Passive House + Zero Net Energy + Permaculture
My wife and I decided to try and build a Passive House* in 2014 when we moved closer to her work as a school teacher. After some major glitches with our original builder (this is a huge understatement: see The Passive House Nightmare section above for details #ripoffclause), we are trying to move forward, and we hope to start building some time in 2016.
We also hope to do a significant amount of permaculture design in our yard, and we wanted to share the process as the structure of the house and the yard develop over time.
I will also try to share resources we find helpful along the way as well.
*Passive House (Passivhaus): initially a German-based building standard, now a way to build residential and commercial structures that is growing every year, mainly in Europe and North America.
The basic principles are:
- Create an airtight building envelope (0.6 ACH is the goal — current codes typically allow 3.0 ACH or higher).
- Use significant amounts of insulation (sub-slab, exterior of foundation, walls, and attic) to dramatically increase R-values above most current code-built structures (also use Passive Certified windows and doors, and try to eliminate, as much as possible, all areas of thermal bridging).
- Constant ventilation via either an ERV or an HRV, which are efficient air exchangers that can hold on to either warm (in the winter) or cool (in the summer) conditioned air. Typically this is combined with ductless mini-splits (heat pumps) for heating and air conditioning.
The goal is to dramatically reduce the energy demands of the structure (by 80-90% is the typical claim for heating and cooling), while creating a more comfortable living space: Higher R-values surround the structure like a thermos (warmer in the winter, cooler in the summer). Constant, but also filtered and balanced, incoming and outgoing air streams, and low or no VOC building materials and finishes work in concert to produce and maintain a high level of indoor air quality (IAQ). Certain houseplants can also make a significant contribution to indoor air quality: Kamal Meattle.
Once the energy demands of the structure have been radically reduced (this includes HVAC, lighting, heating water, and plug-in loads), a building standard such as Net Zero — aka: Zero Net Energy (ZNE) — becomes relatively easy to achieve. If successful, the structure will produce at least as much energy as it uses (in some cases even a surplus can be produced).