The level of social housing unfitness in Northern Ireland has risen for the first time in 40 years.
An increase in the number of empty homes and a reduction in the amount of public money available for repairs has contributed, said the Housing Executive.
The 2011 house condition survey showed an increase in the level of unfitness from 2.4% in 2009 to 4.6% last year, equal to 35,200 dwellings.
Housing Executive chairman Brian Rowntree said 80% of all unfit properties were vacant, with 53% owner occupied and 19% privately rented.
"This would suggest budgetary pressures on households and landlords and may also reflect the much lower level of resources available to lower income households through home improvement grants," he said.
Grants for replacements and improvements to houses rented to tenants on housing benefit have been slashed in recent times. There are approximately 55,000 vacant properties in Northern Ireland at any one time.
The review also highlighted that the social housing sector will continue to expand, but at a much reduced rate. Meanwhile, the rate of owner occupation is likely to continue to decrease and housing benefit changes may impact on the private rented and social housing sectors.
Mr Rowntree said: "Although we have seen more homes become affordable in terms of price, we are also seeing falling household incomes, rising unemployment and the more cautious lending by banks and building societies pointing to a subdued housing market."
An extra 2,000 social homes are required each year, although financial resources will not allow this level of newbuild.
Mr Rowntree warned: "Ongoing changes to the housing benefit system and their impact on affordability for tenants and viability for landlords may have an adverse effect on the sector, although it is too early yet to reach any definitive conclusions."