Net-Zero Energy: How To

Net-zero energy homes are no longer anomalies. New technologies and better building practices have tightened up building envelopes to the point that, with the addition of renewables such as PV and geothermal, homeowners pay nothing to heat and cool their homes—and sometimes even get a check back from the utility company for selling power back to the grid.



Architect James Bouler of Bouler Architects in Islip, N.Y., is a zealous proponent of net-zero energy buildings. His first-hand experience watching oil wash up on a pristine shoreline in the wake of the Gulf Oil spill prompted him to create a video of a net-zero energy retrofit to help Americans reduce their dependence on fossil fuel. Watch the video for more information on net-zero energy practices: 

While there are many videos you can watch on the topic of net-zero energy houses, this one is particularly important because it shows some of the more simple ideas that builders should consider when siting a house, choosing materials, and using renewables.

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Here’s some additional points Bouler shares for those interested in learning how to get their houses as carbon neutral as possible:

Q. Reducing our dependence on oil is what has motivated you to educate the public about net-zero energy houses. Tell us more.
A: Nature and the environment are finite. When the Gulf oil spill happened … when you could look across a body of water as large as the Gulf and think it’s possible that we as people could mess it up, it’s just inconceivable and devastating. The dispersants used as part of the cleanup dissolved part of the oil and caused the rest of it to form into rock, which is now at the bottom of the sea and part of our ecosystem—our food chain.

Using renewable energy makes sense because it’s apparent that gathering oil is a dangerous proposition. Easy oil is gone. Now we are drilling in a mile of water with little safeguards and regulations—and there are 25,000 active wells in the Gulf that are capped.

Q. So you believe builders hold a key here with their ability to reduce the energy footprint of homes. But do you believe the houses builders put up today can be made more energy efficient without being too expensive?
The energy efficiency of every project can be improved. Some can go as far as zero energy. I try to determine how much energy efficiency we can instill using architecture within the client’s budget. The most important thing to do is proper insulation. You can block air filtration by using spray foam insulation; then spec new high-performance windows.

Perhaps the best thing is a high-efficiency HVAC system; condensing boilers and geothermal are great. For example, the remodeled home I illustrate on the video has a geothermal system power by a PV system.

With every project, we design overhangs on the south and west faces. This allows in the winter sun but blocks the summer sun. (See the video for a diagram.) Builders need to remember that glazing is not a bad thing if designed to provide passive heating.

Another idea is to use a poured concrete floor as a sink; you get a thermal mass that holds the heat from the sun. Combined with a geothermal system and clerestory windows that can open to vent hot air and pull cool air through the home, you can reduce your electrical or natural gas demand.

On this particular project, we couldn’t afford triple paned windows [which allow solar gain in the winter]. We used more affordable low-e windows to block some of solar radiation. So far, the homeowner has been through two [heating-cooling] cycles and she hit zero energy both times. She gets a check from power authority.

Q. What are the key points you think builders overlook?
One thing is aesthetics. The trick on the Hamptons remodel (which has the highest rating from Energy Star on Long Island) was to get a beautiful shape for PV panels. I like the roof and solar to be in one plane. The challenge was that the south-facing windows and roofline encompassed the water views. The roof has to face south so what would have been the perfect shape from solar perspetive is a wedge. And that would look horrible. So I broke the roof into three elements—two towers and one curved roof to soften the structure. A PV system is integrated into roof.

Just as important is passive solar. When the home was being built in the middle of February with no heat on, the house stayed at around 60 F. That’s because of the passive solar features.

Q. How does a builder get started?
Find the part of the building that is the most inefficient—it could be heating or windows or insulation. I would deal with thermal performance first, and then determine if solar is a good application. For some projects, solar is too expensive, or the house is on a site with too many trees. Look for easy solutions. For example, consider a VELUX solar thermal skylight to heat hot water. It doesn’t require a large amount of roof and it doesn’t have to face solar south.

I believe every house in America can be improved. Just go through the steps of addressing the budget and identifying the weak points. Obviously, insulation is one of the biggest culprits in terms of losing energy.

In an old house, for example, if you can’t afford to take off the siding to insulate—take a piece of siding off the top and one off the bottom and spray in insulation—fill it all from the outside. The payback is that all energy-efficiency improvements make good financial sense: Natural and oil and electricity will get more expensive. Heating oil this year or next could be up to $5 a gallon. It will be a hardship for Americans, so it makes sense to address the energy efficiency of homes now.


Do Your Part

Save the Gulls

Bouler is the father of Olivia, whom you may know as the 11-year-old budding ornithologist and artist who single-handedly raised more than $175,000 for the Gulf oil spill recovery. Devastated by the disaster and eager to do her part, Olivia wrote a letter to Audubon offering her own bird paintings to raise contributions for Gulf recovery efforts. The idea took flight, and Olivia sent out over 500 paintings, many of which are captured in this lavish picture book that recaps her valiant campaign to save birds affected by the spill.  Buy a copy of Olivia's Birds and help support the ongoing effort to right the wrong done to the environment in the Gulf