As materials and equipment have improved, energy reduction as a goal has increasingly been replaced with the goal of net-zero energy use. But the general approach to building energy efficient homes that has been recommended has always been the same. This approach to achieving net-zero energy homes is reflected in the ten general principles for the design of net-zero energy capable houses that are presented and discussed in the first part of this paper. In the second part of the paper, specific strategies and details are described that were used for the design of the Net Zero Energy Residential Test Facility (NZERTF), a NIST laboratory in the form of a typical residence for a family of four that has been constructed on the NIST campus in Gaithersburg, MD. Read more...

So what does “net zero” mean anyway? And what is the difference from a “zero energy house”? A zero energy house is “off grid” and makes all the energy it needs on site using renewables. This is not easy to do and typically involves an ultra efficient house and energy storage. Good luck. Having said that, I like the ultra efficient part. I can’t help it. Engineers worship efficiency. The storage part worries me. Read more...