Net-Zero Energy Homes for the Masses

If you were to rank sustainable homes primarily based on their energy efficiency, ZNE homes would rank extremely high. They’re pretty cool. And complicated. In a recent blog about ZNE homes, I explained the complexities of designing these homes — not only do they need to be incredibly energy efficient, but must also be designed to create as much (and hopefully more) energy than it uses, hence establishing a zero net energy use from the grid.

Net-zero homes achieve their energy efficiency by working from the very start with this goal in mind. There are two sides to this equation — the home design must be as energy-efficient as possible so they require less energy, and then it must maximize the use of on-site energy sources such as solar, wind, and geothermal so they produce enough energy to power the home on their own, achieving a net zero in-take of grid energy.

All “off-grid” homes are net zero, but net zero encompasses a larger category, since zero energy homes are typically attached to the energy grid. There may be times that a net-zero home pulls more energy from the grid than it is producing, although it will make the difference up during periods of lower energy use.

Testing the Prototype Net-Zero Energy Home

PulteGroup selected California to build and monitor this home prototype and for very good reasons. According to a comparison completed by Wallethub, California ranks in the top 10 states of the most costly energy bills. And according to Mr. Jamison, California also hosts some of the most eco-conscious consumers. Both of these factors make building the prototype in California a logical location selection, before branching into other regions.

During construction of the prototype home, Pulte has learned a lot about materials and techniques for energy efficiency. For example, “We are learning quite a bit about the methods and products for insulation.

Cathederalizing the attic insulation is a tool in which you place the insulation up near the roof rather than the floor of the attic. Cathedralizing turns the attic space into a partially conditioned space. Your attic is much, much cooler or warmer, which is closer to the indoor living temperatures and the energy efficiency of the duct work in that space increases too since it is not exposed to the extreme temperatures some attics experience.

Also, an airtight home (sealed very tight) creates a need to provide indoor fresh air as well as exhausting the air. This becomes very important to design as a house has to breathe — if a house doesn’t breathe it will struggle.”

Using a high-efficiency solar system will greatly reduce the need for an abundancy of solar panels. The Pulte home prototype is expected to earn all of its energy needs through a high efficiency set of 4?kilowatt 14 panels system.

Once the house in completely built a family will live in the prototype home for 12 months while the home is monitored for its energy performance and consumption and overall functionality. Some ways in which this monitoring will occur is by including twice as many circuit breakers as a typical home, viewing the energy use at a “myopic level.”

Mass Distribution of Zero-Energy Homes

As one of the top three home builders in the USA, PulteGroup’s success of this prototype creates the potential for mass distribution of zero energy homes and can have a significant and positive impact for the sustainable home movement.

But this excitement doesn’t come without some hurdles: cost and marketing to the masses.

Zero energy homes are often costlier and more difficult to build than a typical home of equal size given the level of modeling and expertise required upfront to design a custom home as well as the implementation of specific energy producing systems (solar, wind, geothermal, etc…) and building materials to match the climate and regional needs.

Not unlike the Sears Modern Home designs which had the ability to use mass production as a means to lower manufacturing costs and passed on those savings to the homeowners, mass production of zero net energy homes could very well do the same.

Marketing to the masses will also be essential to convey to new home buyers the environmental benefits and energy savings that can offset higher up-front costs. With the help of companies such as VivaGreenHomes, one of the largest databases of eco-friendly home listings nationwide, hopefully marketing eco homes to the mass consumer will also become mainstream. Fingers crossed.

So from your modern day Sears, Roebuck & Co. catalogs (a.k.a websites), sit back, pick out your Tesla electric vehicle from their website and select your next eco-friendly home from VivaGreenHomes, featuring zero net energy homes listings among thousands of other eco-friendly homes for sale across the country. If PulteGroup is successful with their next line of ZNEs, you’ll have even more green home options to choose from for your next purchase. Read more about PulteGroup’s zero net energy home project.

Photos by PulteGroup

Kari Klaus is a Northern Virginia Realtor and founder and CEO of Viva Green Homes. In addition to working on establishing Viva Green Homes as the most popular sustainable homes site, she also is volunteering and working with local animal rescue groups in Mexico. Read all of Kari’s MOTHER EARTH NEWS posts here.

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