The council claimed that the impact of the extension had to be compared with the 125m2 floor area of the dwelling that originally stood on the site at 1 July 1948. The current property was a later replacement with a floor space of 222m2 and the extension would add almost 27m2, resulting in a 199 per cent increase in floor area compared with the original. This disproportionate addition conflicted with local plan policy and PPG2, it argued.
The appellants cited various court judgements including Sevenoaks District Council v Secretary of State for the Environment and Clarke  and Ascot Wood Ltd v Secretary of State for the Environment, Transport and the Regions and Churley . They asserted that the impact of the extension should be assessed by reference to the existing dwelling rather than the original one in the context of paragraph 3.6 of PPG2.
The inspector concluded that the council was correct in assessing the cumulative impact of the extension against the dwelling that existed on the site in 1948. He held that a fellow inspector had misinterpreted the court cases to which the appellants referred in determining another appeal raising similar issues. The proposed extension would result in a building well in excess of the 130 per cent increase allowed for under the council's planning policies, he found. It was disproportionate and adversely affected the openness of the green belt, he ruled.
DCS Number 100-058-339
Inspector David Vickery; Hearing.