Homeowners will be able to complete small additions such as carports and verandas without the need for building consents if planned law changes are passed in Parliament.
The Government has outlined its plans to amend the 2004 Building Act to help cut bureaucracy.
The changes also aim to make builders more accountable for their work and bring in mandatory written contracts.
The contracts will apply to work above $20,000 and set out expectations, warranties and remedies.
Building and Construction Minister Maurice Williamson says there is a lack of confidence in the sector.
Mr Williamson says builders who are not licensed from March 2012 will be acting illegally and liable to be fined.
Mr Williamson says the Government over the longer term is looking at how to make consents more consistent.
The Registered Master Builders Federation says the success of the changes will lie in their detail and believes amendments are long overdue.
Chief executive Warwick Quinn believes an immediate impact on housing affordability and compliance costs would be unlikely.