Why Use the Passive Slab?

Eliminates Thermal or Cold Bridging

The Passive Slab will eliminate the Thermal Bridge that occurs where the floor element meets the wall element of the building.The focus on insulation has grown significantly over recent years and with this more and more people have increased the amount of insulation they are putting into their floors, walls and roofs. We are very much focused on the more is better approach, one that we very much support. However, as we look at increasing the amount of insulation installed in our homes we must not lose sight of the other weak links in our buildings when it comes to heat loss. Any point in a building where there is a break in the run of insulation is called a Thermal Bridge. This is also commonly known as a Cold Bridge.

A Thermal Bridge is most common at the junctions of a building. A typical junction is the point where the floor meets the walls or where the wall meets the roof. If great care is not taken to minimise this thermal bridge the problem is exasperated, particularly when we increase the insulation levels throughout the building. Increasing insulation levels essentially makes the cold bridge colder leading to increased condensation and mold growth at the junction.

The Passive Slab solves this problem perfectly as there is no thermal bridge at the point where the floors meets the walls. The entire junction is wrapped in insulation lowing the U-value and improving conditions inside of the building.

Floor U-Value Improvement

The Passive Slab offers the lowest U-value (0.08W/m2K) for a floor system currently on the market in Ireland. A typical traditional build home in Ireland must achieve a U-value of 0.25W/m2K for floors with no under floor heating and 0.15W/m2K for floors with underfloor heating. Taking the 0.15W/m2K figure, when we include the Thermal Bridging Factor in our calculation the actual U-Value of the floor is 0.37W/m2K, a figure significantly higher than the requirements of Building Regulations Part L 2007. As the Passive Slab eliminates the Thermal Bridging issue the stated U-values are as achieved.

Improve Underfloor Heating Performance

Studies have shown that the heat loss through rising wall from underfloor heating accounts for 65%. The Passive Slab reduces this figure to 12% heat loss, improving the efficiency of the heating system and saving on fuel costs. Again this improvement is due to the elimination of the critical wall to floor Thermal Bridge. 

Cost Comparative to Traditional Foundation System

The Passive Slab is a complete Foundation System that is used as an alternative method to Traditional Foundation systems typically installed in Ireland and the UK. The Passive Slab system will accommodate all building building types including the KORE Insulated Concrete Formwork (ICF) System. When compared with the costs of installing a Traditional Foundation System our clients find very little in the difference. That's the great thing about the Passive Slab system, it as all the benefits of a Passive house achievable within budget.