Energy efficiency survey to give advice on advanced insulation measures, who can I ask?

[starpatch]

Hi lovely mumsnetters, I would like an energy efficiency survey, not the sellers one which is a bit basic, but someone who can really tell me my homes weak points, can I reduce ventilation and would insulated cladding work for my house. Google isn't much help on this. Has anyone used a company that was good?
Many thanks

Sorry to answer my own post just found using the search function that SiulaGrande posted this company on another thread. This company only serves Sussex though. So if anyone knows a company that works in Kent would in interested. Thanks SiulaGrande.

bhesco.co.uk

Community energy england also has some useful information.

communityenergyengland.org/