Re-siding your home? Participate in a Study!
PNNL has been funded by the U.S. Department of Energy to conduct
Air leaks and poor insulation are common in homes built before 1992—about 68 percent of existing residential buildings lack adequate air sealing and insulation. Poorly insulated walls in residential buildings waste an estimated quadrillion+ Btus per year of energy. Installing R-5 exterior continuous insulation at siding replacement could save more than 25 percent of that total and is considered a top-10 energy upgrade for retrofit investment. Unfortunately, the best solution for this energy and comfort issue requires disturbing exterior siding and trim. Since removing siding can be costly and disruptive for homeowners, there is a unique and underutilized opportunity to perform these energy upgrades during home re-siding projects.
More than one million homeowners replaced approximately 4 billion square feet of exterior siding in 2020. Yet less than 10 percent of these projects capitalized on the opportunity to add 1 inch or more of insulation. Occupants in these homes may be unaware of the improvement opportunities a re-siding project presents.
These energy upgrades may provide:
Illustrations by Michael Perkins | Pacific Northwest National Laboratory
A re-siding project presents the perfect opportunity to upgrade the windows, too.
Viable window upgrades depend on the condition of the current windows. During the initial stages of re-siding projects, windows may be in worse condition than the homeowner expected. As with adding air sealing and insulation upgrades, the perfect time to upgrade windows is during a re-siding project.
If the home's current windows are in poor condition, replacement is a much simpler process during re-siding than at any other time. Modern double or triple pane offerings from all major manufacturers offer exceptional energy performance that will contribute to lower energy bills and greater comfort. Reduce heat transfer and prevent summer overheating by choosing ENERGY STAR performance values indicated in the map image at right. For tips on finding and installing ENERGY STAR windows, see:
What makes it ENERGY STAR? and Buying and Installing the Right Product.
Window replacement is not the only option, however. If the home’s current windows are in good working order, an exterior storm window with low-e coating (installation example shown on the right) is a cost-effective energy upgrade. These windows can still provide opening options and offer improved thermal comfort and better sound control compared to older windows, at a fraction of the cost of new energy efficient windows.
Low-e storm windows are around $100 to $200 per window and capture a large portion of available energy savings, while new high-efficiency triple pane windows can be over a thousand dollars each, with professional installation. Modern low-e storm windows are attractive and easy for DIY installation.
Inclusion in this section does not indicate PNNL endorsement of a company or practice and is solely for the purpose of information.