Crystal clear

An inspector has rejected a householder’s claim that the application of opaque film to a new window in a side gable qualified it as permitted development (DCS Number 400-031-232).

The appellant argued that the matters alleged in the council’s enforcement notice did not constitute a breach of planning control. The notice, the inspector recorded, attacked a large window. He determined, firstly, that installing the window was a building operation materially affecting the external appearance of the dwelling and falling within the statutory definition of development. He explained that, whilst such an operation can be permitted development, that is conditional on the use of obscure glazing where, as in the case before him, the window is in an upper floor of a wall or roof slope forming a side elevation of the dwelling (GPDO Article 3, Schedule 2, Part 1, Class A, condition A.3 (b)). 

An opaque film had been applied over clear glass on the inner side of the lower part of the window. The inspector ruled, however, that it was patently not the same as the window being obscure-glazed, as the glass itself remained transparent. He noted no firm evidence to show that the film was permanently affixed to the glass. He reasoned that whilst the film currently restricted inter-visibility, it was not an integral part of the glazing, being an addition to the window not entirely unlike curtains or blinds in terms of its effect and similarly, therefore, being capable of removal. 

The inspector reasoned, further, that the Government’s Technical Guidance, which assists in interpreting the permitted development rules, advises that to satisfy the condition of permitted development such windows should be obscure-glazed to a minimum of Level 3. The absence of any reference in the TG to using opaque film reinforced his view that it is the transparency or otherwise of the glazing itself which is the relevant factor for determining whether the condition is satisfied, not whether it is possible to see through the window. 

The inspector concluded that the window did not satisfy the condition of permitted development. It followed that the window was in breach of planning control. 

The permitted development classes are set out at section 4.342 of DCP Online.