Electricity to a shed: plan the route and equipment

This guide helps you prepare the brief and quantities. Have the fixed 230 V supply, protection, earthing and verification designed together. For modest lighting alone, a complete extra-low-voltage garden kit may offer a different option within its manufacturer's limits.

List the equipment

For each appliance, record its make, model, input power and intended position. Say which devices need to run together and whether heating or charging equipment might be added later. Include exposure to moisture, dust, cold and mechanical damage.

The load inventory adds known input powers. It preserves unknown items instead of counting them as zero. It cannot choose a circuit or cable size. Prysmian's cable guidance shows why route length and installation method matter alongside load.

Investigate before digging

Draw possible routes from the house. Mark paving, trees, foundations, drainage and crossings. Do not dig to a supposed universal depth found online; the installation method and site must be assessed first.

Mechanical excavation requires a KLIC notification. Kadaster explains the notification and utility information. Services can run through private land too. Drawings do not replace establishing the real location with the person undertaking the work.

Build a specification list

The agreed list should identify the supply cable, route protection, entries and glands, boxes, light fittings, switches, sockets, fixings and any work at the distribution board. Record who supplies each item. A Dutch grondkabel category is a starting point for finding a specified product, not a guarantee of suitability for your route.

Ask whether the exact cable is approved for the installation method. Appearance and cable family names are insufficient. Boxes and glands must form a suitable assembled system. An IP44 mark does not approve every outdoor position: Hager's IP44 range describes particular moisture and splash conditions.

For your preparation, have a tape measure, sketch, appliance manuals and access to the route. Buy cable and protective devices only after specifications are confirmed. Retail alternatives can then be compared against the same requirements.

A route-length example

A garden may be 12 metres long, while the route also includes 3 metres inside the house and 2 metres along the shed wall. That is 17 measured metres before agreed termination allowances or purchasing contingency. The calculator keeps these amounts separate. It neither selects the cable nor approves the route.

Agree who checks the installation before trenches or walls are closed and what verification and handover records you will receive. Keep a route drawing, product details and circuit description for later work.

Can an extension lead replace a permanent supply?

Do not turn a temporary extension lead into buried or concealed permanent wiring. A fixed supply requires an appropriate design.

Can I prepare the trench myself?

First agree whether this is suitable, and establish the route, utility information and working method with the contractor. Preparation must not prevent necessary inspections.

Discuss the shed supply with CAS. Include the equipment, route measurements and any preparation you hope to undertake yourself.