Texas is one of eight states funded by DOE to conduct a Field Study to determine if energy efficiency in single family homes can be measurably improved through an intensive education and outreach effort. SPEER, the National Association of State Energy Officials and the State Energy Conservation Office are collaborating in this work. A portion of Texas has been designated as the study area for data collection.
Energy efficiency building practices are important everywhere, but it is especially important for Texas to have an effective code education and compliance effort because of the enormous number of homes built here each year. Five of the 15 cities with the largest numeric population growth in the country are in Texas, including Houston (#2), San Antonio (#4), Fort Worth (#6), Dallas (#7) and Austin (#8). The number of new homes built in Texas each year far outnumbers that of any other state.
Construction practices vary significantly and there is a shortage of empirical data on how industry standards are applied in the field. The DOE Building Technologies Office’s Building Energy Codes Program (BECP) has supported research teams that gather baseline construction practices and trends across states, helping states and others with a vested interest in energy efficiency and consumer savings better understand the opportunities, challenges, and savings that can result from the building energy codes they’ve already enacted.
Texas Field Study:
Beginning in 2014, SPEER implemented a Field Study to assess baseline energy efficiency in new single-family residential buildings and quantify the related savings potential. The original methodology was developed by Pacific Northwest National Laboratory (PNNL) to target areas of improvement through energy codes and broader energy-efficiency programs.
PNNL identified individual key energy-efficiency measures with the largest direct energy impacts: envelope air tightness, window solar heat gain coefficient (SHGC) and U-factor; wall insulation; ceiling insulation; lighting; foundation insulation; and duct leakage. Since the initial pilots were commissioned, several additional states followed in funding similar studies of their own based on the DOE methodology – over 20 states have used the approach to date.
Using the methodology, SPEER has been able to gather insight on trends surrounding key technologies and efficiency measures as observed in real homes. Results are statistically valid at the statewide level and are based on a single site visit to ensure confidentiality.
Phase I data collection and analysis is complete. For analysis and savings potential, visit our Phase I Results page. Phase II training and outreach is in progress. For more information on SPEER’s training efforts, visit our Training & Resources page. Phase III data collection is in progress and will be completed in July 2018.
The Phase I findings indicate that some key measures are met more successfully than others. For example, the vast majority of window u-factor observations across states met or exceeded state code requirements, a trend that was observed across all states and climates studied. Similarly, cavity wall insulation almost always exactly met the prescriptive (R-value) requirement, although there was generally room for improvement in terms of installed quality. Envelope airtightness was commonly observed in the range of 5 to 7 air changes per hour (ACH50), even in states with no explicit testing requirement. Lighting observations were much less consistent, commonly ranging as widely as 0 to 100% high efficacy. With more data, a better understanding of these trends and patterns can be gained – which will help further capture typical construction practice and associated savings opportunities.