Can you use the information and pictures on the Zappi website below;
(Zappi pictures on checkatrade which you can use also on our website).

Cost of basic Install:

Zappi & Harvey Hub £865.00p
Labour £240.00p
Cost £1,105.00p
EV Grant -£350.00p
Grant Cost £755.00p
20% Vat £151.00p
Total Cost £906.00p

If no surge protection or spare circuit on customers consumer unit another surge protection consumer unit will need to be installed at a cost of £478.68p see below.

Cost of new 4 way surge protection consumer unit installed including 10 metres OF 6mm twin & earth cable.

Cost £398.90p
20% vat £79.78p
Total Cost £478.68p

Note; No surge protection on a consumer unit and a power surge happens it can damage ev batteries resulting in thousands of pounds worth of car batteries.