Record high net migration and low interest rates are putting pressure on the nation's housing market, driving up prices and spurring construction activity.
Data released by Statistics NZ showed residential building consents passed 30,000 for the first time in 11 years in the 12 months through October.
Damage to roads and other infrastructure following the Kaikoura earthquake last month had added to supply constraints through Canterbury and some areas further north, he said.
But Mr Hansen said Northland would not be satisfying demand for logs in the South Island as places such as Christchurch already had big sawmills and enough wood.
However, he said Auckland and overseas markets would continue to have a lion's share of Northland wood.
"Building infrastructure has certainly created demand for saw logs for structural framing. Northland is feeding Auckland so that market is creating demand for sawn logs and, of course, there's the export market," he said.
Mr Hansen said wood processors in Whangarei, particularly those close to Northport at Marsden Pt, were paying $123 a tonne but that price would rise to $126 from January 1.