Structural is the longest lasting component of a building, designed to meet codes that address geological and environmental risks. Yet as we see with growing research, climate is changing and many codes may not be keeping up with evolving environmental risks.
Designing resilient structural systems to address climate change is more complex than simply increasing load capacity—subject to either over-guessing or under-guessing future impacts.
To keep the guesswork out, we conducted a research study to better understand the impact of climate change on building loads. Part of HGA’s in-house Research Council Micro-Grant program to research design problems, the structural study examined current climate data to determine if codes based on historic data should be modified.
Using data from NOAA and other national and regional climate resources, we looked at how climate change could impact severe weather trends. The goal was to understand the quality of available information and how we could use this to predict potential risk on structure.
For instance, national temperature data since 1970 records an upward trend, resulting in more atmospheric moisture—potentially leading to heavier rain or snow loads and stronger storms with higher winds. Yet when we examined regional wind speed at such recording stations as the Minneapolis-St. Paul National Weather Service, we noticed a downward trend since 1938. The comparison illustrates that different data is not necessarily compatible and can vary regionally and nationally. Urban, rural and suburban areas can see wide variations in environmental events.
The structural engineer’s role is to balance the most current national and regional data with the extreme of extremes—700-year events—to design resilient systems that sustain their integrity long-term. Through on-going research, we can more accurately evaluate the quality of information we have and strategize how it applies to changing conditions.
When planning structural system with your engineer, consider the following:
- Look beyond standing codes for current data.
- Think about how a changing world impacts building loads.
- Employ “no-regret” decision-making to design for today and tomorrow.
- If you only design for what could happen tomorrow, you could be wrong.
Jonathan Wacker, PE, is a structural engineer in HGA's Minneapolis office.