The Ministry of Business, Innovation and Employment has admitted there are problems with the Building Act.
The Canterbury Earthquakes Royal Commission has begun its final hearing, which is addressing legal and best practice issues relating to the performance of buildings during earthquakes.
Structural engineer John Scarry told the hearing on Tuesday the engineering profession is in crisis and the Building Act needs an overhaul to help stamp out illegal techniques and incompetence in the industry.
The ministry's Canterbury rebuild and recovery director told the commission there are no deep-seated issues, but some problem areas need improvement.
David Kelly said the act lacks clarity about the roles and responsibilities of those in the building industry, particularly regarding accountability.
"It would be fair to say that the roles and responsibilities are not well understood across the sector. This is an issue that's being addressed with further clarification of the roles by way of the Building Amendment Bill. In particular, trying to clarify the accountabilities of the various players in the system."
Amendments to help clarify the Building Act are being considered by a select committee at Parliament.
John Scarry told the inquiry on Tuesday he has been trying to get people to listen to his concerns for the past decade, but has been ignored by most engineers.
The Auckland engineer said buildings throughout New Zealand, including some in Christchurch, are being constructed with illegal engineering techniques, such as the over-bending of reinforcing bars. and many materials being used are inadequate.
Mr Scarry said the Department of Building and Housing is incompetent and needs to be replaced with an independent commission with greater engineering experience, and the Building Act needed to be rewritten.