Buildings may be carrying a hidden environmental cost that conventional carbon calculations fail to see. A new review from Drexel University argues that life cycle assessments—the standard method used to estimate a building’s environmental impact—often assume that a structure will remain operational throughout its life. That assumption becomes increasingly unrealistic as floods, heat waves, hurricanes, wildfires and other extreme weather events grow more frequent and destructive. According to the research, a building’s environmental footprint should include not only the emissions released during the manufacture of materials, construction, energy use and eventual demolition, but also the resources required to keep it functioning during a disaster and restore it afterward.
The findings, published in the Journal of Industrial Ecology, suggest that resilience and sustainability can no longer be treated as separate design goals. Buildings account for more than a third of global greenhouse gas emissions when construction, operation and related activities are considered. Yet the environmental calculations used to guide design and certification may overlook what happens when a structure is damaged, evacuated or forced to shut down. A building that appears efficient on the day it opens could generate a much larger carbon burden if it becomes unusable after a storm and requires months of repairs, temporary replacement services and energy-intensive reconstruction.
Fernanda Cruz Rios, PhD, an assistant professor in Drexel University’s Howley College of Engineering and Computing, reached this conclusion after conducting a systematic review of 40 studies examining building resilience through life cycle assessment. The studies addressed four major threats: seismic activity, extreme heat, flooding and wind. Life cycle assessment is designed to follow environmental impacts across a product or system’s entire existence. For a building, that can include extracting raw materials, manufacturing steel and cement, transporting components, constructing the structure, supplying electricity and water, maintaining equipment and eventually replacing or demolishing the building. Cruz Rios found that although all of the reviewed studies discussed resilience in some form, most did not quantify the environmental consequences of losing functionality.
That omission is important because resilience is not simply a matter of whether a building collapses. A structure can remain standing yet become unusable if its electrical systems fail, indoor temperatures become unsafe, water enters occupied areas or essential equipment is damaged. A hospital, school or apartment complex may be structurally intact while still being unable to serve its occupants. The review found that many assessments did not measure the materials, energy and infrastructure required to make a building more robust in advance, such as stronger structural components, elevated mechanical systems, flood-resistant interiors, redundant power supplies or backup water systems. They also frequently omitted the time and resources required to return the building to normal operation after an extreme event.
Cruz Rios’s proposed framework addresses this gap by treating functionality over time as a central part of environmental performance. Instead of producing a single carbon estimate based largely on normal operation, the approach follows how a building performs before, during and after a disruptive event. It can account for the additional emissions associated with reinforcing walls, installing backup generators, adding redundant heating and cooling equipment or selecting interior finishes that can be rapidly removed and replaced after flooding. It can also calculate the environmental consequences of downtime, including emergency fuel, temporary shelter, evacuation transportation, replacement medical facilities and other compensatory services needed while the damaged building is unavailable.
The framework also recognizes that a resilience measure may have an environmental cost at the beginning but produce a larger benefit later. A reinforced concrete wall, for example, requires additional material and may increase emissions during construction. A generator or battery system requires manufacturing, maintenance and eventual replacement. However, if those measures prevent severe damage during an earthquake or storm, they may eliminate the need for extensive demolition, reconstruction and the manufacture of replacement materials. A flood-resistant interior design could similarly avoid the carbon emissions associated with gutting walls, replacing flooring and discarding damaged furnishings. In this calculation, the environmental impact avoided through resilience becomes part of the building’s performance rather than remaining invisible.
The difference could be especially significant for critical facilities. Two hospitals may receive nearly identical environmental scores when assessed under conventional methods, even if one is designed to continue operating during a disaster and the other is not. If the less resilient hospital closes for several months after a storm, the community may need temporary treatment centers, emergency generators, fuel deliveries and transportation systems for patients and staff. The damaged facility may also require extensive reconstruction. A hospital designed to remain functional could consume more resources during construction, yet avoid many of those later impacts. Without accounting for operational continuity, conventional life cycle assessment can make the two buildings appear environmentally equivalent despite their radically different real-world consequences.
The research does not propose abandoning current assessment methods. Instead, it presents resilience-related modules that could be added to the life cycle analyses designers already use. The modules could compare the environmental cost of preparing for a specific hazard with the projected cost of doing nothing, while also considering the probability, severity and duration of disruption. This would allow designers to evaluate whether a particular intervention produces a net environmental benefit over the building’s expected lifetime. The model can also incorporate improvements made after an event, recognizing that repairs may either restore the previous level of vulnerability or create a more durable structure capable of withstanding future hazards.
Such an approach could change how buildings are rated, financed and regulated. Environmental certification programs, including Leadership in Energy and Environmental Design, the National Green Building Standard and Green Globes, are widely used to reward lower-impact construction and may influence access to tax incentives. If resilience were formally integrated into these systems, designers could receive credit for measures that reduce future damage and downtime rather than being judged primarily on upfront materials and routine energy performance. The result could be a broader definition of sustainable construction—one that treats durability, recoverability and continued public service as environmental assets. As extreme weather intensifies, the review argues, a building’s true carbon footprint will depend not only on how efficiently it operates under normal conditions, but on how much society must spend in resources and emissions when normal conditions disappear.
Subject of Research: Building resilience within life cycle assessment and the environmental impacts of extreme-weather-related damage, downtime and recovery.
Article Title: Resilience in building life cycle assessment: a critical review and framework for time-integrated functionality
Web References: https://www.unep.org/resources/report/building-materials-and-climate-constructing-new-future; https://www.ncei.noaa.gov/access/billions/; https://www.aia.org/resource-center/building-life-cycle-assessment-practice; https://drexel.edu/engineering-computing; https://drexel.edu/engineering/about/faculty-staff/C/cruz-rios-fernanda/
References: Journal of Industrial Ecology, DOI: 10.1007/s44498-026-00152-7
Keywords: Environmental impact assessment, building construction, architecture, construction materials, carbon debt, extreme weather events, building resilience, life cycle assessment, climate adaptation, sustainable design
