I have no idea how this sort of thing works in the UK, but the two possibilities that leap to mind for are:
1. Create an SCI where your friend purchases a number of the shares in the property.
2. If you are of retirement age or thereabouts, look into a "vente en viager" - which is basically a "reverse mortgage" (as it's called in the US).
Talk to a notaire (or take a look at the material - available in English) on the notaire website:
Retrouvez toutes les informations sur les services notariaux, les conseils juridiques et les démarches proposées par les Notaires de .
www.notaires.fr
You can at least determine whether either arrangement might accomplish what you are looking for.