Results

Buildings account for about 40% of total energy use and 75% of electricity use in the U.S.— more than the industrial or transportation sectors (National Laboratory of the Rockies, 2026). This is likely to increase in coming years, as commercial data centers are rapidly growing to support AI computing and are projected to account for up to 12% of total U.S. electricity consumption by 2028 (Lawrence Berkeley National Laboratory, 2024). Reducing the energy use of our buildings has many benefits:

• Minimizing costs (and saving taxpayer dollars, for government buildings)
• Mission assurance, continuity of services, and facility flexibility and durability, e.g. through smart building technologies
• Improved reliability and longevity of the electric grid
• Promoting American energy independence
• Supporting innovative American-made technologies
• Cleaner air and water and healthier communities

GSA continually invests to maximize the energy efficiency of its buildings, which saves money both on monthly utility bills and by reducing the size and cost of equipment. Opportunities for increasing building efficiency include upgrading equipment and energy management systems, testing and tuning equipment and systems (commissioning), and applying modern high-performance building design practices. GSA’s High-Performance Building Clearinghouse provides many more strategies for improving energy efficiency in buildings.

Energy data results

FY 2023–2024 energy consumption data for each building in the analysis was converted to British Thermal Units (Btu), then expressed in terms of energy use intensity (EUI), or average consumption per gross square foot per year. Energy use intensity is typically measured in thousands of Btu, or kBtus, per gross square foot per year. The results indicate that GSA’s high-performance buildings are more energy efficient than both legacy stock buildings and commercial office building counterparts.

Specifically, over a two-year average:

• High-performance buildings’ EUI was 21% lower than GSA’s legacy stock buildings
• High-performance buildings’ EUI was 27% lower than the CBECS benchmark
• Legacy stock buildings’ EUI was 7% lower than the CBECS benchmark
• High-performance buildings used 12.8 kBtu less energy per gross square foot than legacy stock buildings
• High-performance buildings used 17.6 kBtu less energy per gross square foot than the CBECS Benchmark

The average EUI of GSA’s high-performance buildings is 47.85 kBtu/GSF, while the average EUI of GSA’s legacy stock buildings is 60.61 kBTU/GSF.

If an average-sized legacy stock building were as energy efficient as GSA’s high-performance buildings, one building alone would save 3.3 billion Btus annually. This is equivalent to the annual energy usage of 43 average American homes (U.S. Energy Information Administration, 2020), and could save taxpayers on average over $120,000 per building per year. If all of GSA’s legacy stock buildings in this study operated as efficiently as our high-performance buildings, energy savings alone would add up to over $21 million per year based on GSA’s national average energy costs.

The federal government collectively spent almost $700 million in FY24 on water and sewer services for buildings (U.S. Department of Energy, 2024). Implementing water conservation measures is a growing priority, due to increasing water demand and regional scarcity, and rising costs of water.

Building-related water efficiency efforts seek to reduce water consumption and related expenses without sacrificing water quality, occupant needs, or building performance. Building water use includes both indoor water use, such as plumbing fixtures and large building mechanical equipment such as evaporative cooling towers, as well as outdoor water use, such as irrigation systems. The Environmental Protection Agency’s “WaterSense at Work” publications compile many best management practices for saving water and money in government, commercial, and institutional buildings.

Saving water has many benefits:

• Minimizing water and sewer costs (and saving taxpayer dollars, in the case of government buildings)
• Reducing energy needed to treat, pump, heat, and/or cool water in buildings
• Reducing costs and stress on sewer and water treatment infrastructure
• Reducing the impacts of drought and water scarcity, while freeing up more water for other users, including American farmers, homes, streams, and wetland ecosystems.
• Paying close attention to water usage patterns and trends may reveal infrastructure problems such as faulty equipment

Water Data Results

Water use for each building is represented as water use intensity (WUI), calculated as the total gallons consumed per gross square foot of space. These results demonstrate that GSA’s high-performance buildings are more water efficient than both GSA’s legacy stock buildings and average commercial office buildings.

