In a ruling that underlined the need to preserve the viability and vitality of town centres, Scotland's Court of Session found that North Lanarkshire Council had failed to properly assess whether the expansion of the Westway Retail Park would protect and enhance downtown Cumbernauld.
The decision represented an important victory for Bridges Antonine LLP, which owns the Antonine Shopping Centre in the town centre, which is already struggling with retail contraction and vacancy issues.
The Westway Retail Park covers 18.7 hectares and is about 2.9km from Cumbernauld town centre, said Lord Burns, who gave the court's decision.
It has extant planning permissions, going back to 2004, which permit a total of 30,675 square metres of retail floorspace, the court heard.
However, only 12,610 square metres has so far been built and 3,317 square metres of that remains unlet.
The case concerned an application to, amongst other things, construct up to 6,457 square metres of retail space in addition to that already built.
The majority of that - 4,599 square metres - would be comparison floorspace, used to sell bigger ticket items, such as cars and major appliances. The remaining 1,858 square metres would be convenience retail floorspace. The consent included a condition to ensure that the quantum of such uses would not be exceeded at the site.
In granting planning permission in June last year, North Lanarkshire's planning committee found that the proposals would draw only about four per cent of convenience expenditure away from Cumbernauld town centre.
The committee considered that acceptable and that it would not cause significant harm.
The committee noted that the effect of the permission would also be to restrict the retail park's overall retail floorspace to 18,968 square metres, much less than the 30,675 square metres permitted under the extant permissions.
It found that the proposals did not conflict with the regional strategic development plan or the local plan, which supported comparison retail or leisure uses of the site.
An independent sequential test had been carried out which identified no alternative development site in, or closer to, the town centre.
And the council emphasised the desirability of diversifying existing commercial centres and enhancing their environs to make them more competitive.
However, in overturning the permission, Lord Burns upheld Bridges Antonine's arguments that the council's reasoning was "perverse and inadequate".
The judge noted that the 2017 strategic development plan for the Glasgow city region underlines the importance of "protecting and enhancing" existing town centres.
He accepted that those words should not be read literally in that few, if any, out-of-town proposals would be capable of achieving such a high standard.
But the proposal was a strategic one and the council was nevertheless required to fully assess whether the expansion of the retail park would "do significant harm" to the town centre's vitality and viability.
In performing that assessment the council "erred in a material way" in giving excessive weight to the larger area of comparison floorspace permitted by the extant planning permissions. Bridges Antonine argued that there was "no real prospect" of those permissions being implemented further.
The judge said: "The existence of permission for comparison floorspace on a greater scale than that applied for did not inform the council whether the 4,599 square metres applied for would 'protect and enhance' the development of the retail role and function of Cumbernauld Town Centre. Nor would it tell them that no detrimental impact would be caused to its role and function.
"The existence of the extant permissions was capable of no more than demonstrating that the impact of the proposal would be less than that already consented.
"Cumbernauld town centre in its retailing role had challenges of vacancy issues and contracting retailing...the existence of the extant permissions does not show that the development of the retail role of Cumbernauld town centre will be protected and enhanced by the proposal."
Although the local plan required a "full retail assessment" of all retail and leisure proposals of more than 2,500 square metres outside existing town centres, there had been no such assessment in relation to the comparison floorspace element of the scheme.
The judge concluded: "The reasons advanced by the council for the grant of permission were perverse and inadequate. It is perverse to use as a justification for granting permission a method of assessment which is incapable of meeting the requirements of the relevant policies."
The planning permission was quashed.
Bridges Antonine LLP v North Lankarkshire Council. Case Number: CSOH 38