11 E Lenox

This 34-unit multifamily project combined the benefits of mass timber construction with Passive House design to create an energy efficient, low embodied carbon building. The result is a building system designed to be 81 percent more efficient than a conventional baseline equivalent.

Designers used a targeted hybrid approach, an efficient post-and-beam configuration with glue-laminated timber (glulam) beams and columns and cross-laminated timber (CLT) panels combined with prefabricated concrete cores and steel posts at grade, used to keep the building under the high-rise threshold.

Clever detailing also added value. Designers carefully coordinated mechanical system placement to align with the wood structure, which helped them meet the building’s vertical height limitations. They worked to maximize glazed openings which added natural light to the units, and left large expanses of CLT ceilings exposed, both of which provide biophilic benefits. The mass timber system enabled structural and operating efficiencies, and helped the developer meet its sustainability and carbon reduction goals.

11 E Lenox was the first ground-up commercial mass timber building in Boston. The architect estimated that their use of mass timber saved more than 300 metric tons of carbon over conventional steel or concrete alternatives.