We are very close to having a final floor plan. Our designer is busy working on the complete set of drawings to submit to the county when we get home. We are both excited about where the house plan is going but we are also surprised to see how different it is than what we originally imagined.

Some of the changes are small- no wood stove, patios instead of decks, more substantial loft space- and some of the changes are so big that we hardly recognize where we started. For one thing, our straw bales have turned into wood framing and stucco. It's not typical wood framing- the studs are offset to block thermal leaks and it will be super insulated with recycled cotton or special integrated panels. The move from bales was a tough transition for me though. I love straw houses: they are natural, renewable, they breath, insulate, provide thermal mass with the ideal time constant and they create such cool, perfectly imperfect, massively thick walls. But, in our search for a design and build team with expertise in passive solar heating and cooling, we came across a team who we really meshed with and who share our larger goals but who have come to embrace the Passivhaus model. Ultimately this is in line with our wants (to have a house that is designed to heat and cool itself without a large input of energy) but it is also a bit higher tech than we had in mind at the start and is not compatible with straw bale. We've been feeling alternately excited by the high performance we expect and put off by needing ventilation systems and expensive specialty building techniques that constrain other choices. The energy modeling that was just performed on our design is giving great results. In the heat of summer (which is the toughest season for our sunny exposed location), our house should only change by 4 degrees! With such low heating and cooling requirements, it will be easy to put up a minimal PV array and achieve net zero energy use. No utility bills!

Another surprising reality check came from our plan to save money by going super minimalist and industrial. Some ideas in this vein were to use a concrete slab for flooring, leave pipes and plumbing and beams exposed, have no shower enclosure (just a drain in the same concrete floors that cover the rest of the house), put the second shower outdoors, and use salvaged bricks and wood for walls. Some of these ideas are still being incorporated into the house but it turns out they don't provide much, if any, cost savings. The slab requires a bit more earth moving which ends up breaking even with the cost of wood flooring over a perimeter foundation. We are going with the concrete floors anyway because we like them and they add a great thermal mass but they are not the big simplification that we hoped they would be. We have to add a shower floor anyway. It is *more* expensive and complicated to use the slab itself. Who would have guessed?! Exposing the pipes and wires requires nicer metal pipes and conduits (more expensive!) and a loss in effectiveness by running up against gravity instead of down through the slab. There are a few places where it makes sense to leave conduits exposed and we will take advantage of those spots but there aren't many. We will leave quite a bit of interior framing exposed to achieve some raw open beam feel but it turns out sheet rock is awfully cheap and so the choice is more about aesthetics than budget. We will still use as much salvaged finishing wood and fixtures as we can but the salvaging process is still a big unknown to us. I hope we find some cool stuff. Here was another surprise- an outdoor shower isn't compatible with an energy efficient house (heat escapes through the shared plumbing) and so we would actually need to use the outdoor hose plumping and put an on demand water heater outside. The imagined simplification of sticking a shower head outside over some rocks becomes a complication with additional cost instead. We may add this later because I would really love an outdoor shower but the idea was much more appealing when we thought it was a cool way to save money by roughing it a bit.

So, our straw bale, creatively economical, minimalist house has evolved into a higher tech, more mechanical, less natural, and not particular economical house (well, not to build anyway- it will be economical long term with no energy bills). Even with all of that, there are major parts of the plan that haven't changed: our house will be extremely well designed for passive solar temperature regulation, it will have a very open interior with concrete floors, it will be smoothly connected to expansive outdoor living spaces, it will be super functional and flexible in how we can live in it as our lives change, and it will be even more efficient than we had imagined.