Last Updated on December 16, 2023, 6:31 am ET
Libraries have long since led the way in enabling student success; advancing research; and embracing diversity, equity, and inclusion. With this critical role on the campus, they are often among the largest and longest-open spaces on a university campus. Therefore, they demand outsized energy usage. With more scrutiny put on all forms of energy use and a focus on decarbonization across campuses, libraries can once again lead the way. See below, dear reader, for some considerations on why this matters for libraries, what should be measured, and how to begin your decarbonization journey.
I. Why This Matters
Reducing carbon footprint has never been more relevant as local, state, and federal mandates coincide with an increased focus of students on the sustainable practices of a university in their choice of what institution to attend. University leaders have reflected this focus in strategic plans and signed on to large-scale climate commitments.
Libraries’ Leadership Role
University libraries specifically have an outsized role to play here for three reasons. First, university libraries are large, expansive, and heavily climate-controlled facilities operating for extended hours creating significant energy use—and significant opportunities for reduction. Second, university libraries are positioned as flagships that support all students, faculty, and staff on campus and are operated by research-based professionals who want results. Third, libraries are the spaces that students are most satisfied with from functional and experiential perspectives, and this presents an opportunity to earn greater satisfaction with their environmental performance. Libraries are perfectly suited to be leaders in decarbonization efforts.
What’s the scale of the opportunity before us? In our national benchmarking with the Society for College and University Planning, we found four-year public institutions provide 5.8 net square feet of study space per student and private institutions provide 9.7 net square feet of study space, for a weighted average of 7.7 net square feet per student among four-year institutions. If you assume about half of that space is in the library, then we are talking about roughly 143.5 million net square feet of academic library space in the US.
Connecting the Physical Footprint and the Carbon Footprint
Our recent study using sensor data from 38 institutions showed that, while utilization of these spaces has recovered in the last year, they are still not up to their pre-pandemic levels of utilization with an average peak of 42% seats full in 2023 compared to 54% pre-pandemic. This makes the university library a great area of emphasis for campuses striving to reduce energy usage and carbon footprint. (Of course, libraries, especially those with outdated or densely packed seating, can seem “full” well before 100% of their seats, often more like 50%.)
Many higher education institutions have committed to being carbon neutral between 2030 and 2050, meaning they would make no net release of carbon dioxide to the atmosphere. This will require significant operational optimization over time. Measuring and tracking energy use will be a key factor in the success of meeting decarbonization goals. Measuring and tracking will also make this process transparent for users of the buildings and give required data to those implementing carbon-reducing projects.
II. What To Measure
We know from our experience that the most sustainable buildings are the ones loved and used, maximizing the value of the investment made to build and operate that building. Energy use per square foot (energy use intensity or EUI) can be a tricky metric, particularly when comparing buildings that operate 24/7 to those that do not—it can paint a picture of inefficiency when the reality is more complex. So, in addition to tracking energy use (and greenhouse gases, water, and so on) across the square footage of the building, we recommend tracking how many people and how often those people are using the building and evaluating the carbon footprint on an occupancy basis using the metric of energy per hour used. After all, buildings are for people.
What’s Measured Improves
The problem is, library energy use is rarely measured, poorly categorized, and not benchmarked. For example, in the most comprehensive data on energy use, the US Department of Energy’s Commercial Buildings Energy Consumption Survey (CBECS), there isn’t a specific academic library category, only a broad “College/University” category for academic libraries and one for public libraries under “Public Services.” From the CBECS data and the Energy Star Technical Reference, we know that the national median energy use intensity (EUI) measured in kBtu/square foot (SF)/year is 84.3 for college/university buildings and 71.6 for public libraries, compared to 48.5 for a K–12 school, 52.9 for an office building, or 115.3 for a laboratory building.
Reducing Demand and Increasing Electrification
General as they may be, data from the CBECS on university buildings show that about two-thirds of academic buildings’ energy use is in the heating, cooling, and ventilation. We also know that when we look at energy sources nationally, electricity accounts for only about half of the energy used. We must do better on both counts, and we have a long way to go to electrification and decarbonization!
Energy efficiency can be gained by metering and submetering energy use across specific end-uses in a building (such as heating, cooling, humidification, lighting). These data can clearly illustrate what energy is being used for, and facilities teams and engineers can identify opportunities to gain efficiency and reduce operating costs alongside carbon emissions.
Local Laws Driving Change
This varies from region to region and often municipalities are driving change through regulations like New York City’s Local Law 97 (LL97) or Boston’s Building Emissions Reduction and Disclosure Ordinance (BERDO). We recently benchmarked the intensity of carbon emissions of two dozen libraries in Boston in kgCO2/SF/year. They ranged from 0.8 to 9.5, with about two-thirds falling in the range of 4 to 7 kgCO2/SF/year with an average of 5.25 and a median of 5.6. Boston’s BERDO provides maximums in five-year increments: 5.3 by 2030, 3.8 by 2035, 2.5 by 2040, 1.2 by 2045, and 0 by 2050. Starting in 2030, 58% of libraries in our study would need to reduce their greenhouse gas (GHG) emissions to get below the 5.3 threshold, in some cases by as much as 40%.
III. How to Begin
Once we understand space utilization and energy use together, we can start making progress by allocating space more effectively, reducing energy needs, and going beyond the walls.
Improve Space Utilization
To use their space more effectively, libraries can carefully shift space from stacks to study and student-success functions. Our recent study, with the space monitoring company Occuspace, of nearly 40 libraries showed that incorporating student-success functions increased space use by 25% and that there was little relationship between on-site collections and space use (r = 0.2). Libraries may also be able to reduce their physical footprint by moving low-use materials to high-density storage, by rightsizing the workplace to align with hybrid-work needs, and by consolidating underutilized satellite departmental library locations, which our study found are used about 40% less than central locations.
Align Operating Hours with Demand
To reduce the energy use within the spaces they have, libraries can better align their hours of operation to actual demand so they are not heating, cooling, and staffing spaces that are rarely used overnight; 24-hour study zones can ensure that overnight needs are met in a much smaller footprint rather than the entire library. Like many museums have done, libraries can also relax the environmental conditions and criteria for temperature and relative humidity for all but their special collections. Institutions can also do an energy audit of current space and then recommission their buildings to modernize operations and yield energy savings. Vacancy-based building controls can provide further savings. Proper space-utilization data will provide critical insight to this process.
Do More Online
To reduce their physical footprint, libraries can go online and beyond their walls. Partnering with nearby institutions or joining a consortium can result in sharing space, staff, and collections to eliminate redundancies. Online learning can both increase and decrease space needs. About two-thirds of fully online students enroll within 50 miles of home, but when on-campus students take classes online, this can increase library use as they come together to work on projects, study, and watch recorded content. When online learning pulls students away from campus, it can reduce the library’s physical footprint and therefore carbon footprint. In our recent study tracking the carbon footprint of higher education campuses in the era of online learning, we found that the median carbon emissions of an online student are less half that of an on-campus student: 2,200 versus 4,700kg CO2e/student/year.
Decarbonizing university libraries is a broad challenge requiring many skill sets. Fortunately, these skill sets of research, documentation, and success-driven implementation have been core competencies that libraries have relied on to meet every challenge they have faced so far. Now they can use those competencies to lead the way in campus decarbonization.
Editor’s note: If you enjoyed this blog post, consider attending the ARL President’s Institute on “Embracing Sustainability—Libraries Leading the Way” in San Diego, Thursday, February 8. The registration deadline has been extended to Wednesday, January 10. Registration scholarships are available.
