The Canberra Liberals have vowed to repeal the ACT Government's solar access laws if they win government at next year's election.

The laws, introduced in 2013, are designed to ensure new houses are positioned to maximise the benefits of natural sunlight and reduce heating costs.

They also prevent a development or extension from casting too much shade on a neighbouring home.

The Canberra Liberals tried to block the changes to the planning regulations, but they were passed with the support of the Greens.

Today, Opposition spokesman Alistair Coe said the Canberra Liberals would cut the solar access laws if elected.

Mr Coe said the legislation had resulted in a number of houses being built facing the wrong direction.

"The ACT Government has actually created worse solar access when it comes to block design," he said.

"These blocks are now inefficient and we want to reverse this to once again get back to good design principles."

Mr Coe said when the legislation was introduced it was condemned by builders and industry, including the Housing Industry Association and the Property Council.

"The design rules which the Government has put in place have resulted in some houses costing $10,000 to $50,000 more than they should," he said.

"People are excavating houses and poorly designing them in order to comply with these rules.

"These rules will have intergenerational effects, because these houses will be standing for 50, or perhaps even 100 years.

"It's very important that we overturn these rules as soon as possible."