Insulation base plate / foundation

Hello,

I took some thermal images of our house and noticed that the foundation shows up quite warm in the images. The house is a prefabricated timber-framed house built in 1980 with underfloor heating and no basement. Is such a warm floor slab normal when using underfloor heating, or can it be reasonably insulated afterward?
Besides the floor slab and the two brightly glowing windows (they still have old window glass), do you notice anything else that could be improved?
Thank you very much for your help in advance!

Hello,

Is such a warm floor slab normal when using underfloor heating?

No, you probably have a thermal bridge there. Floor slab possibly not insulated....

or can this be reasonably insulated afterwards?

difficult without major effort

Besides the floor slab and the 2 brightly glowing windows (old window glass is still in here), do you notice anything else that could be improved?

to be honest, the pictures are quite small. Can't really see much.

Regards