Up to 10 multi-storey buildings will have to be checked to see if their seismic reinforcing steel is good enough, or if they need fixing.
The Ministry of Business, Innovation and Employment (MBIE) says its efforts to identify buildings that contain the mesh is proving difficult.
The buildings tracked down so far have all been traced through a single mesh supplier. Several suppliers are operating in New Zealand.
The Ministry was forced to begin the search when the testing of steel mesh was exposed as flawed, four years after it began to be sold in this country in a response to the Christchurch earthquakes, as standards were boosted to make concrete slabs more resilient.
MBIE said now that it had found some commercial buildings with the mesh, engineers and councils would work to assess if the buildings had enough ductility, or if they needed altering.
It is also going to ask engineers who have used the mesh recently to check that those designs meet the Building Code.