Can you imagine living in upstate New York, where the average low temperature in January is 13 degrees, and only needing to use your heat once a year for 30 minutes? Dennis Wedlick LLC, an architect firm, has designed five houses in Columbia County that barely use heating or cooling systems.
The idea of passive houses, or “Passivhaus”, started in Germany in 1988, with the construction of four row houses that used 90% less heat than the average home. Today, there are over 25,000 structures in Europe built by this standard. The original idea was to design a home “which assures a comfortable climate in summer and winter without needing a conventional heating system”.
If you are looking into building a “green” home, or even just a custom house, it can be built as a passive house for practically the same price just based on the design. By using thermal model software, they can test and analyze for the environment and find the exact materials, window and door placement that will decrease the energy usage by 90% of that of regular buildings.
At his presentation for the Emerging Professionals Group of Urban Green Building Council, Mr. Wedlick explained that the greatest impact was the economic certainty of the buildings. Currently, one of their clients, Habitat for Humanity, is using a passive house design for one of their projects. It makes the most sense for the future inhabitants, that way they are never hit with an astronomical heating or cooling bill in January or July, that requires them to dip into their extremely limited disposable income.
Mr. Wedlick emphasized that these projects are not passive solar. He defined passive solar as being calibrated to collect, store and distribute solar, while the passive houses he creates are designed to minimize any type of energy use, saying you must put aside thoughts about alternative energy.
Passive house works based on its compact shape, thermal boudary, fenestration, airtight construction, conditioned air and fresh air systems. Through testing with thermal modeling software, they are able to fenestrate, or optimal place the windows where they will provide a net gain in heating/cooling the house. The thermal boundary works to stabilize the indoor temperature.
The most difficult challenge with the design is making it airtight, to fight drafts, while keeping the air fresh. Their answer to this is by using heat recovery ventilators.
The house they just finished in Columbia County is the 11th in the United States. Mr. Wedlick notes that currently this is still a very grassroots organization. While they do qualify for NYSERDA grant money, and Energy Star III, and LEED, it takes administrative talent and time to chase that money for the company. Right now, for the firm, the best case is to have a client already interested in a custom home, that is willing to try out a passive house design, since it costs about the same amount. Hopefully, we will start to see a lot more of these houses soon.