For Green Building, ‘Durable’ Is the New ‘Sustainable’

Reducing the negative environmental impact of buildings — globally one of largest contributors to greenhouse gas — might be even more difficult than expected. New research from Drexel University indicates that, due to the steady increase in damaging extreme weather events each year, designers must begin to consider not if, but how long, their buildings will be rendered inoperable — and how the resources to get it back online will contribute to its overall environmental impact.

In a recently published review of research in the Journal of Industrial Ecology, the author, from Drexel’s Nick Howley College of Engineering and Computing, pointed out emerging gaps in how a building’s total environmental impact is calculated — a process called life cycle assessment — due to the destruction and disruption caused by extreme weather. The comprehensive analysis, which takes into account the greenhouse gas emissions involved with everything from making the building materials, to its construction and its operation, is currently used in rating systems that incentivize environmentally friendly building and design practices.

“If we truly want to reduce the environmental impact of building construction and operation, which currently accounts for more than a third of global greenhouse gas emissions, it is vital that we look at the full picture,” said Fernanda Cruz Rios, PhD, an assistant professor in the Howley College’s School of Engineering, who conducted the research. “More frequent extreme weather events are changing the calculus around what it takes to maintain a functional building — this must be factored in when thinking about resource consumption.”

Cruz Rios conducted a systemic review of 40 studies looking at building resiliency through the lens of life cycle assessment. They fell into four main categories for which resilience was examined: seismic activity, heat, flooding and wind.

Looking specifically for whether or not the research quantitatively integrated resilience metrics in their life cycle analysis, Rios found that although all of the studies addressed some form of resilience, most failed to consider key aspects related to inoperability. These include quantifying what it would take to make a building robust against extreme weather — such as using stronger materials, building redundancy or interoperability into systems — and how quickly and what resources it would take to get it back online after an event.

“These knowledge gaps point to the fact that these assessments are conducted assuming that the building will continue to be operational — the environmental cost of fragility has systemically been underestimated,” Cruz Rios said. “We now know that is not accurate in most cases, so we need to work toward a true-to-life representation of the building’s carbon footprint both when it is operating and when it is drawing on resources to resume operation.”

Based on this analysis, Cruz Rios created a new framework that factors in the environmental costs and benefits of resilience. By using it, designers can weigh the relative cost of taking action to ensure building resiliency against inaction — this may inform their choices around things such as designing concrete walls to withstand seismic activity, installing backup generators or building with interior finishes that can quickly be replaced or modified to restore full occupancy after flooding.

Adapting the life cycle assessment system could also provide a more accurate picture of vulnerabilities in the built environment, which could help to plan emergency response.

“Under current life cycle assessment methods, two hospitals – one designed to keep functioning through a disaster and one that isn't – can end up with nearly identical environmental scores on day one," Cruz Rios said. "But if one goes dark for months after a storm and has to be rebuilt, while the other keeps running, that difference never shows up in how we measure their environmental impact. Being able to design for that resilience, and actually measure what it's worth, is what's missing right now.”

Cruz Rios’s model captures both the environmental cost of compensatory services that must be deployed while a building’s operation is being restored — temporary shelter, emergency fuel, evacuation transportation — as well as the additional cost of designing a building so that it can better withstand extreme environmental challenges. It also considers modifications to improve the building’s resiliency after the event.

The model also credits the damage, repairs and downtime a resilient design choice helps a building avoid altogether. For example, a building that doesn't need to be gutted and rebuilt after a flood never accrues the environmental cost of that rebuild in the first place and that avoided cost counts in the building's favor in Cruz Rios’ model.

According to Cruz Rios, the next step for broad adoption of this expanded model for life cycle assessment would be to have it formally incorporated in environmental design rating systems, such as Leadership in Energy and Environmental Design (LEED), National Green Building Standard or Green Globes — which often come with tax credit incentives for buildings that achieve them.

"This isn't a new system that replaces what designers already do,” Cruz Rios said. “It's a set of modules that plug directly into the life cycle analyses they're already running when a building is designed. Adoption into formal standards will likely take time, that kind of change always does, but I'm already hearing from designers who've noticed this gap on their own and want a way to prove that building for durability is also building sustainably. Right now, the tools don't give them that."

Read the full paper here: https://link.springer.com/article/10.1007/s44498-026-00152-7