House Builders Raise Concerns About Poor Sewage Infrastructure

Build Homes NI, the representative body for Northern Ireland’s largest housebuilders, has raised concerns that the development of over 15,000 homes in the region is being impeded by a lack of capacity in its sewage system.

The worst affected council areas are Mid Ulster (2,337), Belfast (1,933) and Derry City and Strabane (1,775).

The impact on house building was confirmed by the Minister for Infrastructure, Liz Kimmins, in response to a question in the Northern Ireland Assembly this month.

It comes at a time of record levels of homelessness across Northern Ireland. There are now almost 50,000 applicants on the region’s waiting list for social housing, including almost 14,000 in Belfast.

Build Homes NI Director, Paul McErlean, said:

“Wastewater is critical infrastructure, but years of underinvestment has left much of Northern Ireland’s sewage network at full capacity. No capacity means no new connections and that means that new developments, be that housing or factories, could be refused planning permission.
“NI Water has 68 wastewater treatment works with no capacity and a further 107 networks with restricted capacity. As a result, the development of 15,386 homes in Northern Ireland is being impeded and housebuilding in the region has fallen to historically low levels.
“This is terrible news for people trying to get onto the housing ladder for the first time and helps explain why increases in rent and house prices in Northern Ireland are the fastest growing in the UK.”
According to the Department of Finance only 6,624 new private and social housing homes were built in Northern Ireland in 2025.

Mr McErlean added:

“The underlying problem is chronic underfunding of Northern Ireland Water which receives the vast majority of its income from the Northern Ireland Executive.
“As a result, our members have confirmed that the pipeline of housing development sites is beginning to dry up and that they are being forced to look outside of Northern Ireland for work.
“At present the Northern Ireland Executive is following a ‘three-pronged’ approach to wastewater issues but this is wholly inadequate given the scale of the crisis and the £2billion deficit NI Water faces in its next funding period.
“We need the Northern Ireland Executive to provide a long-term solution to our growing wastewater crisis. Until that happens the public will pay the price of political inaction through higher housing and rental costs, lost jobs, lost economic growth and pollution caused by untreated sewage spills.”
A report produced last year by the NI Chamber of Commerce, the NI Federation of Housing Associations and the Construction Employers Federation suggested that the poor state of Northern Ireland’s sewage network was costing the economy £2.5billion (Gross Value Add).
The NI Independent Fiscal Council also concluded in a separate report that in the absence of additional funding from Westminster, the Executive would have to raise additional revenue from domestic charging or other sources if NI Water was “to deliver high quality and environmentally sustainable services and to be able to support residential and commercial development needs.”