External insulation- has anyone got a company to quote? Also heat exchange ventilation.

[starpatch]

So just that I am contacting companies at the moment to quote for external insulation but none have got back to me. Am in Kent and it would be a bonus if they could fit windows too. Am also looking for someone to quote for heat exchange ventilation. Thanks

Yes, for external wall insulation. They're actually doing it right now, so I'm keeping my fingers crossed it makes a difference. I'm in South East London, so not too far from you.
It was a while ago now (there was a very slow planning application delaying us). But I remember finding it tricky. Insulation specialists seemed only interested in council/commercial work. In the end I think I searched for external rendering companies and checked their website to see if they did insulation. A few companies responded, but I only ended up with one quote in the end.
We had new windows put in beforehand (the old ones were knackered) and got an extra 10cm on the sills to accommodate the width of the insulation. Someone who knows their stuff recommended installing windows at the same time, so they are flush with the insulation rather than wall. But I couldn't pull that off. So hopefully I won't live to regret it.
I've got internal wall insulation installation booked for the front of the house (slow planning permission failed) and I found it even harder to find people who do that!