Ray Grehan's Glenkerrin Homes has won a planning battle to build a major residential development at St Loman's Hospital in Palmerston, Dublin 20.

By giving the thumbs up, An Bord Pleanála overruled the recommendation of its inspector to refuse planning permission for the 577-unit development.

The board's decision overturns South Dublin County Council's refusal of planning permission for the development because of the high number of apartments which it said would contravene the county development plan 2004-2010.

An Bord Pleanála said it did not accept its inspector's recommendation to refuse planning permission because of the development's proximity to Liffey Valley and public transport corridors, and said it considered that the mix of residential units,commercial and community facilities proposed would constitute a sustainable form of development.

The St Loman's development will comprise 501 apartments and duplexes and over 70 three and four-bedroom houses in eight blocks. It will also incorporate a leisure centre, crèche, shops and a medical centre.

An Bord Pleanála's decision will surprise many after South Dublin County Council said the development would contravene the development plan. It said the high proportion of apartments - compared to semi-detached and detached homes in the area (which is not zoned a town or district centre) - would not comply with its requirements for a wide range of house types and sizes to cater for the different needs of the population.

In 2004, Maynooth-based Glenkerrin paid the Eastern Health Board €31 million for the 22-acre site which is located beside the N4 and opposite the Hermitage Golf Club.

Glenkerrin is behind other big developments at the Grange in Galloping Green, Stillorgan and in Ballintyre, Dundrum.