The City of Boston has pledged to reach carbon neutrality by 2050. To determine how to achieve this, the Mayor organised business and civic leaders to produce the Carbon Free Boston study, based on four sectors of greenhouse gas (GHG) emissions – buildings, transportation, waste and energy supply. Arup was selected to lead the buildings sector analysis, with buildings accounting for roughly 75% of Boston’s emissions.

Our sustainability experts began by defining building typologies that broke down Boston’s 86,000+ structures into 15 distinct types in four age ranges, plus a set of models to represent future growth. With 75 distinct typological building models capable of generating highly accurate data, the buildings sector study is the most comprehensive building emissions analysis completed to date for a major urban area and constitutes a new benchmark in energy modelling.

This comprehensive approach allowed Arup’s experts to model scenarios and determine the combination of strategies capable of delivering the most significant reductions. The resulting Carbon Free Boston Summary Report included detailed recommendations on how to transform the building sector through a mix of regulatory requirements, financial assistance and workforce training.

Climate and sustainability services

To determine the most effective interventions, our sustainability experts first needed to find a way to accurately measure the performance of the city’s entire building stock. The four-person Arup team began by defining building typologies that broke down Boston’s 86,000+ structures into 15 distinct types, ranging from office buildings to warehouses to K-12 schools. These 15 types were then further subdivided into four age ranges (pre-1950 through Post-2000s). The team also created an additional set of models to represent future growth that allowed them to model scenarios to determine the combination of strategies capable of delivering the most significant reductions.

With 75 distinct typological building models capable of generating highly accurate data, the buildings sector study is the most comprehensive building emissions analysis completed to date for a major urban area and constitutes a new benchmark in energy modelling.

Landing on the right solutions for Boston’s buildings involved much more than simple number crunching, however. To identify the right strategies, first the team had to ask the right questions. For instance, how was each building type currently performing? How effective were the city’s existing regulations at driving down emissions in various categories? And what combination of policies had the greatest chance of helping the city to achieve carbon neutrality—from a practical, economic and social equity standpoint? Arup’s models allowed these questions to be investigated in depth, providing the data-driven insights needed to inform future policy. 

The buildings sector modelling work done by Arup provides an extremely sophisticated analytical tool to plan for the decarbonisation of Boston’s buildings sector. This analytical capacity will support the city in making the difficult policy choices that will be needed to achieve its targets.

John Cleveland

Executive Director, Green Ribbon Commission