A software program designed by researchers at the Massachusetts Institute of Technology could eventually help architects and engineers reduce their buildings’ greenhouse gas emissions by 75% without limiting their flexibility in design choices.
The program helps designers integrate lifecycle assessment into the design process instead of waiting until construction is underway, according to Jeremy Gregory, executive director of MIT’s Concrete Sustainability Hub, which developed the program.
“Approaches for lifecycle assessment for buildings have existed for quite a while, but they usually require a lot of details in order to do the lifecycle assessment. Basically, you need to know every type of material that’s being used and the amount of material, and you need to have details on energy consumption,” Gregory said. “As a consequence, if a lifecycle assessment is done at all, it’s usually done pretty close to the end of that design process when a lot of the decisions have already been made.”
Lifecycle assessment is a quantitative approach to evaluating the environmental impact that a product or process will have, Gregory explained, from extracting materials, manufacturing them into a product, constructing and maintaining a building, and finally demolishing it at the end of its lifespan.
Typically, LCA in the building industry is applied to products or materials only, he said, not the entire lifecycle. However, Gregory noted that energy consumption accounts for 80% to 90% of a building’s overall carbon footprint.
The Hub’s goal was to find a way to integrate the building material and energy consumption analyses in a way that could be used early in the design process so that architects and engineers could use the analysis to guide their decision making.
To do that, Gregory said, “we had to come up with a framework by which we could define the inputs to a lifecycle assessment based on attributes that building designers were already using.”
One of the challenges is that sometimes in the early design phase, designers don’t have specific inputs for every piece of data. The program allows users to enter a range of data, and the analysis includes uncertainty in its results.
“Essentially, we run thousands of simulations, and in each simulation we randomly design a house that’s within those constraints that the designer has set,” he explained. The program identifies the factors that had the biggest impact on a simulation’s outcome, letting designers “triage” their designs.
“What we find is that there’s a lot of data that goes into these analyses, but most of the data doesn’t matter,” he said. “This triage allows us to say you could probably leave most of this underspecified, but there are a few things you should specify that allows you to lower that uncertainty.”
The program is still in a proof of concept phase, Gregory said. “We’ve created something that works, but it’s not something that is particularly user friendly or, more importantly I think, integrates well with the tools that architects are using.”
Integration is key to successfully implementing new technology. Now, Gregory and his team are working on turning their program into a plugin or app that can be integrated into current design software APIs.