Homeowners in England are being given the green light to build larger extensions without planning permission.
Temporary rules, which allowed bigger single-storey rear extensions without a full planning application, are being made permanent.
Additions to terraced and semi-detached homes can be up to 6m, while detached houses will be able to add even larger structures, up to 8m long.
Neighbours will still be consulted and can raise objections to extensions.
Since 2013, 110,000 people have taken advantage of the temporary rules, which doubled the previous limits of extensions that didn't require planning permission from the local authority.
Instead of waiting possibly months for approval, homeowners notify the council of the building work beforehand, and council officials inform the neighbours.
If they raise concerns, the council decides if the extension is likely to harm the character or enjoyment of the area, and may block the plans.
In Scotland, Wales and Northern Ireland, rear extensions more than 3m or 4m long will continue to require a full planning application, which places the design and impact of the building under more scrutiny.
Housing minister Kit Malthouse said the change in England means "families can grow without being forced to move".
He said: "These measures will help families extend their properties without battling through time-consuming red tape."
Impact on neighbours
But Martin Tett, planning spokesman for the Local Government Association, which represents UK local councils, said: "The planning process exists for a reason."
He acknowledged the relaxed rules were popular with homeowners, but said it meant councils had little opportunity to consider the impact of extensions on their local area.
"We do not believe this right should be made permanent until an independent review is carried out of its impact, both on neighbouring residents and businesses, and also the capacity of local planning departments," he said.
The Ministry for Housing, Communities and Local Government said it was also removing other planning rules to allow business owners to respond to changes in England's high streets.
It means shops can be converted into office space without a full planning application being made.
Shops, offices and betting shops will also be able to temporarily change to community uses such as libraries or public halls.