New tool to guide the design and construction of sustainable buildings

The market for green building materials is expected to skyrocket over the next five years, driven by an urgent need to build structures that can withstand more intense weather conditions and offer a lower carbon footprint. But until now, there was no way to compare base materials and understand the impact of using them.

Today, Northwestern University and the World Wildlife Fund (WWF) have partnered to develop an international tool that helps construction industry professionals make environmentally responsible decisions when selecting, supply, use and disposal of building materials. Originally created to guide disaster recovery and reconstruction, the Selection and use of building materials: an environmental guide (BMEG) examines environmental impacts, material alternatives, and design and construction best practices.

WWF first created this tool following the 2015 earthquake in Nepal, which severely damaged the country’s infrastructure and put great pressure on resources. The BMEG has provided a good practice guide to minimize the likelihood of future disasters caused by deforestation, erosion, landslides and floods. Building on the framework created for Nepal, WWF and the Institute for Sustainability and Energy at Northwestern (ISEN) began collaborating in 2017 to further develop the BMEG as a decision support tool.

The BMEG consists of a database covering more than 50 construction materials and their mechanical, thermal, electrical and durability properties. The guide emphasizes the lifespan of materials, considering environmental and ecosystem impacts at every stage – from extraction to storage and disposal. According to WWF Senior Researcher and ISEN Visiting Researcher Missaka Hettiarachchithe guide also offers enhanced best practices for using materials.

“The guide provides government agencies, businesses, NGOs and community organizations with the tools to responsibly select, use and dispose of building materials,” Hettiarachchi said. “Incorporating environmental considerations into the construction industry benefits both people and nature.”

The database provides a detailed overview of the impact of a chosen element, including its carbon footprint, toxicity, embodied energy, disposal, reuse, recyclability and approximate price.

Soon, users will be able to enter desired material quantities and specifications into an algorithm that will provide recommendations for material combinations.

The BMEG research team, which includes North West engineering professors Andreas Waechter and Gianluca Cusatis, hopes to embed a building model and optimization algorithm into the materials database to facilitate smoother decision-making and provide a balance between cost reduction and environmental impacts. The machine learning model they are building will create quick, practical, cost effective and environmentally friendly suggestions in an otherwise overwhelming task of disaster recovery.

“Selecting the right materials for rebuilding a building is a complex process that can involve dozens of competing considerations and trade-offs,” Waechter said. “This includes sustainability and climate impacts as well as material costs. We are developing a versatile computational tool that uses mathematical optimization and detailed construction models and enables rapid comparisons of options in the decision-making process. Our approach is truly unique.

Waechter is a professor of industrial engineering and management science at the McCormick School of Engineering, and Cusatis is a professor of civil and environmental engineering at McCormick. The machine learning team also includes Northwestern Ph.D. students Niloufar Izadinia and Elham Ramyar.

William Miller is Professor of Chemical and Biological Engineering at McCormick and Director of the Engineering Center for Sustainability and Resilience (CESR). He co-leads the BMEG project with WWF and ISEN with stephen carrProfessor Emeritus of Chemical and Biological Engineering and Materials Science and Engineering.

ISEN has been leading the formal partnership agreement with WWF on behalf of the University since 2018, and BMEG is the latest collaboration between the two organisations. The WWF collaboration is led by Hettiarachchi, who is visiting Northwestern from WWF’s Environmental and Disaster Management Program. Financial support for BMEG graduate research was provided by the Resnick Family Social Impact Fund at ISEN and by WWF. Additional support for the optimization project was provided by Leslie and Mac McQuown.

Abdul J. Gaspar