Introduction to zero energy homes

Building a zero energy homes isn't a big deal if you have a million dollars,building one at an affordable cost is the challenge. What is a zero energy home? A zero energy home is on that is capable of producing all of the energy it needs, for heating, cooling, lighting, hot water, and all of the other appliances we have in our homes. The key to building this in a cost effective way starts with efficiency, reducing the homes energy needs is the first step. How many ways are there to reduce energy usage? How many ways do we use it? Make a list of all of the energy we use in our homes and then come up with ways to reduce each one, starting with the largest users, like heating and cooling. These two typically use more energy over the course of a year than all of the other energy consumers in your home combined. Building an air tight, super insulated envelope is the first step in the process but just the beginning. Along with an air tight house, you need to consider passive solar energy and how it relates to your home. Here in MA we use the sun as a way to help heat your home and then shade it during the summer to reduce cooling loads. If you live in the deep south you would want to shade you windows almost all of the time and even limit the amount facing the southern exposure. I am of course talking about the US but if you live in the southern hemisphere this would be north instead of south. Simple steps during the design process are key to using passive solar energy wisely. Proper orientation to utilize the available energy to it's full advantage. Proper siting to ensure that trees do not block out the suns energy in the winter, but also located to block it during the summer, not always an easy task. I will continue to post about this subject as we continue to build more homes heading in this direction, always searching for ways to build better buildings that use less energy. Renewable energy is the easy part, anyone can put solar panels on their roof and start producing energy today. But if your home isn't energy efficient first you will be throwing away that energy and your money as well. Some solar guys hate me, I tell it like it is. If you install solar panels without first finding ways to reduce your energy needs you are putting you money in the wrong place. Energy efficiency improvements always have a greater payback than renewable energy systems and should always be the first step for any home considering solar energy systems.
Building a zero energy homes in a cost effective way consists of integrating four key elements, design, methods, materials and systems. By integrating these four elements I can today build a 2,000 sq/ft zero energy home for around $330,000. Not exactly affordable but not out of the reach of most Americans. Many have payed a lot more for a home that consumes thousands if not tens of thousands of dollars in energy costs yearly and produces tons of carbon emissions in the process. Stay tuned more to come in the near future.

Tom Pittsley
ecobuilder@aol.com
www.eebt.org