Net Zero Homes

A net zero energy home is one that produces as much usable energy on-site as it consumes. It may, at certain times of year - or even certain times of day - use energy from off-site sources, but to be truly net zero, it must produce at least an equivalent amount of surplus energy to match whatever it uses from sources off-site.

There is a lot of debate about what net zero energy building means and what it should be called. Some people focus strictly on energy use; some are more interested in emissions and carbon output. Some have suggested that to be truly net zero, one must include all the energy that has gone into the construction of the home and all of the embodied energy that went into manufacturing and transporting the materials to the site. Some have suggested that use of commuting and traveling fuels needed to maintain a lifestyle should also be included in the home's net energy or net carbon portfolio.

The point becomes very clear after going only a little way into this discussion. We can parse details in a debate, but net zero living is really about bringing one's own lifestyle and values into broad alignment with the sustainability capacity of the planet. It makes no sense, for example to build a net zero home in a location that will require you to commute long distances to work every day, or to use materials in the building that are extremely carbon-intensive in their production to avoid burning a small amount of fossil fuel in the building itself.

Net zero as a singular goal can also be achieved on almost any house simply by applying huge quantities of solar panels and thus maximizing the energy production of the site. But clearly, we miss the point if we don't make some significant effort at energy efficiency and resource conservation. Frugality, thrift, and lifestyle mindfulness are an important part of the mix. Appropriate low-tech solutions such as a clothesline can be as important and effective as the latest solar technology. Many people think net zero can be achieved by building their house right, fine tuning some smart devices, and going on with their lives as if nothing had happened.

But net zero won't work without us. It is not a device or a design so much as it's a habit and a mindset. It is as much about our own awareness and behavior as is about technology.

In a way, it is getting back to our New England roots. Vermonters traditionally have been thoughtful about their lifestyle - putting in a garden, putting food by for the winter, preparing their meat, keeping up their wood pile. They paid attention to the gifts that nature gave them. Their subsistence depended on it, and it had to be sustainable or else they wouldn't survive.

While not as rigorous as the subsistence lifestyle our great-grandparents may have been familiar with, net zero living also requires that we pay attention to the gifts that nature gives us in the form of energy - understanding the value of light and wind, natural evaporation, the heat in the ground - and tuning our habits so that we can take advantage of the gifts of the day.

Right up into the 20th century, many northern New England farms were almost 100% self-sustaining, and they were solar-based in their use of energy - from the orientation of the house, which took advantage of south facing slopes and natural wind-breaks, to the production and processing of home heating fuel - photosynthesis converting sunlight into the carbon-based growth of the tree, and the physical labor of the farmer (powered by solar-based proteins and carbohydrates) - converting the tree into stove-length logs that would heat his home.

Nowadays, net zero living is more about holding in the heat than it is about building up the fires; recognizing that nature gives us enough if we don't ask for too much, understanding that the earth is a finite system with infinite potential, if we are mindful of how we use it, and thoughtful about the way we live.