We opted to go with Internorm and Redfen Associates in Norfolk, the whole experience was horrendous, we were completely mis-sold and our install costs went from £3000 in the outset to over £11000. On the back of a host of broken promises from Internorm and Redfen this was a huge blow to my family and I. Tread very carefully it's clear Internorm do not vet their sales partners, hopefully other manufacturers are more focused on quality and who is actually representing their brand. My story is a long and very painful one but feel free to message me I may be well placed to help you avoid the pitfalls having been wrapped up with a cowboy supplier.