Engineering Inc.; Boston-based Biome Studio, a zero-energy and sustainability consulting group; and Boston-based Pinck and Co. as owner’s representative. The team targeted 192 apartments totaling 174,425 square feet for the DER. CSTO Executive Director Deborah Backus
encouraged the team to envision a “trail- blazing” renovation, aiming for Platinum certification under the Washington, D.C.- based U.S. Green Building Council’s LEED for Homes Midrise program. The team’s chal- lenge was turning a 1960s building made with porous, uninsulated concrete and brick infill (R-3) that featured aluminum slider windows and through-wall A/C units into a modern, tightly constructed multifamily building. Their efforts would help retain the low- and moderate-income rents its resi- dents expected and improve quality of life. In fact, CSTO had already struggled to
retain affordability, having faced the threat of its rents going to market rates at one point in the 1980s. CSTO then acquired the property, and set affordable rents for the next 100 years, helping secure the diversity that is Boston’s South End heritage. However, residents still suffered from high energy bills and uncom- fortable, less-than-healthy living conditions.
A new challenge came to light during de-
sign charrettes conducted early in the proj- ect to evaluate design alternatives. “In some ways, the residents felt alienated from their community,” says Ann Moy, CSTO president and a resident. “The look of affordable hous- ing made the residents feel separate from their increasingly affluent neighborhood.”
the apartments and outdoors. A new boiler and hot-water plant would be added, rated at 94.5 percent efficiency, leading to hydronic baseboards in the apartments. For preheating domestic hot water, a new solar water-heat- ing system would be added to the rooftop. Other major changes would include
swapping out low-efficiency air condition- ers for 9.9 EER Energy Star package units, as well as adding Energy Star refrigerators. The building’s exhaust ventilation system would be renovated by sealing it with a material that is applied to the inside of the ducts via access from the roof and then utilizing constant-air regulator dampers; fresh-air trickle vents also would be added. CFLs or LED lighting would be installed in
A liquid-applied air- and water- control membrane was painted onto the original concrete and brick walls. Then, a mineral-fiber blanket was laid over the mambrane.
With CSTO’s input, the team developed a
scope of work, including a super-insulated shell of R-40 white reflective roofing and R-41 metal façade cladding to be applied directly over existing exterior concrete and brick. New fiberglass casements and French doors (R-5) would replace the leaky aluminum units. Extensive internal air sealing would be applied between individual apartments and between
hallways, lobbies, kitchens, bathrooms and exterior walls. Low-flow plumbing fixtures, including 0.5-gallon-per-minute (gpm) lava- tory aerators, 1.5-gpm kitchen-sink aerators and 2-gpm showerheads, would further reduce energy draw while saving water. Flushometers also would be added to exist- ing toilets, and replacement toilets would be 1.3-gallon-per-flush models. The exterior retrofit strategy was critical
to the project’s success. Completed in May 2012, this project did not displace residents during the extensive construction. “Part of the beauty of a deep-energy retrofit is that it does not require a gut renovation,” Backus says. “This is because the insulation
The 5-inch-thick metal panels from Kingspan feature insulation performance about twice that of wall systems built to current code.