The planning regulator has warned South Dublin County Council it “risks frustrating the implementation of national housing policy” and undermining the delivery of housing targets, by failing to rezone enough lands for new homes. Councillors in June voted against rezoning lands at St Edmundsbury in the Liffey valley near Lucan; Finnstown Castle, between Lucan and Adamstown; and Coldcut Road, south of the Liffey Valley shopping centre.The council’s chief executive Colm Ward had proposed rezoning the three sites, which combined could accommodate more than 1,700 homes, following an edict last summer from Minister for Housing James Browne that all local authorities must provide significant additional land for housing,The Finnstown Castle lands, most of which are owned by Adamstown developer Maplewood, and Coldcut Road sports club’s lands are currently zoned as “open space”. However, the St Edmundsbury lands, owned by businessmen John Magnier and JP McManus, are zoned as “high amenity” due to their environmental and natural amenity value. More than 1,600 submissions were made to the council opposing the St Edmundsbury rezoning, with Lucan locals suggesting the lands should instead form part of a Liffey valley park.In a letter to the council, the Office of the Planning Regulator said the councillors’ decision to block rezoning did not comply with the Minister’s direction or the National Planning Framework and should be reversed. The decision “risks undermining the delivery of housing targets”, deputy planning regulator and director of planning policy implementation Anne Marie O’Connor told the council.“In particular, the reduction of residential development capacity and the introduction of additional constraints on housing delivery have not been supported by sufficient evidence to demonstrate that housing growth requirements can continue to be achieved,” she said.[ Removal of ‘unconscionable’ housing ban on Magnier and McManus Liffey Valley lands urgedOpens in new window ]The lands at Coldcut Road were “relatively small” but could still facilitate housing growth.“More concerningly”, the Finnstown Castle and St Edmundsbury sites “comprise substantial land parcels in highly sustainable locations that are well integrated with the existing urban fabric of Lucan”, O’Connor said.“These lands represent a significant opportunity to deliver much-needed housing in proximity to established employment centres, services, public transport and community amenities. Their development is therefore critical to meeting housing need in a planned and sustainable manner.“The office remains of the view that these lands are required to support housing delivery,” she said.A report on the regulator’s recommendations and other zoning submissions will be presented to councillors for a fresh vote in the autumn.Developer Michael O’Flynn, who plans to build almost 500 homes on the St Edmundsbury lands in partnership with McManus and Magnier, said it was “unconscionable” that the development of homes on the land was being blocked “at a time of a national housing emergency”.The plans for the land were “about considerably more than housing”, he said.[ From a dump to a national park to housing: how plans for Liffey Valley Park have changed over the yearsOpens in new window ]“Our ambition is that St Edmundsbury would become part of the long-standing vision for a Liffey valley park,” he said. “This provides the opportunity to formalise what is currently unauthorised access to this area. This land is currently private, and its opening is part of an overall plan for the Liffey valley.”Campaign group the Liffey Valley Park Alliance urged the council to retain the high-amenity designation on the lands. “Doing so will preserve an important element of the county’s green infrastructure network and protect its environmental, landscape and community value for future generations,” it said.