Appeal judges reject 'reasonable observer' test for wind farm

The Court of Appeal has rejected a planning inspector's argument that a wind farm would not cause 'substantial harm' to the setting of a historic building because a 'reasonable observer' would know that it was a modern addition to the landscape.

Lord Justice Sullivan said that if this was the test, it was difficult to envisage any circumstances where a wind farm could cause serious harm unless it was in the "immediate vicinity".

The High Court last year quashed the inspector's decision to allow the building of five wind turbines near Lyveden New Bield, a Grade One-listed Elizabethan house and garden in Northamptonshire.

Giving judgment in Barnwell Manor Wind Energy v East Northamptonshire District Council and others [2014] EWCA Civ 137, Sullivan LJ said matters of "planning judgment" were for the inspector.

However, he said nothing in the planning guidance suggested that the question whether the harm to the setting of a designated heritage asset was substantial could be answered simply by applying the 'reasonable observer' test adopted by the inspector.

Sullivan LJ said a 'reasonable observer' would always be able to understand the differing functions of the heritage asset and the turbine array, and would always know that the latter was a modern addition to the landscape.

"Indeed, applying the inspector's approach, the more obviously modern, large-scale and functional the imposition on the landscape forming part of the setting of a heritage asset, the less harm there would be to that setting because the 'reasonable observer' would be less likely to be confused about the origins and purpose of the new and the old.

"If the 'reasonable observer' test was the decisive factor in the inspector's reasoning, as it appears to have been, he was not properly applying the policy approach set out in PPS5 and the Practice Guide.

"If it was not the decisive factor in the inspector's reasoning, then he did not give adequate reasons for his conclusion that the harm to the setting of Lyveden New Bield would not be substantial."

Sullivan LJ dismissed Barnwell Manor's appeal. Lady Justice Rafferty and Lord Justice Maurice May, vice-president of the Court of Appeal's civil division, agreed.

Robin Green, barrister at Cornerstone Barristers, represented the council, English Heritage and the National Trust, together with Morag Ellis QC. He said the ruling was important for everyone interested in the country's heritage.

"The Court of Appeal has confirmed that, in considering whether or not to grant planning permission for development (not just wind farms), decision-makers must give considerable weight to any harm caused to a listed building or its setting."