Researchers call for new standards for building in Hawaiʻi’s coastal flood zones

A new study reveals a wide variety of approaches across the U.S. for establishing building elevation guidelines that account for future sea level rise, highlighting a need for more standardized methods. The University of Hawaiʻi at Mānoa research, published in Water, provides a critical resource for policymakers and designers in coastal communities such as Hawaiʻi who are planning for the impacts of climate change.

“With coastal high tide flooding having doubled in the US in the last two decades, it’s clear that we need to build for the future, not just for the past,” said lead author Wendy Meguro, an associate professor in the UH Mānoa School of Architecture and director of the Environmental Research and Design Lab. “Our main suggestion is for policymakers and designers to plan for sea-level rise amounts projected within a building’s lifetime.” 

This research directly supports state and county efforts in Hawaiʻi to adapt coastal communities to the impacts of sea-level rise by informing future building policies. The collaborative project also aligns with UH Mānoa’s strategic goals of fostering faculty-mentored student research that responds to state needs. 

“This research is crucial for supporting community resilience in Hawai‘i,” said Eric Teeples, who was a doctor of architecture graduate student while working on the project and is a co-author of the paper. “Sea level rise is a real threat to many coastal communities, and Hawai‘i is particularly vulnerable. By learning from others, we can develop informed, forward-thinking, and actionable approaches that fit our community.” 

The research team plans to share their findings and gather public feedback at a presentation in late 2025. This event will focus on different methods to determine minimum building elevation to adapt to sea-level rise and seek community preferences to help inform future guidelines and policies for Hawaiʻi, with a particular focus on Honolulu. 

As climate change accelerates, rising sea levels will dramatically increase flood risk, yet methods to establish minimum building elevations for sea level rise are not standardized. Current Federal Emergency Management Agency standards are based on historical flood data and do not account for future sea level conditions. This leaves local governments to develop their own guidance. 

The study identified and compared seven initiatives—ranging from the federal level to municipalities like New York City and Boston—that have developed building elevation guidance incorporating future sea level rise. The authors analyzed key factors such as the starting point for water level measurements, the projected sea-level rise scenarios, and whether the guidelines are required or merely recommended. 

By analyzing these different approaches, the research underscores the potential for more consistent methods and informs decision-making for officials developing their own sea-level rise design flood elevations.

The work was funded by the Office of Naval Research and a grant from the National Oceanic and Atmospheric Administration through the UH Sea Grant College Program. 

Read more about the team’s project at: https://seagrant.soest.hawaii.edu/meguro-adapting-waikiki/