Supplies of plasterboard have been boosted, with four alternative plasterboard products to GIB now able to be used as a substitute.

The Ministry of Building, Innovation and Employment started looking at how to free up plasterboard supplies during a nationwide shortage of the popular building product.

Twelve importers of plasterboard - four of them new - have 100 containers on their way to New Zealand.

Elephant Board, USG Boral, ProRoc and SaveBOARD now meet Building Code requirements and have been approved for sale.

Until now, Fletcher Building's GIB had about 95 percent of the market.

Kāinga Ora was to use a different plasterboard product for its retrofit programme over the next 12 months - about 400 houses worth - a move calculated to try to free up the domestic supply.

Next week the Commerce Commission is scheduled to deliver its draft report from an investigation into competition in New Zealand's residential building supplies markets.

Main image: Different types of plasterboard are now legally allowed to be used in New Zealand, in response to a shortage of GIB.