Government figures show that the number of new homes built last year was 78,027, down 16.5% on 2006's record 93,419.
For the final three months of 2007, house completions were 21,622, a drop of 20% from a year earlier.
25% of houses built last year were single houses, while apartments accounted for 24% of the total.
The figures also show that the number of new home guarantee registrations last year fell by 42.5% to 38,351, with a near-83% fall in County Longford.
