Toward a Zero Energy Home
Download Chapter 1 - The Building Envelope for free. Read it and pass it on.
A Zero Energy Home (ZEH) -- a home that produces as much energy as it consumes -- is an idea whose time has come! Authors David Johnston and Scott Gibson (Green from the Ground Up) explore the design and construction of self-sufficient houses from start to finish.
Read more about Zero Energy Home or purchase the book.
The world of zero energy homes is all about rethinking the envelope, or outer layer, of the building, which includes the roof, walls, and foundation. The challenge is to build an envelope that is airtight and well insulated as possible so that the energy that comes into the building stays within the envelope, and any inclement weather outside has little impact on the comfort inside.
Not too long ago, a house that used 60% less energy than one built to code was called a near zero house. That was quite an accomplishment. A house that was this energy efficient could be constructed mostly with conventional materials and techniques but with more attention to details, such as air sealing and insulation. Today, homeowners, builders, architects and remodelers are exploring new approaches to the task of building net zero and near net zero homes; homes that take the goals of sustainable building one step further by producing as much energy as it uses on an annual basis.
Building Houses a New Way
By minimizing utility bills or even creating the potential for the home to make money by selling energy to the utility at some point in the future, zero energy homes offer a new direction for housing in America. It is a win for the homeowner, for the planet in aggregate, and for a new generation of builders who will be able to construct houses that better meet future energy challenges.
At greenbuilding.com, we spoke with builders, architects, remodeling contractors and homeowners about their efforts towards energy self-sufficiency. Some got closer than others. We have created a snapshot of some of the projects, to give you an idea of the unique challenges and unexpected solutions developed during the building process:
- Zero Home Case Study Brainbridge, Seattle
- Zero Energy Home, Boulder, Colorado
- Green Building in Ferrier, Texas
Achieving the goal isn't as much the focus as the journey to building a zero energy home. We asked them questions, like
- how they met their goal
- how much it cost
- what were their options
- what lessons did they learn along the way
Building a net zero house is about reducing the amount of energy needed to heat and cool the house. This means different things to different members of the project. For the builder it means building a tight, well-insulated building envelope; for homeowners it may mean more awareness about their energy use.
There is no single path toward energy self-sufficiency, nor are we arguing that building net zero houses will magically solve the world's energy or climate problems. Many of the builders, with whom we spoke, talked about the 80/20 rule; 80% of the load reduction can cost only 20% more than a standard house, but that last 20% can mean an additional 80% of the incremental cost. This is hardly a failure. What if all new houses in the United States used 90% less energy than what we use now? Even 80% less? The impact would be immense.
Interested in reading more interviews? They are collected in a book written by David Johnston & Scott Gibson called "Toward a Zero Energy Home". or Download Chapter 1 - The Building Envelope for free. Read it and pass it on.