A legal challenge by three residents of Dublin’s embassy belt to the constitutionality of fast track planning laws could derail plans for over 16,000 housing units.

The litigants, who include billionaire financier Dermot Desmond’s wife Pat, are opposed to plans for more than 600 apartments on former RTÉ land.

But their case also has implications for dozens of other proposed large scale housing developments around the country currently being considered by An Bord Pleanala.

The High Court action was initiated on Friday by Mrs Desmond, former Irish Sugar managing director Chris Comerford, and businessman John Gleeson, all of whom live on Ailesbury Road in Dublin 4.

In a statement issued to the Irish Independent, they said they were challenging the legality of the fast track strategic housing development process introduced by Housing Minister Eoghan Murphy.

This allowed developers submit planning applications for large developments directly to An Bord Pleanala, which usually deals with planning appeals, instead of first having to lodge them with a local authority.

The law was introduced as a temporary measure in 2017 to speed up the planning process, with the Government estimating it could shorten by a year the timeframe within which a final decision can be made.

However, lawyers for Mrs Desmond, Mr Comerford and Mr Gleeson are set to argue the law is unconstitutional and having a detrimental effect on communities around the country. Their case is against the Housing Minister, Ireland and the Attorney General.

If it is successful, there would be major ramifications for efforts to increase Ireland’s housing stock.

There are currently 47 strategic housing development applications, for a total of 15,700 housing units, awaiting a decision from An Bord Pleanala between now and June.

The list does not yet include the 611 apartments and three townhouses Cairn Homes wants to build on a 3.5 hectare site in Donnybrook bought from RTÉ in 2017 for €107.5m.

An Bord Pleanala gave Cairn Homes the green light last October to submit its plans for the site, but it has yet to do so.

In their statement, the litigants said the fast track law operated “outside the normal democratic planning governance framework that is subject to checks and balances, transparency and accountability”.

They said the right of the public to participate in the planning process in any meaningful way, and the right to appeal, had been removed.

They claimed the law would not just have a detrimental effect on their homes but also on many communities around the country.

The litigants said they were in favour of “fully and properly integrated sustainable development”, but claimed current housing and planning policy was flawed. “Instead of delivering appropriate and sustainable housing for families, first time buyers and downsizers, it favours build to rent schemes and development types that attract investment funds and financial market speculators,” the statement said.

Cairn Homes declined to comment.

Online Editors