Planning electricity for a shed, garage or garden room

A garden building used for storage needs something different from a workshop, office, gym or future EV charging point. Planning the actual use first prevents an undersized supply or unnecessary work.

Start with the expected loads

• Lighting and general sockets
• Electric heating or hot-water equipment
• Office and data equipment
• Power tools or machinery
• Outdoor lighting, pumps or specialist equipment

Tell the electrician what may be added later. A small allowance for sensible future use can be easier to include during the original work than after paths and gardens have been reinstated.

Choosing the cable route

Surface, overhead, ducted and buried routes each have different access and protection requirements. For buried work, agree the ground type, route, depth, trenching and making-good responsibility before the quotation. Never begin digging until underground services have been considered.

The existing property supply

The main installation must have suitable capacity, earthing and protective arrangements. The distance, voltage drop, fault protection and outbuilding construction all influence the design. Metal buildings and installations with uncertain earthing need particular care.

What helps with an initial assessment?

Provide approximate route length, photographs of the closed consumer unit, proposed route and building, plus a list of intended equipment. Complex groundworks, long routes, machinery, hot tubs and EV charging should be reviewed individually rather than priced from a simple standard allowance.