• The building will have zero fossil fuels on-site, including all-electric commercial kitchens and a 95 kW rooftop solar system.

• The project has reduced embodied carbon 60%  through use of a mass timber structure, low-embodied carbon insulation, glazing and healthier, low embodied carbon concrete.

• Instead of fly ash (a toxic by-product of burning coal), Ground Glass Pozzolan (a recycled glass product) has been used in structural and non-structural concrete as an innovation to find more long-term sustainable and healthier solutions for concrete. The use of ground glass pozzolan in structural concrete is a first in Massachusetts.

• Materials were locally sourced to reduce carbon related to transportation and support the regional economy: 40% came from within 300 miles, 55% from within 600 miles, and only ~10% from outside the United States.

• Over 90% of annual rainfall is designed to be managed on site or reused within the building. 

• The facade is designed with bird-safe glass to reduce bird deaths from collisions.

• The adjacent Allstonway provides nearly one acre of biodiverse landscape. During construction, crews uncovered 200 massive boulders that have been integrated with the site design.  Enriched by 75 different plant species, the site offers habitat for butterflies and beneficial insects. More than 110 trees, chosen for longevity and climate resilience, ensure this habitat will continue to thrive into the future. 

The Harvard Heathier Building Academy (HHBA) takes a research-backed, class-based approach to eliminating chemical classes of concern from building products, finishes, and furnishings.  These include per- and polyfluoroalkyl substances (PFAS), chemical flame retardants, and antimicrobials in all 14 interior product categories and more chemical classes where it’s possible to go further, for example, carpet. 

• 100% of products were researched for health.  

• More than 430 of the products installed are the best available on the market (excluding mechanical, electrical and plumbing) 

• More than 260 products have transparency labels, which are like a nutrition label for building product ingredients. 

• Across the 14 HHBA product categories, more than 75 products were installed.

The SBS have operationalized research by Harvard faculty that shows increased outside air improves cognitive function for occupants and reduces disease transmission. The Rubenstein Treehouse provides increased ventilation while balancing energy performance.

• • The project is designed to provide 75% more outside air than required with only a 4% energy penalty  with high efficiency energy recovery and underfloor air systems, known as displacement ventilation.  Displacement ventilation delivers fresh air through the floor, using the natural rise of warm air to lift and exhaust pollutants near the ceiling.   This approach is quieter, more energy efficient, and improves air quality.

Predicted Energy Use Intensity:  61 kBtu/sf/yr

• The building will have zero fossil fuels on site, including all-electric commercial kitchens and a 95 kW solar rooftop system estimated to generate 120 MWh of renewable electricity per year, or ~10% of annual energy use.

• Together with highly insulated walls and high-performance glass, heat recovery and underfloor air systems, these strategies reduce annual operational emissions by 50%.

• Three-quarters of regularly occupied spaces in the building have access to quality natural daylight. Together with lighting controls, daylight reduces lighting energy consumption by more than 50%.

Embodied Carbon Reduction: 60%

Embodied carbon emissions are emissions associated with the manufacturing and transportation of building materials and construction activities. They are locked in by the time the building is completed as compared to emissions from energy consumption which accrue over time. The Treehouse reduced embodied carbon by 60%. Strategies to achieve this include:

• Mass timber structure instead of concrete and steel.

• Using 60% less cement in the concrete without fly ash. Cement accounts for 95% of concrete’s emissions. Instead of replacing cement with fly ash, a coal byproduct with heavy metals, a low-carbon and healthier solution was used: recycled ground glass pozzolan (GGP). The Rubenstein Treehouse is the first project in Massachusetts to use GGP in structural concrete.
• Lower embodied carbon building envelope components including insulation and the glazing system.

Potable water savings: 50%

A changing climate is anticipated to present more extremes in weather events, including increased drought and more intense rainfall events. The Rubenstein Treehouse building is designed to be resilient to changes in climate and restore ecological water flows.

• The stormwater systems are designed to manage 90% of average annual rainfall on site. The biodiverse landscape, bioretention swales, and permeable paving are part of a stormwater management system that collects, cleans, and slows stormwater runoff, reducing flooding and mitigating pollution by removing the sediment, copper, zinc, and phosphorus. 

• Using 50% less potable water.  Part of the stormwater management system includes a 20,000-gallon rainwater harvesting tank that captures rainfall from the roof. This recycled water is estimated to cover all landscape irrigation and more than half the flushing needs. The building integrates water-efficient appliances and low-flow fixtures, ensuring that every drop is used wisely.