Dublin City Council has voted to allow housing development on religious and institutional lands, a move that follows a legal challenge by the Sisters of Charity.

The High Court ruled last year that a ban on private residential development on all institutional lands in the city's current development plan was too restrictive and quashed the zonings known as Z15.

A special meeting of councillors tonight agreed to a city manager's report that redefined Z15 zoning to state that residential is "open to consideration".

It applies to more than 1,800 acres in the city area owned by institutions, including religious orders, schools, hospitals and army barracks.

"Open to consideration" means that planning applications for housing can be made on a case-by-case basis, although any development would be required to leave 25% of the total site as open space.

In the case of the site for the National Childrens' Hospital at St James’s Hospital, the councillors said that it should have special consideration that could be done by variation of the development plan.

Councillors also agreed to a Z12 zoning, which makes housing a "permissable use", on five sites totalling 56 acres, including the Sisters of Charity grounds on Long Mile Road and RTÉ's campus in Donnybrook.

Permissable use means that planning applications for housing that are within guidelines could expect to be granted.

The councillors voted against the manager's recommendations by giving Z12 rather than Z15 zoning on parts of three sites in Sandymount, which are lands owned by the Sister of Charity, Enable Ireland and Rehab.

A further 18 acres on 13 sites are now zoned Z1, which allows general housing, including part of the grounds of St Paul's College, Raheny and Dominican Convent, Navan Road.

The manager's report stated that these Z1 rezonings are on land parcels that contain previous residential development or are separate to the main uses of the site.

The report stated in general that the city already has enough serviced land for future population growth and that institutional lands are better suited to provide social infrastructure and schools in particular.

The zonings passed this evening have already gone through a period of public consultation.