Part S EV Charging Calculator

Establish which requirement applies and, above all, which parking spaces are associated with the building. That is the input most likely to be wrong, and Diagrams 1.1 and 1.2 of Approved Document S exist for that reason. A space is associated if it is within the site boundary and for the use of the occupants or users of the building. A space beyond a public highway or on someone else’s land is not. Some garages contain no parking space at all.

S1 for a new residential building, S2 for a material change of use creating dwellings, S3 for a residential major renovation, S4 for a new non-residential building, S5 for a non-residential major renovation, S6 for mixed use. The tool then asks only the questions that requirement needs. S3, S4 and S5 are engaged only where there will be more than 10 parking spaces.

Associated spaces, how many of those are in a covered car park, and how many dwellings the parking serves. Paragraph 1.1 sets the residential requirement at the lesser of the spaces and the dwellings, so a house with two spaces on the drive needs one charge point, and a block of 10 flats sharing 4 spaces needs four.

Charge points are not required in a covered car park. The requirement is met by putting them in the spaces that are not covered first, and cable routes then make up the rest of the total. Where every space is covered, no charge point is required at all — but cable routes still are, and for a residential building with more than 10 spaces that means every space.

The £3600 average connection cost cap applies to new residential work. To rely on it, paragraph 1.7 requires at least two formal quotes at notice or plans stage, at least one from a distribution network operator, and you enter the maximum number installable within the cap. The 7% cap applies to major renovations: under it everything applies, over it the charge points fall away but cable routes remain, and over it even for cable routes alone nothing is required.

Enter what the drawings show and the tool says whether it is enough. A charge point may serve more than one space provided all those spaces can be used for recharging at the same time, so count outlets rather than enclosures. Where the building has accessible parking, paragraph 6.4 requires at least one accessible space to have a charge point or a future connection location.

Approved Document S gives no guidance on electrical or fire safety. Approved Documents B and P, the Electricity at Work Regulations 1989, BS 7671 and the IET Code of Practice all apply to the same installation. Whether the incoming supply has capacity, and what a distribution network operator will quote, are matters of evidence the tool cannot establish.

The PDF needs your name and company. It records the requirement, the regulation, the working and the full specification for charge points and cable routes. Save inputs writes a .briaryev file. For problems, email toolsuite@briary.co.uk.