Builders are doing a roaring trade in Auckland, but it still isn't enough for a booming population.

Westpac's quarterly building activity survey shows construction activity in the city rose nine percent in the last three months of 2014.

But senior economist Michael Gordon says it's still not enough to keep pace with demand.

"We're still seeing effectively more crowding in Auckland. The number of people per house is still going up."

Michael Gordon says seeing more consents issued under the city's housing accord is good, but the market could still be freed up some more.

Michael Gordon says the standouts in the quarter were Auckland and Canterbury, with construction activity up 9% in both regions.