We cannot meet our climate goals without utilizing our greatest built and cultural assets: existing buildings. With many cities aiming to become carbon-free by 2050—and, in Boston, with 85 percent of the floorspace the city will need already built—we must embrace existing buildings as critical to climate action.

In this spirit, throughout the summer, the BSA community explored approaches to existing buildings as climate solutions, and underscored the urgency with which we need to develop and share strategies in order to respond to our climate crisis.

Check out conversations on a variety of project types, find strategies and solutions for your work, and share with your colleagues and clients!

Matter & Opinion: Existing Buildings

This series of discussions paired client-and-designer teams to speak about housing (residential and multifamily); education facilities (higher education and K-12); and workplaces. The projects presented illustrated both the inherent environmentalism of reuse, through the reduction of embodied carbon emissions and other impacts, as well as lessons learned, which will inform future sustainable strategies for existing buildings.

Hurdles to reuse that were discussed included:

• time spent trying to navigate and comply with local, state, and federal preservation processes, especially for structures designated historic;
• a disconnect between municipal preservation and sustainability agendas;
• limited financial incentives for designated historic sites and especially for existing buildings not deemed historically significant; and
• an inability to apply one-size-fits-all solutions, since existing buildings do not offer blank slates but rather compelling yet complicated sets of constraints.

In addition to hurdles, the series discussed the benefits of reuse and renovation of existing buildings, which included:

• time saved from bypassing digging, pouring foundations, building new, and potential community pushback;
• embodied carbon reduced and environmental impacts avoided; and
• the inherent connections to community—both the physical connections to existing systems of transportation, education, and commerce, as well as the intangible connections to the people who have lived in or with a building over its lifetime.

The series did not discuss potential solutions that new and developing technologies might offer for sustainable existing buildings. Among new approaches to panelized HVAC for existing buildings is the customizable Hydronic Shell Technologies.

PT Technologies, an entity of Placetailor, is also developing a retrofit panel, the PT Panel—this one with a special focus on healthy and low-carbon materials.

Though we have no one-size-fits-all solution for sustainable existing buildings, designers and clients shared some strategies that practitioners can apply to future work. While deep energy retrofits have often been called for, consider shallow energy retrofits—tactical addition of insulation. In order to demonstrate embodied carbon costs and reductions, complete a life cycle assessment (LCA) for all projects. Also consider how the life of a building is defined, and the timeframe that you are accounting for. The urgency of our climate crisis requires urgent mobilization within an abbreviated timeframe, while the endurance of a building should extend well beyond 2030 or 2050. Perhaps most important is doing existing building work that is meaningful for its occupants—a sustainable building must be one that people appreciate and care for enough to become its stewards.

Want to dive deeper? You can view all session recordings here.

Or want to explore existing buildings from another angle? Check out the additional summer series and sessions on existing buildings below.

REOPENINGS

A three-part series on new architecture in or in addition to existing buildings.

View the recordings here.

CLF Boston Impact series: Renovation/Preservation

One in a seven-part series on embodied carbon.

View the recording here.

Committee on the Environment (COTE): Existing Building Design for Sustainability on a Budget—Anonymous Hall

A knowledge community meeting about executing sustainable existing building projects on a budget.