House-building in Northern Ireland has slowed due to under-investment in sewers, an expert said.
The number of new dwellings started over July-September quarter was 1,922, a 14% decrease on the same quarter last year, the Northern Ireland housing bulletin showed.
Official estimates suggest Northern Ireland needs around 7,200 new homes each year to keep up with population growth and demolition of older housing.
Justin Cartwright, Northern Ireland director of the Chartered Institute of Housing, said: “This is concerning news – for some time we’ve seen steady growth in the number of new homes built each year, driven by the recovery of private sector development.
“Today’s figures show a disappointing couple of quarters over the spring and summer, dropping back to a level of activity seen four years ago.”
He said Northern Ireland was on course to miss its house-building target this financial year, which could impact on prices.
“One thing that is beginning to hit house-building is the lack of investment in new wastewater infrastructure.
“No house-building can be carried out in areas where sewage treatment works are at capacity, and without greater investment the issue will only get worse.
“The lack of this infrastructure that enables new housing developments is worrying – we need an executive back to ensure that Northern Ireland Water is adequately funded.”
The new-build statistics were published by the Communities Department.