The Building Act is going to be changed so that builders are more accountable for their work, the Government said today.

Building and Construction Minister Maurice Williamson said there would be a greater incentive to "build it right first time" while red tape and bureaucracy would be cut.

Legislation to be introduced to Parliament this year will:

* Explicitly state that builders and designers are accountable for meeting Building Code requirements;

* Introduce mandatory written contracts for building work above $20,000 that sets out expectations, warranties and remedies, and how any disputes will be resolved; and

* Require those doing the work to explain what, if any, financial back-up or insurance they have to remedy any faults.

"I expect these measures will lead to fewer disputes and see most arguments sorted out quickly and relatively cheaply," Mr Williamson said.

"We want to make it easier for homeowners commissioning building work to hold contractors to account for fixing any defects that arise."

The changes will also see some minor work, such as building a carport or veranda, exempted from the need for a building consent.