Skills shortages, onsite safety and the election will be topics of discussion at the Certified Builders Association of New Zealand's biggest-ever annual conference.
The event kicks off today at the Claudelands Event Centre in Hamilton.
Chief executive Grant Florence said more than 600 builders have registered , over 500 of them from out of town.
The conference begins with an expo featuring 70 trade stalls and will conclude with the association's annual meeting on Saturday afternoon.
Florence said this year's event, the first at Claudelands, will be the 16-year-old association's biggest annual conference, with attendance about 30 per cent higher than the previous best - "a reflection of more confidence in the building industry".
He said the industry held steady during the global financial crisis, during which some builders exited the industry and some moved to Australia.
But Florence said the association's membership was growing again, and included about one-third of all New Zealand builders.
Twenty to 30 builders registered every month, and total membership was just under 3000.
He said Certified Builders had the most stringent membership requirements of any building trade association in New Zealand because all members must be trade-qualified.
The association's membership was driven by growth in the building industry, and Florence said the number of building consents was up.
"[They are] probably the highest now that they've been in four or five years."
He said the cycle of boom and bust meant that in boom times the industry could be short of skilled workers.
Florence said some new builders were coming into the industry, particularly in Auckland and Christchurch.
Certified Builders is involved in initiatives designed to attract new apprentices to building, including the Building and Construction Industry Training Organisation's "reboot" grants and the Industry Training Association Building programme, which Certified Builders runs with polytechnics around the country.
"The number of apprentices we've got under that programme is at a high as well," Florence said.
In addition to industry suppliers and building materials manufacturers, the expo will have stalls dedicated to builders' health.
Free hearing checks will be provided.
The conference will include opening and closing speeches by the Minister for Building and Construction and Minister of Housing, Nick Smith, and Labour spokesperson for building and construction Clayton Cosgrove.
The final of the New Zealand Carpentry Apprentice Challenge will also be held.
Apprentices will construct benches, which will be donated to Waikato organisations after judging, and compete in an obstacle course challenge.
The expo will be open to all tradespeople this afternoon from 1pm.