saveasteading

Cement board will be stronger and provide fire protection.

I'm expecting that to be much more expensive.

Exactly so. The fire stopping is easy so we can look at that when you have decided on a simple route and the pipe and cable and insulation sizes. There seems to be eps exposed in the garage. Does that get protected?

You'll lose so much heat out of the side and top that it isn't a great concern. But I agree with @crispy_wafer, and you could score the boards to threepenny-bit principle to nearly a circle. Have you checked the insulation strength? If it squashes it becomes useless.

I don't agree. Air to water I think we all know about. Some of that is taken to a plenum to heat air which is pumped into the room and a duct returns it from the other end. Simple but prob not for the typical installer who buys a kit.

It's good enough to find them. Thanks muchly. S and B EPS. Their website is comprehensive on strengths and insulation, and some other products. But nothing on where to buy or costs, so I've sent them an email. Strangely the strength and insulation vary by thickness, presumably a manufacturing density thing. And they make consciously stronger stuff too. k = 0.036 average.

We had an office, now sold, that used air to air. It worked well and quickly in heating and cooling and suited the big open spaces as well as the small. But we didn't walk around barefooted. In a domestic situation I have no experience of barefoot winter use on an unheated tiled and well insulated floor. But the principle is simple enough. If the floor is 25°C or so from absorbing space heating then it won't suck heat from your feet, but that won't be an efficient process. That's the main issue I think. Ufh is inherently warm and gives you cosy feet then spreads to the air which can be cooler. I don't see any reason against having both, it's just heat transfer through pipes to the floor or to a fan.

2 at least are further north than that.

Windows do that.

Yes, but does the floor screed move or crack under the foot of Xander Fagerson? And will the tv packaging be strong enough?

This is getting into science fiction. I need a lie down. What is the cube root of time anyway? Or is it a way of proving that that entropy isn't what it used to be?

They have the best of the quoted prices online at present, along with Insulation Wholesale. Some others say they will match any quote but I resent that attitude and will tell them that they must quote their best price first as I don't give second chances. If they are too scared to do that then I don't fancy their service or security will be great either. What is the point of matching another quote unless their is some other benefit? @Susie was this recent?

I meant after a winter of the ground source pipes removing the therms. They look like this but with arms and legs: That needs an Ancient Greek letter. You mean deeper to the perimeter? It makes sense to have deeper insulation round the perimeter, and shallower to the middle, but that isn't happening. It's just going to be a less efficient area of the building, balanced by the centre of the slab being over-insulated. Perhaps PIR to full depth around the perimeter and 2 layers eps centrally is the pragmatic (and finicky) decision. It is intuitive rather than proven, but I'm confident I could write a page of 'proof' for the building inspector if it was necessary... but it isn't and will just be our decision.

We were discussing what to do with rooms that should be cool. Larder/ cupboard etc. and does the Utility room need to be warm? The current decision is to put the ufh pipes in anyway but not connect them, so we have full flexibility if (when) there is a revamp. I think the same logic can be applied to the whole house if ufh is a likely addition in future. If diy'ing the cost isn't great at this stage but simply wont be done at a future stage.

where, where, where please?