As of next month, extensions of up to two storeys will be permitted as long as they extend no more than 10ft from the back of an existing property — enough for a small kitchen or spare bedroom.
Loft conversions will also be allowed without planning permission, as long as they extend no more than 20cm (about 8in) from the eaves of a property. They must also be no more than 50 cubic metres in size — roughly the equivalent of a room 18ft by 12ft. In conservation areas, loft conversions will still be restricted but single-storey rear extensions will be permitted.
The rules will remove as many as 80,000 householders a year from the planning system. About a quarter of all home development projects that currently require planning permission will be able to go ahead without formal authorisation from councils.
Ministers said the relaxation of the rules would make it easier for those who were struggling to move house because of the credit crisis to extend their homes instead.
However, there will be new restrictions on home owners who want to pave their front gardens. In order to cut down on the volume of water flowing off driveways into drains, home owners will need planning permission if they want to lay more than five square metres of asphalt or other impermeable materials.
Paving in two strips to act as “wheel tracks” for parking will effectively escape the restrictions, as will driveways using water-permeable surfaces.
Domestic planning applications have more than doubled in the past decade to 330,000 last year. They can cost thousands of pounds and leave home owners mired in red tape for months, even though 90 per cent of applications are eventually approved.
By extending the “Permitted Development” regime, ministers aim to prevent unnecessary applications for relatively minor alterations.
As long as building projects fall within the new limits, neighbours will not be able to object. Government officials say the new restrictions have been set to ensure that no “obtrusive” developments will escape the planning system.
Local councils will have discretion to vary the rules, meaning that people in heavily-developed areas may not get as much freedom to develop even under the new rules.
Building regulations will remain in place, meaning that householders will still have to demonstrate that alterations are constructed to health and safety standards.
The Royal Institution of Chartered Surveyors also supported the scheme but warned that it could increase tensions between neighbours.