This Phil. And the internal walls are probably mostly brick made from local clay. Which has a relatively high iron content in this part of the world. My house in Glasgow is 1850s and has similar wireless issues. My solution is to use repeaters that do most of the transmission vertically where the signal only has to go through the plaster and timber floors.

Should not be an issue .  I don’t actually know how stringent the rules are at track dsys/hill climbs , I need to look it up . 

I thought it was, but didn't want to embarrass myself in case my memory was failing 🤣 Interesting that you have had more success than me, I do wonder if that is related to property type maybe? I'm in an old early 18th century manse that is a) pretty large, and b) has a lot of sandstone walls throughout that do quite an effective job in blocking wireless signals of most kinds? I never get more than 12 months out of batteries, and often no more than 9. My system is out of warranty, but it works and I haven't found a comparable one yet!

Yes , the 6” one shown is hence why we are going to do a 4” version tucked further in . 

Looking awesome!    Stupid question probably but is that exhaust going to sit further out than the outside of the wheels?

"I run this in my house (and I recall there is another forum member here using it?)." thats me. probably had ours for about 10 years and its been very reliable, have only had one HR92 valve fail to work and got that replaced under warranty. Batteries last about 14~18 months depending on how much control they do. I now change them all once a year. You do get plenty of warnings when the battery voltage starts to drop.  Agree excellent system and does mean we just heat the part of the house we are using at the time. mike

Pretty radical conversion.  Car and garage!

I'm impressed with the level of restraint employed.  That must be one of your smallest hammers 

Not really a sensible suggestion, but if you look at 2.23 on this video, you'll see the chaps 2 post lift which also lifts the roof.  A metal deck roof on a frame would be well suited to moving up with the car, you just get a bit more ventilation when the lift is up.  The lift in the video must be rated to, or maybe just capable of, an impressive weight as that's not a regular SD1...  

That all sounds very sensible to me.  Couple of comments are that max surface temperature of most for finishes is 27°C 29 at a push.  This is not water temperature as there will be a temp drop through the screed, 40°c to the pipes is probably a bit high, but i suspect you mean 40°c to the manifold, where it will mix down.  Insulated floors are significantly less common than the EPCs would tell you, so you'll be ahead of the curve.  The first bit of insulation is the most important, it's diminishing returns the deeper you go. 20% saving is ambitious from a boiler, but if it goes from non condensation to condensation mode, you run the room at a lower temp, and you're adding insulation, you might get there 👍