Covid-19 associated effects, such as shipping delays and lockdowns, have caused shortages for basic building materials leading to lengthy delays that are doubling build times and causing cost blowouts.
That was being made worse by large companies, such as Fletchers and Carter Holt Harvey, holding on to their stock, Residential Renovations owner Alistair Carson said.
There was not enough competition in the market so those two companies had all of the country’s product tied up, he said.
That was affecting smaller builders trying to source supplies for their projects, who already had an eight-week wait.
Builders were at risk of having to tell clients they could not finish their job, he said.
"That will mean the building boom we are going through at the moment will come to a halt."
The Government needed to act quickly to resolve the supply of products to prevent that from happening, Mr Carson said.
BuildSmart co-owner Glen Williamson said the building industry was in a "difficult situation" as materials were in such short supply.
The company had bought some products up to six months in advance of a project starting to ensure it could do the job.
It was "very challenging" in the sector at the moment and Mr Williamson believed the Government should have acted months ago to stop it getting to this point.
RenoMasters managing director Andrew Elliot was recently told by a supplier that their factory was working seven days a week to clear the 16 week backlog.
Stock shortages and the ongoing effect of Omicron were making it "incredibly difficult".
Mr Elliot was having to preorder stock between 16 and 19 weeks ahead of a project’s start date.
While it was challenging at the moment, RenoMasters was still receiving up to three calls a day from people inquiring about renovations, he said.
Master Builders Association chief executive David Kelly said it was a "tricky time" for builders trying to access materials.
The organisations did not condone dishonest or anticompetitive behaviour, which would not help the sector in the future, Mr Kelly said
When contacted, Building and Construction Minister Poto Williams said the Commerce Commission was looking at competition in the market.
The commission was considering factors that might be affecting the supply or acquisition of key supplies.
There was also no doubt that Covid-19 and increased global demand had affected international supply chains, which were driving up costs.
"While there is no quick fix to these issues, there are a number of other government initiatives under way," she said.
Fletchers and Carter Holt Harvey were approached for comment yesterday.
