It’s getting real, folks! Last week Bozeman Cohousing members convened for not one but two marathon “Design Development Workshops.” Our amazing architects from Studio Co+hab brought the details large and small into focus. The drawings are almost final, and we’ve reviewed their recommendations for everything from roof trusses to door handles–in all over a hundred separate components in the common house and private homes.
Now I can much more vividly imagine myself working in the kitchen of the common house, enjoying the glowing afternoon light. An induction stove begins heating water for the pasta the moment I turn it on. While we slice veggies at the bamboo-topped kitchen island, kids play in the room next door. When the meal is over, cleanup goes quickly as we feed dishes through the industrial sterilizer. We mop the Marmoleum floor and we’re done. Going home, the recycled carpet keeps our toes warm, and my wife, Jodi, can play her viola without disturbing our neighbors, thanks to a sound dampening system in the floors and extra insulation in the interior walls.
Underneath all these materials and finishes, the defining characteristic of our new neighborhood will be mostly invisible when we move in. That’s because state-of-the-art energy efficiency technologies and constructions methods permeate the entire design. The overall goal the community set was “Net-Zero,” which is a fancy way of saying, “We want our buildings to have the smallest possible carbon footprint, all the way down to none.” That is, after all the energy goes in and out, there is minimal ongoing fossil fuel use.
Four major aspects of the planned design and construction aim to get us as close to net-zero as we can given our necessarily finite budget.
First, the Bozeman Cohousing buildings will be all-electric. That’s right, no natural gas will be used or available in the future. Even though our utility provider, Northwestern Energy, is being slow to transition the 40% of its generation currently coming from fossil fuels (looking at you, Coalstrip), as the grid eventually and inevitably moves to all renewable energy, our energy use will become renewable instead of locked to a fossil fuel infrastructure. Not burning fossil fuels for heating and cooking can also significantly improve indoor air quality in our homes.
We want our buildings to have the smallest possible carbon footprint, all the way down to none.
Second, we expect to have full photovoltaic installations on all the buildings as part of initial construction. These solar arrays will be fed into the net-metering system that sells excess power back to the grid, and all of the homes will share the savings in power costs.
Third, the home designs fanatically reduce the need to consume energy to begin with, following the Passive House standard, which defines how to make a home consume minimal energy for heating and cooling. Along with double pane windows and maximal insulation in the walls, floors, and ceilings, each building’s exterior envelope, or skin, will be completely sealed using the AeroBarrier system to prevent drafts. Just like spraying a sealant into your flat tire to patch the hole, AeroBarrier fills even the littlest gaps in the outer walls before the inside is finished.
Also, a thorough analysis of the natural light in every space helped the architects adjust window and solar tube placement to minimize dependence on artificial lighting during the daytime. When it is needed, all built-in lighting will be LED, using a fraction of the power and being much more durable than even compact fluorescent fixtures.
Finally, the mechanical systems will also be as efficient as possible. Heating and cooling with heat pump technology is just the start. Even our clothes can be dried and our hot water can be heated with heat pumps. And a heat recovery ventilator will circulate fresh air from outside, but use the stale air leaving the house to heat or cool it as it leaves. What’s all this fuss about heat pumps? In essence, they move existing heat from one place to another — either from a hot place to cool it down, or into a cold place to warm it up — without burning additional fuel to generate more heat. We don’t just have to obey the laws of physics, we can take advantage of them, too, and it turns out this is extremely efficient.
Taken together, these thoughtful designs and sophisticated features will help us reduce our energy consumption to the bare minimum. When we’ve put that much effort into sustainable construction, why not be recognized with LEED certification? We decided that the time and money required to be formally LEED certified would be better used in actually making our homes efficient and sustainable, and Studio Co+hab has certainly delivered. The designs actually do incorporate several LEED standards around daylight, material choices, and indoor air quality. And of course the net-zero goal is an objective target rather than a vague aspiration.
Now we really can’t wait to move in.