Guildford Borough Council v Secretary of State for Community and Local Government

In assessing whether a dwelling-house extension in the Green Belt is appropriate development, the decision-maker must apply the policy test concerning disproportionate additions over the size of the original building. The assessment is principally one of categorisation by size, but proportionality remains a matter of planning judgment. The decision-maker may also consider the extension’s effect on the existing building, openness, visual amenity and relevant local planning policies. A planning inspector’s decision letter must be read fairly and as a whole. The court should not infer legal error from an infelicitous passage where the letter, read in context, shows that the correct policy tests were applied. Consistent local planning decisions may be a relevant consideration in exercising planning judgment.

Guildford Borough Council challenged under section 288 of the Town and Country Planning Act 1990 an Inspector’s decision allowing an appeal by Simon and Carina Moffat against refusal of permission for a two-storey extension to their dwelling at Fallows End.

The property was in the Green Belt, an Area of Outstanding Natural Beauty and an Area of Great Landscape Value. Previous extensions had increased the original floor area from 149.4 square metres to 235.8 square metres. The proposed extension would produce an overall increase of 134 per cent over the original dwelling.

Guildford argued that the Inspector had failed to apply paragraph 3.6 of PPG2 and had assessed the proposal against the existing rather than the original building. The central issue was whether the decision letter disclosed an error of law.

1. The application was refused. The Inspector’s decision allowing the extension was not shown to contain an error of law. Guildford was ordered to pay the defendant’s costs of £6,379.
2. Under section 288 of the Town and Country Planning Act 1990, the court could intervene only on ordinary administrative-law grounds. The weight given to material considerations and matters of planning judgment remained for the decision-maker.
3. The decision letter had to be read in good faith and as a whole. Its reasons were adequate if they enabled the reader to understand the decision and its treatment of the principal controversial issues. Paragraph 9 was unfortunate, but it could not properly be isolated from the Inspector’s identification of the original and existing floor areas, his calculation of the 134 per cent increase over the original building, and his express conclusion that the PPG2 exception was satisfied.
4. Paragraph 3.6 of PPG2 required an assessment of whether the extension was a disproportionate addition over the original building. Following R(Heath and Hampstead Society) v Camden London Borough Council [2008] EWCA Civ 193, the first-stage issue was principally categorisation by size. The judgment also recognised that proportionality allowed planning judgment and common sense to operate. The relevant measure could include footprint, floor space or volume.
5. The Inspector also had to apply local policy H9, which required consideration of the proposal’s effect on openness and visual amenities and its size, scale, design, materials and character. Previous permissions for substantial extensions in the immediate locality were capable of being relevant to consistency and fairness in public administration. The Inspector was entitled to take them into account.

The judgment describes an Inspector’s decision dated 25 March 2009 allowing the interested parties’ planning appeal under section 78 of the Town and Country Planning Act 1990. The High Court dismissed Guildford’s statutory challenge to that decision.