Ventilated floors are a highly energy efficient solution. Ventilated space under the floor lets you freely select insulation thickness. Efficient ventilation below the floor structure also helps control the effects of moisture. Find the requirements for these in your national building codes. Cover the ground with plastic foil or insulation to reduce the amount of moisture underneath. Insulate the foundation from both sides. Install frost insulation in ground around the house to keep the whole structure from freezing. 

Make ventilated concrete floors with hollow-core slabs. Install the insulation on top of the supporting structure as follows:

Concrete floor, step sound
  • Flooring material
  • Reinforced concrete floor slab
  • Casting protection
  • Thermal insulation: PAROC GRS 20
  • Supporting structure: Hollow-core slab
  • Ventilated space