I was at a Passive House Northwest Board meeting when I heard that Passive House Institute US had been in talks with RESNET, home of the HERS energy ratings, to form a strategic partnership. The efforts of these two groups to jointly promote the reduction of energy use in buildings will benefit everyone and I wanted you to know all about it!
RESNET, the Residential Energy Network Services group formed in 1995, was a way that national energy ratings systems could be developed to aid the mortgage industry in understanding the energy use of buildings in an apples to apples manner. Additionally, many State, Local, and National opportunities for financial assistance are available to sustainable building efforts but depend on being able to judge the effectiveness of the method used in order to know if they should award the financial assistance to that builder or homeowner. Many of these opportunities rely on the HERS rating system to make those decisions.
If you wander through your favorite building supply store and look at the larger electrical or gas powered appliances like a water heater, washer, dryer, etc., you can see stickers on those appliances that show what the energy usage of that appliance is and also a way to compare it to similar models. If you have a relatively new water heater (within the last 10 years) it probably still has one of these stickers on it.
Now imagine that you could take an entire structure and apply some kind of rating to it and compare it to other structures. I live in a 1968 Rambler in the Pacific Northwest. My house was built with single pane windows. It now sports double pane windows. That change alone would have increased the energy efficiency some, but how would I know how much?
RESNET has established a rating system that can rate a home, taking into account whether it has single or double pane windows, is located in Seattle or St. Paul Minnesota, and after looking at several other factors such as insulation, construction, and orientation, give it a rating compared to a reference home that would have been built to the 2006 IECC energy codes. By comparing each home to the same standard you can look at how they operate compared to other HERS rated homes - that will be like comparing apples to apples.
So how does Passive House factor into this? By adopting the RESNET HERS index while still using the standards that Passive House demands of each Certified Passive House, that home can be awarded a HERS rating based on being a certified Passive House. This will open up opportunities for sustainable building incentives to Passive House builders and homeowners.
By expanding the importance of obtaining a Passive House certification to a system like RESNET that is already working with mortgage and other groups to promote sustainable construction, both groups will benefit. Passive House will reach a larger audience in a hurry, HERS will have a new method of sustainable building to promote that will fit in with its goals of reducing energy use in buildings.
Ultimately as more jurisdictions become familiar with Passive House, knowing that they are also associated with a ratings system those jurisdictions are already familiar with should encourage expansion into Passive House construction by firms and building departments that are not yet building to the Passive House standard. It’s Win/Win and that is always good.