Ajn

We used British Gas (was three years ago) for the meter install (three phase) and as you say no problem. They even gave us £60 back when we had been asked "do you want a smart meter"? Then they realised no such thing was available at the time....

Crown are just an agent. Go direct to the DNO for supply and you need one of the main six to do the meter.

We had a similar issue but not listed and 200 year old walls. We built a structured concrete subfloor with ring beam. The timber frame was built off this subfloor but had a "boot" of DPC fabric around the base extending up the frame. DPC was layed on the subfloor then insulation then more DPC then the UFH then screed. We used the multi foil blanket and assoiated insulation product in the timber fame. We had various air gaps 50 - 300mm between the frame and original wall due to the wall being upto five bricks thick in places. Old buildings need to breathe as its the reason they have been around 200 years. We removed all traces of gypsom based repairs and repointed in lime. Because the insulation is in the frame the wall cavity can be vented out of the top under the tiles. We also installed some air bricks at the bottom but only one in each wall. Lime based walls are quite good at breathing on their own but the additional ventilation couldn't hurt. The original walls which sits on a simple limecrete foundation act like cladding for the structual timber frame. The building doesnt't have any gutter as the corbelling is very effective. There is no DPC in the wall.

If your roof is on your solutions maybe limited. We used the Actis three layer system. It was the only way we could maintain the roof profile (smaller rafters) AND have the purlins visable on the inside. The outer blanket is the pinned to the rafters by 25mm batten, then a further 25mm tile batten giving a 25mm air gap to the tiles. Between the rafters the Hybris honeycomb product is the clean and simple to install. Not so good if the builder thinks 400mm is the same as 410mm...The inside then has another blanket fastened with more 25mm horizontal batten. Std plasterboard is used pinned to the battens. Cables can be run in the 25mm gap and behind the battens as required. Thin led spots can go in the plasterboard and still have an air gap around them. Lots and lots of tape is ued to seal the inner blanket. As for price, while they don't supply direct we did get a good deal with them through our local supplier. This also translated into us getting a lot of other stuff from the supplier as we ended up as a trade customer. Another benefit is with all the aluminium foil involved in these profucts there is no chance of the alien space men getting you at night. I doesn't do mobile phone signals much good either.