Specifically, results show that over a two-year average:

• High-performance buildings’ WUI was 29% lower than GSA’s legacy stock buildings
• High-performance buildings’ WUI was 38% lower than the ENERGY STAR® Portfolio Manager 2023 (Portfolio Manager) office building median
• GSA’s legacy stock buildings’ WUI was 13% lower than the Portfolio Manager median
• High-performance buildings used 3.4 fewer gallons per gross square foot per year than legacy stock buildings

Based on these findings, if a hypothetical average-sized legacy stock building were as water-efficient as GSA’s high-performance buildings, one building alone would save 620,000 gallons annually compared to a legacy stock baseline — almost enough to fill an olympic-size swimming pool. Water cost savings opportunities could exceed $3 million per year if all legacy stock buildings included in this study were to match the WUI of GSA’s high-performance buildings.

Building operating expenses are the costs associated with keeping a building maintained and functional. GSA collected available data for the following three categories, which comprise most of a building’s regular operating costs:

• Operations and Maintenance (O&M) Expenses: services that keep buildings in working order, such as regular mechanical equipment maintenance and general building upkeep
• Cleaning Expenses: cleaning the building, maintaining its grounds, taking out waste, and removing snow
• Utility Expenses: total building utility costs, including electricity, natural gas, water, and steam

Building operating expenses data results

Building operating costs were calculated as total dollars per rentable square foot for the three cost categories above. High-performance buildings outperformed GSA’s legacy stock buildings in all building operating expense categories. On average, high performance buildings saved $.60 per RSF in total annual operating expenses. GSA was unable to identify a current and appropriate industry-recognized benchmark for building operating expenses.

For individual expense categories, on average:

• High-performance buildings cost $0.27 less per rentable square foot in cleaning expenses, $0.27 less per rentable square foot in O&M expenses, and $0.07 less per rentable square foot in utility expenses, compared to GSA’s legacy stock.

Municipal solid waste (MSW) generated by building occupants, operations, and small modernization activities is disposed into refuse bins and hauled away in the form of landfilled waste or diverted recycling. MSW disposal costs are incurred by property owners and frequently passed on to tenants. Waste diversion reduces MSW hauling expenses, or can even generate revenue, since some waste management firms remove recycled materials for a discounted or nominal cost, or pay building owners like GSA for the value of recycled materials. The U.S. Environmental Protection Agency tracks the national average costs that landfills charge for waste disposal, known as tipping fees. Since the 2018 study, the national weighted average tipping fee has increased by nearly 17% to $57.63 per ton. The 361 buildings with available waste data in this study generated over 21,000 tons of solid waste in FY24, representing over $1.2 million dollars per year in waste hauling expenses, if all the MSW materials were landfilled (The Environmental Research & Education Foundation, 2023).

Solid waste data results

GSA collects solid waste and waste diversion data for buildings in its inventory. The figure below shows the percentage of MSW diverted from landfills for high-performance buildings and legacy stock buildings. High-performance buildings must maintain annual waste diversion rates of at least 50%. Both GSA’s high-performance and legacy stock buildings exceeded this target in FY23 and FY24, with high-performance buildings diverting 5% more solid waste compared to legacy stock buildings. GSA was unable to identify an industry-recognized benchmark for waste diversion percentage. In FY23 and FY24, high-performance buildings cumulatively saved over $826,000 in waste disposal fees based on the national tipping fee average, assuming cost avoidance by diverting materials from landfills.

GSA administers a Tenant Satisfaction Survey (TSS) to all federal employees in GSA-owned and leased buildings annually. The survey’s goal is to assess satisfaction with the building and how it is managed. Tenants are asked to rate their level of satisfaction with building cleanliness, indoor air quality, lighting, noise levels, and thermal comfort on a scale of one to five, with five being most satisfied. For a comparative benchmark, GSA used the Occupant Indoor Environmental Quality Survey from the Center for the Built Environment (CBE) at the University of California in Berkeley.

Tenant satisfaction data results

The figure below illustrates average tenant satisfaction ratings across five major TSS categories for high-performance and legacy stock buildings for FY 2023–2024, as well as the CBE benchmark.CBE’s Occupant Indoor Environmental Quality Survey utilizes a numerical likert scale from 1-7 compared to GSA’s 1-5 rating for the TSS. CBE’s benchmark values were adjusted downward to fit within the 1-5 rating scale for comparison to the TSS scores.

• TSS responses for occupant comfort and building features show that high-performance buildings have average satisfaction rates for all metrics that are equal to or greater than legacy stock buildings.
• The relative performance of high-performance buildings in the categories of lighting and noise levels has improved since the 2018 version of this study was completed.
• GSA’s high performance buildings exhibit higher average overall satisfaction across all categories compared to CBE benchmarks.