The KORE Passive Foundation is an insulated foundation system (passive foundation) that works much like a raft foundation. It is used for the construction of ground floors. The KORE Passive Foundation offers the following benefits:

KORE Insulated Foundation Technical Benefits
  • Meets and exceeds Ireland's Building Regulations
  • Eliminates the critical wall to floor cold bridge (thermal bridge)
  • Reduces underfloor heating loss from 65% to 12%
  • Reduces the quantity of concrete needed for the foundation by up to 50%
  • Suitable for all ground conditions while easily accommodating a radon barrier
  • Eliminates the risk of condensation, fungus and mould growth behind the skirting board
  • The thermal capacity of the Passive Foundation will not diminish over time and is not affected by water
  • Easy to work with and install
  • Exceptional compressive strength makes the product suitable for both domestic and commercial applications
  • It's suitable for use with underfloor heating systems

Read more about the benefits of using an insulated foundation system.



The following are sample U-value calculations for KORE's Insulated Foundation System. For more examples please download the Insulated Foundation System Design Guide or contact our technical team for a detailed U-value calculation specific to your project.

Calculation Assumptions

All U-value calculations are in accordance with BS EN ISO 6946:2007. Ground floor U-value calculations are different from wall and roof calculations in that reference to the construction detail alone is not sufficient to calculate the U-value. The floor area and perimeter of the external wall and the thickness of the wall must be known to calculate floor U-values correctly. For more information on our calculation assumptions please reference our Design Guide.

Passive Foundation Detail: Blockwork Wall Foundation Double L

KORE Passive Foundation System - Double L


Insulation Thickness (mm)  Perimeter/Area (m2)      
  0.2  0.3  0.4  0.5  0.6  0.7 
 U-Value (W/m2k)      
300 0.09  0.10  0.10  0.10  0.10  0.10 


Passive Foundation Detail: Blockwork Wall Foundation Single L

KORE Passive Foundation System - Single L

Insulation Thickness (mm)  Perimeter/Area (m2)      
  0.2  0.3  0.4  0.5  0.6  0.7 
 U-Value (W/m2k)      
300 0.09  0.10  0.10  0.10  0.10  0.10 




The KORE Passive Foundation System should be designed by a qualified engineer. KORE does not design or inspect foundations. The information below is for general reference only.

The following standards should be consulted regarding the construction of floors:

  • BS 8215:1991 Code of practice for the design and installation of damp proof courses in masonry construction
  • BS 8102:1990 Code of practice for protection of buildings against water from the ground
  • BRE GBG28 Domestic Floors: construction, insulation and damp-proofing
  • BRE GG74 Radon protection for new dwellings
  • BS 6399-1:1996 Loading for buildings -  Code of practice for dead and imposed loads
  • BS 8203:2001 Code of practice for the installation of resilient floor coverings
  • BRE Digest Nos. 240, 241 and 242


Thermal Conductivity

The thermal conductivity of KORE Passive Foundation Insulation products are in accordance with IS EN 13163:2012 and EN12667 Thermal performance of building materials and products - determination of thermal resistance by means of guarded hot plate and heat flow meter method

  • KORE Passive Foundation EPS300 White: 0.032W/mK

Thermal Resistance

Thermal resistance, known as the R-value, varies with the thickness of the insulation. To calculate the thermal resistance (m2.K/W) divide the thickness of the insulation by its thermal conductivity and round down to the nearest 0.05.

  KORE Passive Foundation EPS300
Thickness Insulation (mm) Thermal Resistance (m2.K/W)
100 3.125
150 4.688
200 6.250
250 7.813

Declaration of Performance

KORE Floor EPS70 Silver
KORE Floor EPS70 White
KORE Floor EPS100 Silver
KORE Floor EPS100 White
KORE Floor EPS200 White
KORE Floor EPS300 White
KORE Perimeter Strips EPS70 Silver
KORE Perimeter Strips EPS70 White
KORE Perimeter Strips EPS100 Silver
KORE Perimeter Strips EPS100 White



KORE Passive Foundation - NSAI Irish Agrement Certificate Number 04/0097 for KORE Floor Insulation.

KORE Passive Foundation System is manufactured to BS EN13163:2012 under Quality System approved to EN ISO9001:2015 Quality Management.


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