A heated space with controlled intermittent extract ventilation. Extract ventilation must achieve a minimum extract rate of 30l/s and be controlled according to the requirements for intermittent extract ventilation defined in AD F.

OR

An unheated outbuilding may also be acceptable, where calculations by an appropriate member of the Chartered Institution of Building Services Engineers (CIBSE), or equivalent professional, confirms that ventilation is adequate to allow drying in normal climatic conditions and to prevent condensation/mould growth.

Any fixings/fittings must be a permanent feature of the room or space.

"Code for Sustainable Homes Technical Guide November 2010"