August 5th, 2019
Deep Energy Retrofits Critical to Aging Houses
Potential homebuyers are finding themselves priced out of the new home market before they even get started, leaving them to choose between continuing to rent or purchasing from the inventory of aging home stock in the U.S. According to a recent report compiled by the U.S. Department of Energy (DOE), Pacific Northwest National Laboratory, Oak Ridge National Laboratory and the University of Minnesota, 70% of current housing, or 92 million homes, were built before 1990—before stricter building codes were in place.
What Does That Mean for Us?
Since 2010, the remodeling market has expanded by 50%, and systems upgrades—including replacement windows—have made up 50% of those upgrades. Further, we know from the report that 39% of total energy is consumed by the building sector, and that 20% of that can be attributed to residential homes with little to no air sealing, resulting in heating and cooling losses and higher energy bills.
Today, as HVAC and window and wall technologies have advanced, the need for deep energy retrofits (DERs) has become apparent. DERs are defined as mechanical and envelope upgrades that achieve energy savings by as much as 30–50%—significantly higher than many state-level weatherization programs, which average around 23% on an annual basis.
In some cases, achieving DER levels of savings can be challenging based on climate, home configurations and more. In fact, an estimated 34.5 million homes have wood studs and no insulation, and 71% of existing homes have air leakage rates of 10 or more air changes per hour at 50 pascals of pressure, which is pretty extreme.
What Can We Do?
Based on data from the report cited earlier, DERs are necessary in much of the viable housing stock in the U.S. to reduce energy bills and energy loss in residential buildings overall, meaning we have an opportunity to use technological advances to help solve this problem for homebuyers and owners.
In my last blog, I covered the topic of Skinny Triples (triple-pane glass with a thin inner lite of glass) and their potential role in achieving greater efficiencies in new home construction, especially in California where higher levels of efficiency are being mandated. But I also believe there is a side benefit of Skinny Triples in that they can help achieve the efficiencies needed for DERs.
To recap: Skinny Triples use a very thin glass for the center lite and krypton gas filling in a triple pane insulating glass unit (IGU), which has been made possible at a reasonable cost because of the volume of thin glass being produced for flat panel TVs and the much lower cost of krypton gas. In terms of cost savings, the California Energy Commission compared the cost of alternative building envelope improvements and came up with a potential savings between $5.50 and $6.60 per square foot of window area. They are also more economical for manufacturers to produce compared to traditional triple-pane IGUs, because they require fewer design changes.
The View from Here
Purchasing homes with retrofit potential is often the only choice for first-time homebuyers, which presents an important opportunity for the fenestration industry to provide highly efficient options that can achieve DER levels of performance.
The View from Here is that the aging housing stock combined with increasingly strict codes at state and local levels will continue to draw more attention to the impacts and economics of windows on the building envelope compared to other insulating options, meaning continued growth for R&R and highly efficient window products.
Read the full report referenced in this article: Wall Upgrades for Residential Deep Energy Retrofits: A Literature Review, June 2019.
What’s your View? Email me directly at firstname.lastname@example.org.