Insulation

Insulation is one of he key elements of a Passiv Haus. By having really good insulation it allows the building to retain the heat that is generated within the house by activities (cooking, electrical goods, people's body heat etc.) and also via passive means (solar gain - heat from the sun).

The Cardiff house here has a timber frame structure with 200mm deep studs. Between the studs Isonat cotton/hemp insulation has been chosen to preserve breathability and also minimise oil based / high embodied energy products. 

On the outside of the timber frame 80mm of fibreboard will be added and then a mesh and render finish. This is another breathable and natural product. Altogether the depth of insulation will be approx. 300mm. This is still the average depth of a normal cavity wall construction, but it is packed full of insulation rather than reliant on a thin cavity with a non-breathing insulation and high embodied energy insulator like PIR foam.

Rounded Developments Enterprises can access both the hemp and wood fibre insulation and we have samples on display in the centre.