Loft conversions in East Sheen & South West London

What a loft conversion involves

Most loft conversions start with scaffolding and a temporary roof or protective sheeting, so the house stays dry while the roof is opened. New floor joists and any steel beams go in first, then the dormer or new roof structure is built and made weathertight. Inside, the new staircase is installed, the space is insulated, plasterboarded and wired, and any bathroom is plumbed in before decoration.

Because the heavy work is done from the scaffold, the floors below are often only disrupted when the new staircase is connected at the end. Most dormer and hip-to-gable conversions take roughly eight to twelve weeks on site; mansards and more complex roofs take longer. You receive a written programme before work starts.

Planning permission and permitted development

Many rear dormer and hip-to-gable conversions on houses can be built under permitted development, provided they stay within volume limits, don't face the road and use similar materials to the existing roof. Mansard conversions, front dormers, flats and houses in conservation areas or under Article 4 directions usually need planning permission. The current rules are on the Planning Portal, and a Lawful Development Certificate confirms that a permitted development scheme is lawful.

Building Regulations, fire safety and party walls

Every loft conversion needs Building Regulations approval. The key points are the strength of the new floor and roof, a safe staircase with enough headroom, insulation, and fire safety. Adding a storey changes the fire escape route, so the stairwell usually needs fire-resisting protection and interconnected smoke alarms.

On terraced and semi-detached houses, steels are often supported on the party wall, which means serving notice on your neighbours under the Party Wall etc. Act 1996 before work starts. The government's Party Wall guidance sets out the process.