Outdoor lighting and garden power

The single most common thing we are called to put right outdoors is a cable that was never designed to live outside — ordinary twin and earth stapled along a fence, or an indoor-rated socket in a plastic box on a shed wall. It works until the first wet winter.

A proper outbuilding supply is steel wire armoured cable, buried at depth along a planned route, terminated into its own small consumer unit in the building, with RCD protection and a circuit of its own back at the house. It is a bigger job than people expect and a much smaller job than they fear.

A garden room someone actually works in needs power, lighting, data and usually heating, and the load adds up quickly. We size the supply for what the building will really be used for rather than what it is called on the planning drawing.

We would rather put in one cable that carries the finished building than come back in two years because the original supply was specified for a shed.

Floodlighting a garden makes it unusable. The trick is layers: low-level light along paths and steps, uplighting on the things worth looking at, and enough control that you can have one without the other.

We plan the circuits and switching first, because retro-fitting control to a run of lights that were all wired together is the expensive way round.