On the 27th July 2016 I attended an AECB event visiting a Passivehaus in the construction phase. I was a huge contrast to the Straw Bale build I had been at only days before. Whilst both can claim to be ‘stainable’ forms of construction; Passivehaus due to its high insulation, and low energy use over the lifetime of the building and high level of fresh air. Straw bale due to the high insulation, carbon dioxide locked into the building materials themselves, and the use of natural materials that promote a health environment.
Notice the extra level of detail / components / chemicals involved in achieving a higher level of air tightness. Only to then be reliant on mechanical ventilation….. Whilst it is true that you save energy during the heating of finished building. I can’t help but wonder about the all the embodied energy involved in the construction phase. How would it compare to that of a Straw bale building? Though in theory the straw bale is going to be slightly less efficient in terms of heating of the finished building. It does however have less embodied energy during the construction phase, and could be argued actually locks up carbon dioxide during the construction phase.
Unfortunately I don’t have the figures, but I would also be very interest to learn of the cost comparison of a Passivhaus vs a straw bale house. I can’t help to think that the extra materials & level of detail required to achieve the Passivehaus standard are going to have an impact on your wallet.
Both have their merits, and people will always have their own preference to which they prefer. However I certainly know when one I would rather live in…