Source: Quotable Value
Thursday, 1 October 2026
Construction costs have edged higher once again, despite a small reduction in the price of GIB and some other commonly used building materials.
QV CostBuilder’s latest update shows trade rates increased by an average of 0.2% in September, with a wide range of individual product movements pulling costs in different directions.
Most notably, the cost of plasterboard linings fell by 0.4%, driven by a 1.9% average reduction in GIB products. Plumbing and waterproofing costs went in the opposite direction, increasing by 0.8% and 1.6% respectively.
QV CostBuilder quantity surveyor Martin Bisset said the latest figures painted a mixed picture.
“GIB is one of those products that almost everyone knows because it’s used so widely in construction, so a price reduction there is welcome news,” he said.
“But this month is also a good reminder that construction costs almost never move neatly in one direction. While some products have come back, plenty of others are still getting more expensive.”
QV CostBuilder’s September update applied almost 11,000 current material prices to its construction cost database, resulting in 9,500 changes across Auckland, Hamilton, Palmerston North, Wellington, Christchurch and Dunedin.
Timber was a notable source of upward pressure in September. Structural timber increased by an average of 4.4% across the six centres, timber joists went up 5.2%, and interior and exterior grade plywood cladding increased by 5.6%.
Diesel prices also increased by 2.3% in September, although this was relatively modest compared with some of the movements seen earlier this year.
“Rather than one dominant cost driver this month, as we’ve often seen with diesel this year, we’re seeing a lot of individual products moving at once, both up and down,” Mr Bisset said.
“Some of the bigger increases are in timber and related products, which are used right across residential construction. So even when something as familiar as GIB gets cheaper, that doesn’t necessarily mean the overall cost of building is coming down.”
Mr Bisset said the broader picture remained one of relatively modest construction cost growth, even as activity in the sector showed signs of improvement.
Recent Stats NZ figures show construction activity increased by 2.7% in the June quarter, its largest quarterly rise since June 2023, with residential building contributing to the increase.
“We’re starting to see some improvement in construction activity, but that hasn’t translated into broad-based cost escalation,” Mr Bisset said.
“Cost pressures haven’t disappeared, but neither are they accelerating across the board. This month there are some genuine reductions mixed in with a fairly long list of increases.
“For anyone budgeting a project, that means it still pays to allow for movement rather than assume costs will stay exactly where they are.”
Other notable increases included some formwork rates (12.5%), fire retardant roof underlay and wall wrap (12%), gas water heaters (3%), and reinforcing mesh (2.6%).
QV CostBuilder is New Zealand’s most comprehensive construction cost database. It encompasses everything from building costs per square metre for warehouses, schools and offices, to the supply and install cost of more than 10,000 items, labour rates, labour constants, and more.
QV CostBuilder: costbuilder.qv.co.nz