Transition Towns write Energy Descent Action Plans to guide their communities toward a sustainable and prosperous way of living in a world with less and less cheap energy. We hope this pyramid can be a tool for the Carrboro-Chapel Hill energy descent.

This is energy efficiency from the bottom up! You can start at the bottom of the pyramid with actions like information-gathering that cost nothing, then move gradually up the pyramid from super-low-cost energy-saving measures to ultra-sophisticated (and costly) ones. Click on each level for details, and check back often for updates.

The above pyramid deals with retrofits to existing buildings. Below is an article by green architect Giles Blunden pointing out things that need to be considered when designing and constructing a new building.

New Construction Design

Designing a new home for energy efficiency

The energy required to keep your home comfortable in Orange County is almost equally divided between heating and cooling. Heat pumps have become a popular HVAC system. In the winter they pump heat extracted from the outside air into the house and in the summer they pump heat from the air inside of the house out. In designing a new home here, equal consideration should be given to each season. If you assume that the internal loads from people and their activities are roughly the same year-round, then you need to design the home to manage the external loads.

There are two elements at play here: keeping the heat in in the winter and out in the summer. Some of this can be accomplished by air tightness and insulation, discussed in other parts of this site. Another often overlooked heating and cooling strategy is managing the heat from the sun, keeping it out in the summer and letting it in during the winter. This is known as passive design. In the winter, the sun is low in the southern sky, so allowing for more windows on the south wall brings in free heat in the winter. In the summer, we want to do just the opposite: keep the sun’s heat out so we don’t have to pump it out with the heat pump. The summer sun is much higher in the sky, so with some careful shading of the south windows (with an overhang or awning, for example), we can keep the midday sun out in the summer, but allow it in during the winter, when the sun is low enough in the southern sky that the overhang does not block it from entering the windows. In the summer, shading the east and west windows is important to keep the sun’s heat out. Porches do a great job of this and leaving large shade trees on these sides can help a lot. Skylights are one of the worst offenders when it comes to keeping out the summer sun’s heat. One good solution for letting in light from the sun without the heat is the Solar Tube. Designing your home with porches on the east, west, or north is also a way to enjoy the wonderful weather we have in the spring and fall. A screened porch allows you to open your whole house up during these seasons. In Orange County we are lucky to have one of North Carolina’s best passive solar architects, Alicia Ravetto, and a nationally recognized green designer-builder, Michael Chandler and his team.