Hi,
wondering if someone can point me in the direction of some information and hopefully diagrams.
I have extended my entry area, this was done by laying a new concrete foundation, with isopor underneath, plastic dampsperre and armering.  It is an 'inverted cup' foundation as I extended the walls and roofed over to give myself a larger entry at the cabin.  As there was a height difference between the floor level of the hytte and the ground outside, I gave instructions as the desired height of the new foundation and explained that it would be built over and later have varmekabler installed.  It is thicker (deeper) on the sides (load bearing) but only 10cm thick for the main area of the 'plate'.  There is also jackopor laid in the ground around the new foundation horizontally in the ground to stop frost.  The cabin is in the Geilo area.
After the construction was complete I then had an electrician lay varmekabler over this foundation and an area inside the hytte, so there are 2 different thickness foundations under the varmekabler.
The thermostat is placed near the new entry door, that is, over the new foundation.
I have noticed that even after a few weeks, the area over the new foundation is markedly colder than the area over the existing floor inside the 'old' part of the hytte.
I carried out the work of pouring the self levelling cement and tile-work.  Also the construction over the new foundation (walls, door and roof and interior).
I am wondering if there is a reason for this or if I have missed a step in the construction process?
I was 'bygg-ansvarlig' for the job, but hired in a local vaktmester company to carry out the foundation work.  The contract I have states that I am byggeansvarlig and that I had the option to approve the work before payment.
The work was carried out over a year ago and I have paid the faktura.  There is no structural problem with the work, but with the new area not warmng up to satisfaction, I have requested a refund for the cost of the varmekabler installation and tiles.
The vaktmester who carried out the work has told me that I should have laid a thin layer of isopor over the 2 different areas to equalise the thickness of the foundations so that the varmekabler had the same mass to warm up before laying the varmekabler.