Our latest zero energy home project is underway in Newcastle. The home is being built for Nick and Sandra Barth. It is a 1900 square foot single story home with an attached two car garage.
What separates this homes from others in the neighborhood is that the Barth’s will never have energy bills. The house will be super insulated and air sealed. The Intus windows, made in Europe, are very efficient, With most of the windows on the south side much of the heating will be passive free heat provided by the sun. A solar electric array will provide all the energy needed to power the home.
High performance green homes are beginning to catch on. More people are expressing interest in energy efficiency and solar electricity. When I began to research what it takes to build these high performance homes most people had no idea that a home could be built that would produce all the energy it needed with a roof mounted solar array. Of course back then most people could not afford solar. Today solar electricity has dropped in price to the point where it actually makes sense to install, making Zero Energy Homes affordable.
Our energy efficient green homes cost a bit more to build. The extra costs to super insulate, use better windows and doors, and install a solar electric array are soon recaptured with the elimination of energy bills. The pay back on the extra costs is somewhere between 5 and 7 years. The return on investment begins in the 1st month of occupancy.From an economic view I would say anyone not building a high tech energy efficient home is throwing away a lot money.
The Barth home will be built to the Department Of Energy Zero Energy Ready Home standard and then we will take it all the way to a zero energy home by installing a solar array sized to power the home. To qualify for the DOE rating the home needs to pass testing for air tightness and the levels of insulation need to be verified. The testing will be done by Wes Riley who is a certified HERS professional.
Building a high performance home requires paying attention to air sealing the structure. Air sealing begins at the framing stage of the project. We are using ZIP sheathing which is taped at all the seams. All penetrations from the basement up through walls to the roof need to be sealed with spray foam. Windows and exterior doors all need to be carefully sealed. This is done by using tape to seal on the outside and spray foam applied around the window and door frames.
The moment of truth comes when the home is finished and ready for testing. The process begins with a blower door test. The blower, which is connected to a computer, is placed in an exterior door. The fan will blow air out of the house creating a negative pressure. The computer will measure air flow and will determine air leakage. For the home to qualify for the Zero Energy Ready Home designation the leakage needs to be very low.
A bit more to building a Zero Energy Home but well worth the extra effort.
For information regarding the DOE’s Zero Energy Home program :
http://energy.gov/eere/buildings/doe-zero-energy-ready-home-resources