Construction is well under way for this two-storey and single-storey extension. A rainwater harvesting tank has been buried underground, this will feed the washing machines and toilets. 150mm (50% more than needed for building regulations) of Knauf Earthwool has been put in the cavities and 275mm of Black Mountain Hemp insulation between and under the rafters. The roof is breathable allowing water vapour to escape through the breathable hemp insulation and breather membrane (instead of traditional roofing felt). The walls can’t be breathable due to the planning constraints that brick must be used, therefore the Earthwool is fine in this situation, made from recycled materials and formaldehyde free it is much better for healthy builders and the environment as well.
This space will be warm and full of light and make sense of an unfortunate extension made by previous owners. It will allow the family to live more towards the back of the house, making more of the garden.