Wet underfloor heating designed, clipped out and pressure tested, then screeded over by the same team on the same visit. No handover between two firms, no argument about whose pipe got damaged, one price for the whole floor.

Pipe centres and circuit lengths worked out room by room from the heat loss, not laid to one spacing throughout and hoped for. Cold corners come from lazy set out.
Manifold position, circuit balancing and labelling done so the system can actually be commissioned and, years later, understood by whoever is servicing it.
Every circuit is pressurised and left under pressure while the screed goes down, so a damaged pipe is found before it is buried rather than after.
The pipes and the screed are one job with one team, which is the single biggest reason floors like this go wrong when they are split between trades.
Boiler, heat pump or a hybrid. Low temperature systems in particular suit underfloor, and the design is set up for the heat source you actually have.
The proper heat up profile after the screed has cured, brought up slowly so the floor is not shocked before a covering goes on it.
It usually is, because it works at a much lower flow temperature over a much bigger surface. That gap gets wider with a heat pump, where the lower the flow temperature the better the efficiency. Where it does not pay off is a badly insulated floor, so the insulation under the pipes matters as much as the pipes.
Yes, though the floor build up decides how. Where you can dig out or lose some height, a normal insulated build up with screed over the pipes is the best answer. Where you cannot, low profile systems exist that add very little height. It is worth getting someone to look at the floor rather than guessing off a website.
Same rules as any screed, and it must not be heated early. A liquid screed can often take a covering in a week or two and a traditional screed will take longer, then the heating gets brought up slowly through a proper commissioning cycle. Turning it on hard to speed things up is how you crack a floor.
Tile and stone are the best conductors and the natural fit. LVT and engineered wood are fine provided the manufacturer allows it and the surface temperature is limited. Thick carpet and heavy underlay work against you. Tell us what is going down at the quote stage and the design accounts for it.
It is very rare, because the pipe is continuous within each circuit with no joints buried in the floor, and every circuit is pressure tested and left under pressure while the screed is poured. That test is exactly what stops a buried problem.
Based in Bolton, working across the North West as a matter of course and taking planned work anywhere in the country.