The concept of passive home construction has been around for a while; however, it has increased in popularity in recent years with the growing interest energy efficiency.
Whereas net-zero home construction is about offsetting a home's energy requirements with solar panels and other energy renewal solutions, passive home construction focuses on reducing a home's energy and ecological footprint. How is that accomplished?
--By constructing a home that is airtight but also ensuring good air circulation and quality.
--By installing super-insulated walls, ceilings, attics and basement spaces to keep the home warm during the winter months and cool in the summer.
--By using high thermal mass elements to act as reservoirs for storing heat and energy in the home when outside temperatures drop.
--By strategically locating windows and window shading to help regulate a home's interior living space.
--By building the home on the lot to maximize sunlight for active living during the various parts of the day.
--By overall minimizing the home's dependency on traditional heating, ventilation and air conditioning systems.
--By constructing the home so that it is primarily heated by passive solar gain.
Detailed construction practices for passive home construction include the use of multilayer mudsills, a super-insulated slab, double-stud wall framing, spray foam insulation and high-insulation R-value doors and windows. Standard home building material can be used to construct a passive home. However, you need more of it and higher-quality products, e.g., doors and windows, which adds up in terms of cost. Also, the best type of house plan for building a passive home is the simple cube-shaped house.
For certification purposes, after a passive home has been buttoned up, multiple blower door tests are done to ensure that the home is effectively airtight.
Passive home certification is based on three major components:
1) Air infiltration (? 0.6 ACH).
2) BTU consumption (? 4,755 BTU per square foot annually).
3) Kilowatt-hour usage (? 11.1 kwh per square foot).
To conclude, passive home construction is all about energy conversation and capturing as much of the cheapest energy possible (solar) and holding on to it to minimize the home's ecological impact. Make no mistake; there is a huge financial investment required to construct a certified passive home. As such, there are only about 75 homes in the U.S. that are certified at the time of this writing. That said, even if you elect not to build a certifiable passive home, there are a lot of things to be learned by studying passive home construction to ensure you build your own energy-efficient home.
Mark J. Donovan's website is at http://www.homeadditionplus.com.