Finding your way around the intricacies of the planning system without professional advice is, for most people, a near impossibility. The point was powerfully made by the case of a couple whose intimate living space was overlooked by a skylight fitted to a neighbouring property.

The couple said that the top-floor bedroom, study and bathroom of their home was so badly overlooked by the skylight that they could only get undressed by hiding behind a bookcase. Their neighbour periodically installed a mannequin in the skylight, giving the impression that there was someone there, watching.

The clear glass skylight, which could be opened, was fitted to a side elevation of the neighbouring property as part of a loft extension. A condition attached to planning permission for the works required windows in the side elevation to be non-opening and to be fitted with obscured glass. In reliance on that condition, the couple asked the local authority to issue a planning enforcement notice against their neighbour. The council, however, declined to do so on the basis that the condition only applied to a dormer window and not to the skylight.

Ruling on the couple's judicial review challenge to that refusal, a judge identified an ambiguity in the planning permission: a reasonable reading of the condition, which made no distinction between skylights and dormer windows, supported the couple's interpretation. However, design drawings that formed part of the planning permission pointed in favour of the council's arguments.

To resolve that ambiguity, the judge took account of extraneous evidence in the form of a planning officer's report, prepared before the grant of planning consent. Viewed in combination with the drawings, the report made it abundantly clear that the obscured glass and non-opening requirements were only intended to apply to the dormer window, not to the skylight. The couple's case was dismissed.