Jersey RdSAP Convention 3.09
Any foam or foil-backed foam product, such as Celotex or Kingspan, can have the measured thickness doubled due to the better thermal resistance of the material used.
With this example for external wall insulation, if the measured thickness of the insulation was 100 mm, it could be input into iQ-Energy as the following:
Multi-foil Insulation
Multi-foil insulation would be defined as a multi-layered blanket-type insulation which contains at least three layers of foil-type material, such as the example above.This type of insulation is often used in room spaces as rafter insulation.
As with foam insulation, the measured thickness of multi-foil insulation can be doubled due to the higher thermal resistance of the material.