A High Court judge today spared a Victorian warehouse in Belfast city centre from demolition for a second time.
Mr Justice Treacy quashed a renewed planning decision to have the historic Athletic Stores building pulled down and replaced with residential and retail premises.
He ruled that the Department of the Environment failed to properly consider a policy presumption in favour of retaining buildings in conservation areas.
Jubilant heritage campaigners who brought the legal action claimed it was a significant verdict which reaffirmed the importance of protecting areas of unique character.
Although the 19th Century linen warehouse on Queen Street is not listed, it is in a conservation area.
In May 2012 the Department gave fresh planning permission for it to be demolished and redeveloped.
Serious structural flaws in the building and the disproportionate cost of repairs were identified.
The estimated bill for retention and renovating was in the region of £4 million.
The decision prompted a further judicial review challenge by the Ulster Architectural Heritage Society (UAHS).
In 2010 the charity had succeeded in getting a previous authorisation for demolition quashed by the High Court.
Planning chiefs were ordered to reconsider the application by developer Carlisle Property Developments Ltd to build apartments, ground floor shops and underground car parking on the site.
Lawyers for the society argued that the latest decision was both irrational and in breach of planning policy.
They claimed the proposed development would inflict harm on the conservation area, and that all other possible alternatives were not fully explored.
Delivering judgment today, Mr Justice Treacy said a planning report which recommended approval of the redevelopment erred in considering there is no presumption in favour of retention of buildings in conservation areas.
He pointed out: "Conservation areas are designed as such because taking the buildings together, they form an area of particular architectural or historical interest.
"There is a presumption in the policy that any building which adds to this interest factor should be retained."
Although determining weight was given to retention and repair not being economically viable, the judge held that the Department is not obliged to change the status quo.
Rather than being the only option, if the planning application was refused the building would continue in its current use for the time being.
Nothing bad will immediately happen other than the effect of time on the fabric of the building which it is estimated will eventually render it unusable in 30 years time, he said.
Mr Justice Treacy confirmed that key documents leading to the ultimate decision overlooked the existence of the presumption in favour of retention.
Granting the application to have the decision quashed, he said: "For this reason I hold that the Department failed to properly take into account a very relevant consideration."
A further hearing was listed to decide remedies and costs.
Outside the court UAHS spokeswoman Rita Harkin claimed the decision to approve demotion had been based largely on short-term economic considerations.
Stressing the need to apply planning policy thoroughly, she said: "Conservation areas are special places with enormous potential to create long-term economic prosperity.
"In order to realise that potential, those charged with looking after them need to defend buildings of character, such as this 19th Century warehouse."