"Canterbury's housing market is in a period of transition," he said.
After rising strongly following the 2010 and 2011 earthquakes, home-building levels had been pulling back, and there was evidence of downward pressure on rents and house prices.
"We expect to see a further moderation in construction activity over the coming years," Ranchhod said.
While that signalled some drag ahead on the Canterbury economy, firmer activity in other parts of the economy was providing some offset and at present business confidence in the region was "very positive", he said.
Ranchhod said "the missing piece of the puzzle" was low interest rates which had made the capital gains on housing assets, and relatively high returns from home building, very attractive to many investors and developers.
"Affordability is a particular challenge for many first-home buyers, and those looking to upgrade, who find themselves competing to purchase homes against developers who have a different set of financial constraints and incentives," he said.
The capital gains and high returns also helped to explain why strong house price increases had not been limited to Auckland, with prices also rising rapidly in areas that did not have the same degree of housing market tightness.
He noted that rising mortgage rates in recent months, combined with a tightening in lending restrictions and pressure on housing affordability, had "sapped some of the momentum" from the housing market.
Concerns about housing supply and low affordability could prompt a reduction in the number of people moving into Auckland, or encourage a shift to other regions, Ranchhod said.
"We continue to hear reports about high living costs in Auckland making it harder to attract and retain staff in the region, especially with wage growth failing to keep pace with house prices."