Alan Weisman’s book The World Without Us (Picador, 2007) offers a provocative speculation about our planet’s future in the wake of humanity’s disappearance. In some ways, current COVID-19 stay-at-home orders have precipitated a version of Weisman’s vision. Today, office buildings, museums, theaters, restaurants, sports facilities, university campuses, and schools are vacant. But it turns out that the act of maintaining these structures in our absence still poses significant fiscal and environmental costs to society.
While the spread of the novel coronavirus has led to a decrease in greenhouse gas production—according to a CarbonBrief article, COVID-19 “could trigger the largest annual fall in CO2 emissions”—experts are surprised that emissions haven't fallen more sharply. One cause could be the resources that commercial buildings require, even while they are vacant. In the recent GreenTech Media article “Why Empty Office Buildings Still Consume Lots of Power During a Global Pandemic,” author Simon Evans points to on the constant flow of resources—including air, water, and electrons—on which our buildings are designed to rely. In the case of emergency lighting and elevators, the rationale for ongoing use of energy is sensible because these features must remain active even in unoccupied structures. A convincing argument can also be made for the continued operation of data centers and servers that house critical information. However, other high energy consumers are problematic.
One major power draw is heating, ventilation, and air conditioning (HVAC) systems, most of which are designed to continue circulating air and water to avoid an unhealthy buildup of chemicals, dust, and corrosion. These systems must also remain operational to remove the volatile organic compounds, such as formaldehyde, from off-gassing materials (also a design failure). Another energy demand is plug loads from computers, appliances, and other devices left behind by occupants that are still drawing power. San Francisco–based Hatch Data, which provides energy monitoring services for commercial real estate, reports that HVAC systems comprise about a third of building energy use, with an equivalent amount associated with plug loads. Beyond these, the primary power use is non-emergency lighting, which accounts for 15% to 20% of energy use in a building and can easily be shut off.
It is alarming that the countless buildings we no longer inhabit are still utilizing approximately 80% of their typical resources. This revelation emphasizes the high operational cost of buildings—occupied or not—and reinforces the fact that they should be viewed more as a collection of services than as static objects. This understanding also highlights the interdependency between architecture and people regarding environmental impact. In their book Our Ecological Footprint (New Society Publishers, 1996), planners Mathis Wackernagel and William Rees explain that sustainability depends on the rate of consumption, not consumption alone. “For example, it might be sustainable to operate a gas-guzzling Rolls Royce if it were shared among 20 friends, and maintained for a long time,” they state. “On the other hand, it might be unsustainable for everybody to own an electric car.” By this logic, buildings with a continuously high human occupancy represent a more responsible use of resources than vacant ones, even if the latter are more environmentally efficient.
The COVID-19 crisis has taught us to plan for similar eventualities in the future, prompting the reconsideration of unneeded energy demands in uninhabited structures. The capability to safely curtail, or at least severely reduce, the flow of unnecessary building resources should be a priority. Smart HVAC approaches, like demand-controlled ventilation, adjust airflow based on occupancy and indoor air quality, as opposed to conventional open-loop systems. A return to simple, passive ventilation strategies such as operable windows would also be a welcome addition in many fixed-aperture commercial buildings today. Smart power strips, including remote-controlled and motion-sensing variants, should be used to eliminate vampire (phantom) power, as well as to shut off unneeded plug loads. And to meet the remaining required demands of emergency lighting and servers, building-integrated photovoltaics and other renewable energy systems can be installed to achieve net-zero operations.
During this time of social distancing, it is tempting to view society’s enhanced environmental performance as a success. However, quite a different story has emerged. If anything, we should be saving significantly more energy. Rather than celebrate our reduced climate impact, we should use the revelation of a systemic failure to improve building design and operations in the future.
