Passive House Technology Underlies Going ‘Net Zero Energy’

“Passive House” is a concept born in Germany as “PassivHaus” but growing in popularity here in America. Although its primary focus is on reducing the heating and cooling needs of a home through proper north/south orientation, the placement of windows, and roof overhangs, it also includes design elements that make a home better for its inhabitants. It has many other positive impacts as well, including healthier and quieter spaces, greater durability, and greater comfort for inhabitants.”

Prior to the oil embargo of 1973, home builders did not concern themselves much with making homes energy efficient, but that all changed as we quickly realized how dependent we were on foreign countries for fossil fuels to heat our homes and fuel our cars. Homes built before then were poorly insulated, drafty and less healthy.  (For example, lead-based paint wasn’t banned until 1978.)

The passive house concept took off in America as a result of that wake-up call. The “Lo-Cal” house created in 1976 consumed 60% less energy than the standard house at the time, and the concept continues to mature.

If you participated in any of the “green home” tours that Golden Real Estate co-sponsors each fall, you’ve learned about various passive home strategies in addition to “active” strategies such as solar power, heat pumps, geothermal heating, and energy recovery ventilators.

When “active” systems are introduced to a home with passive house design, they work more easily to create the ultimate goal of a “net zero energy” home — one which generates all the energy needed to heat, cool and power the home and, perhaps, charge the owner’s electric vehicles.  Without passive house design features, you can still achieve net zero energy, but it may require substantially more solar panels to compensate for such factors as inferior orientation, fenestration (windows) and insulation.

You can learn all about passive home technology, including trainings and public events, online at www.phius.org. Also, search “Passive House SW” at www.meetup.org for local events.

An excellent example of new construction which combines passive house design with smart active systems in the Geos Community in Arvada, which you can learn about online at www.DiscoverGeos.com. The homes in Geos are all oriented to maximize solar gain in the winter, but also designed for sun shading in the summer. Some have a geothermal heating, while others have air source heat pumps and conditioning energy recovery ventilators (CERVs). The CERVs installed in the Geos homes not only provide heat when needed but also track the level of CO2 and volatile organic compounds (VOCs) in the air and adjust their function to reduce those levels, thereby improving indoor air quality.

None of the Geos homes uses natural gas, just solar-generated electricity.

My Advice on Buying Solar Panels and Electric Cars

By JIM SMITH

In the wake of last Saturday’s green homes tour and electric vehicle showcase, I’d like to share the advice I give to people who ask me about investing in solar power and buying an electric car.

As much as I wish it weren’t so, you will not recoup what you spend on solar panels, insulation and other green home improvements for your home when you sell it. As with any improvement, you will receive a percentage of what you spend, but it will not be anywhere near 100%. Only make those investments because you’ll enjoy the comfort and savings for at least a few years — and because it’s the right thing to do.

Regarding electric cars, I recommend buying a used EV. The used car industry has yet to properly value used EVs. Currently electric cars are devalued the same way gas cars are devalued, which doesn’t make sense. Consider a 4-year-old gas-powered car with 100,000 miles on it. You can probably get it for half its original price, because so many components, such as transmission, timing belt or fuel pump, are worn and might fail. But none of those components exist in EVs. There are under 50 moving parts in a Tesla. The same age EV is simply as good as new.

A used Tesla built before mid-2017 is an especially good deal, because lifetime free supercharging transfers to the buyer (unless purchased from Tesla). I’ve seen many Tesla Model S cars for sale online under $40,000, less than half their original price. Here’s one I found just now on autotrader.com….