Under floor heating for a new home that I'm purchasing

CastleHill

I've exchanged contracts for a new build home Interested in UFH for the entire house. Ground and First.
Ground floor
already been screeded and hence cannot install pipes inside the screed
60m2
Finished height = 2385 mm
First
Wooden joists
60m2
Finished height = 2283 mm

What option would you suggest
A) Use water based over lay systems (Polypipe, NuHeat). This means my floor height could increase (min 18mm), which means I might have to refit the doors
Electric mats. Not sure how effective it will be especially with a huge area. Also understand the running costs are too high
C) Remove the screed and put the pipes below and screed again. This feels like a daunting was for me especially given that the house is a brand new one.

Any thoughts experts?

Silver-Surfer_2

Has the central heating already been first fixed?

So 18mm minimum downstairs, plus the finished floor on top of that. Has the kitchen downstairs loo been fitted yet?

Probably a non starter for this house, if you must have it then I'd either look at getting out of the current contract and buying another.

CastleHill

Yes, boiler is fixed

Furts

I second Silver-Surfer. In terms of work, cost, practicalities, selling on and all the detriment and problems you will cause with your NHBC (or similar) Warranty this is a non starter.