Going All the Way
by Michael Kracauer
As an architect, I am interested in creating beautiful, harmonious buildings. When I realized that architects were responsible for creating unsustainable buildings, I began to incorporate green features into my work. But the real turning point came when I saw “Solar Harvest” on the CRC tour, the first net-zero energy (NZE) house in Boulder. I realized that a sustainable future could be much closer than I had previously thought, and that as an architect I must help to give birth to this world of clean and inexhaustible energy. We decided to build our own NZE house with four primary goals:
1. Build an NZE house that achieves its goal without burning any fossil fuels.
The challenge of net-zero energy is to build a house that will produce renewably as much energy as it will use. But some NZE homes still burn gas for cooking and fireplaces. Others will even heat the home with gas and yet overproduce enough electricity to offset the carbon generated by the gas.
This NZE House will meet the NZE goal without offsets. It has a very well-insulated airtight envelope and high-performance windows, a 7.2 kW PV array for electrical needs, a 140 tube array of solar thermal evacuated tubes for space heating and domestic hot water, and is designed for maximum passive solar. There is a magnetic induction electric cooktop, and an EPA-certified woodburning fireplace. The backup for heating and hot water is achieved with efficient state-of-the-art electrical devices. For cooling we installed an innovative closed-loop earthtube. Because the house is so tight and well-insulated, cooling loads are minimal. This simple system should provide all the cooling we will need.
2. Show that an NZE house could also be architecturally distinctive.
All the features that make it NZE have been integrated into a richly complex, modern design. This is achieved without hiding the technology—the solar panels are proudly displayed and integrated into the most visible elevation. In addition, the passive solar south elevation overhangs are carefully designed into the modern composition of the house. And even though the envelope of the house functions like a thermos, there is a generous amount of glass to bring in light and views.
3. Build a “not so big” house.
Some high-performance houses are so huge they almost erase their benefits because of their vast embodied energy, and they still may require lots of energy to run. The NZE House is modestly sized at about 3000 sq. ft., which includes 300 sq. ft. for the Architropic office.
4. Make transportation to and from the house more sustainable.
We achieve this goal in two ways. One is to place the house in town and close to public transportation. This proximity allows our kids to use public transportation instead of being chauffeured by their parents.
Second is to have the house produce enough excess renewable energy to power plug-in hybrid electric vehicles (PHEV’s). We will have enough excess power for one and possibly two PHEV’s. We are very excited that Hybrids Plus agreed to bring a PHEV to the NZE House to demonstrate!
In the near future all houses will be NZE. The NZE House will help define the model for that future. |
