Now Is the Time for Zero Energy Homes

When Islip, New York architect James Bouler watched oil blackening a pristine shoreline in the wake of the Gulf Oil spill, he knew what his next project would be. Already a zealous proponent of net-zero energy buildings, Bouler created a video documenting a net-zero energy retrofit he designed. His goal: Give builders and architects concrete ideas to reduce energy use in their own projects.

Bouler took time from his busy schedule to answer our questions:

New York architect James Bouler explains how to build net-zero energy buildings

Q: A lot of people are skeptical that homes can be made more efficient without being very expensive. How do you respond?
A. I believe every house in America can be improved within the client's budget. You start by identifying the home's thermal weak points.

Q: Where are the thermal weak points in most homes?
A: Insulation, air sealing, and windows. You can realize big gains by using the proper insulation, using spray foam to block air filtration, and specifying high-performance windows.

Thermal weak points include insulation, air sealing, and windows

Q: What if the budget doesn't support high-performance windows?
A: Do the best you can. On the Hamptons zero-energy remodel, we wanted, but couldn't afford, triple paned windows, so we used a more affordable low-e window that blocked some of solar radiation. So far, the homeowner has been through two heating-cooling cycles and has hit zero energy both times. She receives an annual check from the power authority.

Q: We hear a lot about passive solar. How important is it?
A: Glazing should provide passive heating in winter and should be properly shaded in summer. With every project, we design overhangs on the south and west facades, which blocks the summer sun, but allows the winter sun in. In fact, when the zero-energy home was being remodeled in the middle of February, the house stayed at around 60° F without the heat on. That's because of the passive solar features we designed into the home.

One affordable way to get the most out of passive solar is to use a poured concrete floor as a thermal mass to hold the sun's heat. Another is to install clerestory windows (windows that are above eye level) that can open to vent hot summer air.

Install quality windows to keep your home insulated in winter and cool in summer

Q: What do you recommend for heating?
A: The best thing is a high-efficiency HVAC system. Condensing boilers and geothermal are great if the budget permits. For example, the remodeled home in the video has a geothermal system powered by a photovoltaic (PV) system, which uses solar cells to convert light into electricity.

Q. What do you think is the biggest impediment to making homes more energy efficient?
A. Aesthetics. The Hamptons zero-energy remodel got the highest rating from ENERGY STAR® on Long Island but also had beautifully shaped PV panels. I broke the roof into three elements -- two towers and one curved roof to soften the structure. A PV system is integrated into the roof.

Q. How does a builder get started?
A. Deal with thermal performance first, then determine if solar is a good application. For some projects, solar will too expensive, or the site could have too many trees that block the light.

Install a high-efficiency HVAC system to heat your home

Look for easy solutions. For example, consider a VELUX® solar thermal skylight to heat water. A skylight doesn't require a large amount of roof, and it doesn't have to face solar south. If you can't afford to take off the siding to insulate an old house, take a piece of siding off the top and one off the bottom and spray in insulation — fill it from the outside.

Any energy-efficiency improvement is going to make good financial sense. Natural gas, oil, and electricity will only get more expensive, so it makes sense to address the energy efficiency of homes now.

Image courtesy of Velux® Solutions