underfloor insulation with little space

[Jan_Kropf]

Hi all,

 

We are currently refurbishing our house in Oxford.
We have a suspended floor with a concrete foundation under it. We want to insulate the floor and install UFH, however the ceilings are farily low meaning that I would want to avoid height build up of the floor as much as possible.

I lifted one floorboard and measured.
The joists are 80mm, there is another 80mm space below it.

Initially I had planned to install the insulation described here: https://www.ecologicalbuildingsystems.com/post/best-practice-approach-insulating-suspended-timber-floors

Using this approach, I would be able to add 80mm of insulation and there would be 80 mm of ventilation space remaining. 
Is this enough space for that plan to work? Both in regards to insulation for UFH and to the ventilation space below.

If not, what other possible solutions are there?
Would an insulated concrete floor make sense? If yes, how costly is that in comparison to the solution above?
 

 

On a separate note, we would also like to install UFH on the first floor. (I read a lot about UFH vs radiators vs nothing at all on the first floor. We currently think that we don't want radiators for aesthetic and space reasons and would like to avoid the possibilty that it gets cold there in winter.)
What kind of insulation would you install between the floors then? (We currently have 200mm space in that ceiling, but we need some of the space for plumbing, electricity and MVHR tubing.)

Many thanks,
Jan



Here the link to the introduction of our house in case you need more information.