People building or renovating their homes may have to increase their budgets, as one of the country's major timber suppliers halts some local supplies.
Carter Holt Harvey has stopped supplying structural timber to Bunnings, ITM and Mitre 10.
Master Builders president Kerry Archer said the move came as a surprise, and was probably because the export market was more lucrative.
Archer said while Carter Holt Harvey was not the only timber supplier, it could mean construction projects cost more as builders try to source supplies elsewhere.
"You can't blame people if they're getting better prices for their logs overseas. It makes it hard to compete I guess, and it's just going to ramp up prices once again.
"Timber's already gone a couple of times this year. Once again it's supply and demand, so if there's a lack of supply then demand goes up and unfortunately costs will go up with it."
Master Builders plans to discuss possible solutions this week.