France
Gaining approval for a conversion in France is difficult (**details required**).
As of 03 April 2020, conversions are now legally possible without requiring authority from the vehicle manufacturer (who almost always said no).
The normal Manufacturers weight specifications need to be respected to with-in +/- 10%. That is total and axle weights.
The conversion must not modify in any way the structure of the vehicule - ie: no cutting and welding. The kit needs to be a bolt in configuration, so reversing to ICE remains possible.
The Engine Management / Onboard Diagnostics requires to remain functionnal - no warning light malfunctions. More importantly, original ABS, Cruise Control, Brake assist etc needs to function as originally intended by the manufacturer.
Important (as of 10 April 2020)
- conversion kits need to be validated by the French Vehicule Testing Body, and be presented by a registered 'Retrofit' company with Civil and Professionnal liability insurrances (to mention a few) - cost for homologation is anywhere around 30 000€ or more!
- conversions can only be carried out by registered and certified fitters of kits (speciality garages)
- battery packs need to comply with EU/CE compliance, with an important mention to batteries manufactured by certified companies only - no home made systems (unless you are willing to pay the costs for certification). This poses a problem for recuperating modules and creating your own battery pack
The association AIRe has been working with the government to construct a 'legal and safe' environnement for conversions, and since the investments and homologation costs are extremley high, the business model is generally to homologate a kit for certain 'mass market' models, and carry out conversions on an industrial basis.
Some 'retrofit companies' are selecting the high end market, proposing kits 'from' 20 000€ to 30 000€ for small city vehicles.
Other requirements are almost identicle to the German prerequisites , which can be found on the Main Page / Legalities Menu.
However, EV Romania (here) have provided homologation services for a number of vehicles including the "Electric Vehicle World Tour" van.
In this video EVWT describe the process;