the planning system 'off people's backs', while reviving the economy at the same time.

For many people in Norfolk, the closest they come to the planning system is having to navigate it to get permission to build a conservatory or an extension and it's surely no coincidence that the government has honed in on that very element.

As part of announcements made yesterday, people will be allowed to extend their homes by up to eight metres (just over 26ft) without having to seek full planning permission.

Downing Street said a month-long consultation on allowing larger extensions without planning permission will start next week with an aim of the measures being in effect by the end of the year, to run for a 'time limited period'.

But that has sparked concern in the county, with critics warning such a free-for-all could see ugly and overbearing extensions put up with no thought for the impact on neighbours.

Claire Stephenson, leader of the opposition Green group on Norwich City Council, said the changes would not produce the economic boost the government craves, but would diminish democracy.

She said: 'I think these proposals are extremely worrying. There's a tried and tested planning system at the moment and there are very good reasons for it.

'It's a democratic system and if somebody objects to their neighbour's extension plans, their views will be taken into account.

'These changes mean people could potentially build quite large extensions without having to go through that process and that could have an effect on people who live around them.

'I think the government is being quite short-sighted, as I don't think that's going to deliver the economic boost they say it will.'

Ministers have also decided that developers will no longer have to wait five years to apply to change affordable housing requirements if they are making sites 'commercially unviable'.

The government says such measures will boost the economy and Norfolk supporters of the move say it will be a shot in the arm for the local economy.

Prime minister Mr Cameron said: 'This government means business in delivering plans to help people, build new homes and kick-start the economy. We're determined to cut through the bureaucracy that holds us back.

'That starts with getting the planners off our backs. Getting behind the businesses that have the ambition to expand. And meeting the aspirations of families that want to buy or improve a home.'

The move was welcomed by John Fuller, Conservative leader of South Norfolk Council, although he insisted it did not mean the planning system in the county was broken. He said: 'Let's not lose sight of the fact that people already have permitted development rights for conservatories and extensions already, so this is really just building on what is already there.

'I don't think we should get carried away with the notion that planners have not played their part because we have and we are.

'We know that for every house built that creates 2.1 jobs, not only with the building of the home, but in people getting kitchens fitted, carpets put in and so on.'

On the issue of affordable homes, he said councils already negotiated with developers over ratios and insisted the changes would not make councils a soft touch when it came to dealing with them in the future.

Indeed, the changes are specifically targeted on sites which have got permission, but have yet to be developed because the obligation on the percentage of new homes makes sites 'commercially unviable'.

However, Caroline Davison, from the Norfolk branch of the Campaign to Protect Rural England, said: 'It's not the planning system which is getting in the way, it's the economy, and we're not sure how these ideas are going to make it any better.'

The Local Government Association said it was a 'myth' that planning departments were the reason houses were not being built.

The association yesterday published figures which revealed a bumper building backlog of 400,000 new homes which have received planning permission but have not yet been completed, with building yet to start on more than half of approved plots.

And Paul Clarke, from the Norwich office of property consultants Bidwells, said, while there were major delays in the planning system, the problem went beyond town and city halls.

He said: 'Builders won't build unless there are people with mortgages who can buy the homes and landowners won't sell land without an incentive to do it and I still don't see a huge incentive for landowners to part with their land. 'While all these measures in the round are for the good, something more needs to be done with the planning system. It does need to refresh itself so it is a lot more open and transparent, because you cannot have decisions taking so long to be made.'

The government also announced another 16,500 first-time buyers are to receive help getting on the housing ladder under an extension of the FirstBuy scheme, while new legislation will provide government guarantees of up to �40bn of major infrastructure projects and up to �10bn of new homes, including a move to guarantee the debt of housing associations and private sector developers.

The government also unveiled proposals to put the worst planning departments into 'special measures' if they have failed to improve the speed and quality of their work and allowing developers to bypass councils.

dan.grimmer@archant.co.uk