The Department of Building and Housing is adamant its licensing scheme for builders is sound, despite industry concerns.
About 4000 builders are now part of the three-year-old scheme, which aims to improve standards of building design and construction.
Radio New Zealand has been told by builders and architects that builders who are not good enough are getting licensed.
In particular, there are questions about how thorough reference checking is.
The Certified Builders Association says it has heard such concerns.
But the Department of Building and Housing says the process to obtain a licence is very stringent and stands behind its reference checking.