A friend sent me a link to a story about “The Greenest Home in America.” Naturally, I was interested. But the second sentence assured me it wasn’t true: “The home, which is being constructed in Portola Valley, CA will be over 5,600 square feet...”I read on and was impressed with the owner’s commitment, but he fell off “The Greenest” pedestal by first deciding to build so much living space for so few people.
People who can afford it will almost always build larger homes than they really need. Too much money leads to too much building, which then makes it much harder to also create a home that is the paragon of green and sustainable. You can’t buy your way into the green pantheon because it’s more about absence than existence. You don’t buy the absence of space, things and amenities; it’s a free choice that’s about priorities and appropriate values. You can’t buy green without being green. You can, however, be more green by being less wealthy, thereby replacing free choice with no choice.
It would be possible to make a Hummer a hybrid, but it would never be “The Greenest Car in America.” The very Hummer idea is too wrong to everbe turned into an environmental virtue. A 5600 square foot home may be a nice thing to have, and I certainly applaud the effort to make it greener and more sustainable, but the greenest home in America? I don’t think so.
Our UnityHouse was an effort to build a home that was as green and as energy-efficient as we could manage with our resources. It earned a LEED Platinum rating and proved our intended Net-Zero performance. It’s a very good prototype for green, sustainable building, but we didn’t have the chutzpah, the arrogance, or the ignorance to make wild claims about it. In fact, one of our goals was to make a prototype of a type of building that ought to become standard. We wanted it to ultimately be unremarkable.
At about 1900 square feet, Unity House is nearly a third the size of the Portola Valley home. We achieved this even though, as the on-campus home for the Unity College president, it expands weekly to become a 30 student classroom, and several times a year it morphs into the meeting area for the college board of directors. We devised movable and demountable partitions to allow the building to flex instead of requiring it to grow.
Unity House has essentially the same type of green strategies, materials and energy efficient lighting as Portola Valley, but it has less of everything, which adds up to much less embodied energy in the building and much less energy demand from the building. Less begets less.
To provide heating and cooling (mainly cooling) for the Portola Valley home, they used a geothermal heatpump system and had to drill down 250 feet for the closed-loop water supply. The big building needed big geothermal cooling/heating capacity. That’s a lot better than resorting to a fossil fuel solution, but it’s very expensive to install and requires extra energy to propel the pumps and multiple circulators needed to keep the water flowing in and out of the ground. Geothermal heating and cooling is a good alternative, especially when the loads are relatively high, but its initial cost and on-going energy consumption are significant issues.
Because the Unity House is so much smaller, as well as being highly insulated and well sealed, we were able to use an air source heat pump system. Air source heat pumps are less than a third the cost of geothermal systems and use much less energy to operate because they don’t require big pumps and multiple zone circulators. Unity House heating and cooling loads were small enough to make a simpler, less expensive, and less energy-intensive air source system possible.
Even to the wealthy owners, the accounting of the energy loads on the Portola Valley building must have been a little bit shocking. To keep it powered by the sun instead of grid electricity, they installed a 21 kilowatt photovoltaic system. That’s an industrial sized solar array. It would typically have an installed cost of around $170K – $200K. We’ve built entire houses for less.
In comparison, Unity House needed a 5.2 kilowatt system, which was actually a little disappointing. We had originally estimated that 4 kilowatt system would suffice, but later calculations caused us to increase the size to ensure that our energy needs could be supplied by the sun, not the grid. We did make it to Net-Zero; therefore producing more energy than we used in the first year, but the margin wasn’t excessive. We needed 5.2 kilowatts.
While I’m proud about our accomplishment, I’m even more determined to do better the next time. I’m sure we can. But compared to the “Greenest Home in America,” we did great. Unity House is one third the size of Portola Valley, yet uses one quarter the amount of energy anticipated by the Portola owner–stats made even more impressive given that Unity House is in the grey, cold interior of Maine and the Portola Valley house is in the sunny, balmy, San Francisco Bay area of California.
So does this make Unity House “The Greenest Home in America?” I don’t think so.
This is a subject about which we should all be humble.
Most of humanity doesn’t choose the absence of dwelling space, modern amenities and stuff; they live without all of that by dint of the fickle hand of fate. Their stalwart accommodation to their rude conditions makes our attempts to be green and sustainable laughable in comparison. You want green? How about a home built from the mud over there and the branches and leaves from the trees overhead? You want energy efficient? How about zero fossil fuels ever used for heating, cooling and cooking?
If we want to engage in a green contest, we’ll find it pretty difficult to compete with those who don’t need, don’t desire and don’t expect. Everythingthey build is LEED Platinum and Net-Zero. And we’re now coming to that game burdened with our considerable lifestyle-expectation deficits. We can’t win, but for the sake of all that is right, we must keep at it with dogged determination…and humility.