EV Charging Site Survey: A Step-by-Step Guide

An EV charging site survey is the essential first step before any installation. It replaces guesswork with a clear, costed plan for a safe and future-proofed system.

Step 1 — Understand the requirement

Establish how many chargers are needed, at what speed, for whom (staff, visitors, fleet, residents), and the expected usage pattern.

Step 2 — Assess the supply and capacity

Determine the incoming supply rating and the site's existing maximum demand, then calculate the spare capacity available for charging. This capacity assessment decides whether load management, an upgrade, or both are needed.

Step 3 — Check the earthing arrangement

Identify whether the supply is TN-S, TN-C-S (PME) or TT, and design the required open-PEN protection for PME supplies (see earthing considerations).

Step 4 — Review the board and routes

Assess the distribution board capacity and protection, and plan cabling routes and containment to the charger locations.

Step 5 — Design and cost

Produce a design to BS 7671 Section 722 — chargers, protection, load management and any upgrades — with a clear cost and a path to expand later.

Step 6 — Install, certify and plan maintenance

Install with a competent contractor, certify the work, and set up a maintenance and (where relevant) OCPP management plan. A good survey makes everything that follows straightforward.