Abstract
This research analyses by means of the 3D finite elements method (FEM) the calculation procedures proposed by the standard EN ISO 13370:2007 for the slab on ground case. Different soils and floors have been studied, with different thickness, position of the insulation layer and aspect ratio. Both steady-state and dynamic sinusoidal external solicitations (daily periodic stabilised and yearly forcing temperature) have been considered for the simulations. The approach proposed by the standard has been assessed as concerns the geometrical aspects and the modelled yearly heat losses have been used to define proper boundary conditions for building simulation with the conventional tools.