Slab-on-ground floor. Calculation of thermal transmittances. SS-EN ISO 13370:2007
Building width [m]
Building length [m]
Building area [m2]
Building perimeter [m]
Insulation thickness [mm]
Insulation lambda (thermal conductivity) [W/(m K)]
Floor slab thermal resistance (additional) [m2 K/W]
Wall thickness [m]
Type of ground
Unknown
clay or silt
sand or gravel
homogeneous rock
Perimeter thermal bridge design
No thermal bridge
Good
Fair
Poor
U-value [W/(m2 K)]
0
- for a complete building, P is the total perimeter of the building and A is its total ground floor area. - to calculte the heat loss from part of a building (e.g. for each individual dwelling in row of terraced houses), P includes the lengths of external walls separating the heated space from the external environment and excludes the lengths of walls separating the part under consideration from other heated parts of the building, while A is the ground-floor area under consideration. - unheated spaces outside the insulated fabric of the building (such as porches, attached garages or storge ares) are excluded when determining P and A (but the length of the wall between the heated building and the unheated space is included in the perimeter; the ground losses are assessed as if the unheated spaces were not present).