Greenbelt Homes, Inc. Releases Case Study
It seems to always become a topic in the Northern Virginia Real Estate Market due to the nature of our older housing stock. We have homes built back into the seventeen and eighteen hundreds, and insulation wasn’t their biggest concern at that point in time, let alone the plumbing! Now, how about we jump ahead into the 1920-1950 range, when homes were built “strong” and to endure, yet, they weren’t necessarily built to be insulated and with products that were meant for healthy indoor air quality.
A group out of Greenbelt, Maryland has over that last three years has worked in conjunction with the United States Department of Energy, or US DOE, to create a pilot program to monitor retrofitted homes in the mixed-humid climate zone. These homes were built in the 1940-1950 era out of concrete, and vinyl- products that are quite typical of the climate zone we live in and of the standard building practices of the 40’s and 50’s in our general area. The homes had standard construction practices of the new era of code and energy efficiency standards implemented for energy and efficiency retrofitting.
The US DOE described the project in an executive summary:
The pilot project has three phases focused on identifying the added costs and energy savings benefits of improvements planned for implementation during a planned community-wide retrofit program commencing in 2015. Phase 1 provided a baseline evaluation of the current operation, use, environmental conditions, and energy costs for a representative set of 28 townhomes sited in seven buildings. Phase 2 included the installation of the building envelope improvements identified in Phase 1, continued monitoring of the energy consumption for the heating season for comparative evaluation of the performance before and after the improvements, and energy simulations supporting recommendations for heating, ventilating, and air conditioning and water heating upgrades to be implemented in Phase 3….
When looking at the overall cost of the upgrades implemented during the pilot program and evaluating these costs solely on the basis of energy savings, the simple paybacks are long—29– 70 years. However, with the costs of the upgrades, including new crawlspace vapor barriers, windows, and siding (which are replaced on a regular schedule and financed separately), the payback periods are reduced by 11–34 years. Based on the type of upgrades—and given the more than 30-year periods between major improvements—payback periods of 30 years or longer are acceptable.
The analysis of the measured data also highlights the complexity of comparative evaluation of the energy use (energy savings) before and after the home retrofits, especially because the occupants’ preferences for thermostat setting levels changed after the retrofit. The high energy costs prior to the retrofit may have led to lower thermostat settings during the winter in an effort to conserve energy; however, envelope improvements helped lower heating energy consumption, which led to a higher thermostat setting for improved comfort. This was the case in most of the GHI pilot homes. During the latest winter season after the upgrades, the highest average indoor temperatures were recorded even though the average outdoor temperature was lower than in any of the previous three monitored winter periods.
Check out the full report
The full report is available for review here and I encourage you to take a look. I truly believe in retrofitting the aging housing stock- not just in our area, but across the nation, for a higher impact on your pocket book for return on your investment if you are purchasing or investing on updates to an existing home in Northern Virginia or within our mixed-humid climate zone.
