Concentration of CO2 in the Atmosphere

The “Greenest Building” in Portland, Maine

Bayside Anchor apartments includes 167 rooftop solar panels to produce 70,000 kWh of clean electricity. Photo: Matthew Drost, courtesy of Avesta Housing.

Bayside Anchor apartments includes 167 rooftop solar panels to produce 70,000 kWh of clean electricity.
Photo: Matthew Drost, courtesy of Avesta Housing.

By Barbara and Greg Whitchurch

It might very well be downtown Portlands greenest building — especially the exterior, which is painted various shades of bright green. But whats going on beneath its surface and inside its walls is what makes this building truly green.

Bayside Anchor is Portlands first multifamily affordable housing apartment building to be rated by the Passive House Institute US (PHIUS) as PHIUS+ certified. The 38,000 square-foot structure contains 45 housing units (36 affordable, 9 market rate), a common room, library, and a laundry room. It brings 45 new affordable homes to the city of Portland at a time when high rents and 1% vacancy rates are leading to a city-wide housing crisis.

The Portland Housing Authority (PHA) has various sites in Portland with under-utilized land and parking lots, and the Bayside Anchor site was just such a parking lot. Bayside Anchor was created through a unique partnership between non-profit Avesta Housing and the PHA. They envisioned this project as a catalyst for future redevelopment and reimagining of hundreds of units of public housing in East Bayside.

Bayside Anchor was designed by Kaplan Thompson Architects and built by Wright-Ryan Construction. The project was built to the Passive House standard, specifically to the PHIUS+ low-energy standard, which is the highest energy standard applicable to new construction. Bayside Anchor is also socially innovative, providing a hub for services for low-income residents in East Bayside and giving the project its name as a stabilizing “anchor” for the community. This was accomplished by integrating a Head Start classroom, Housing Authority offices and a community police station on the ground floor, making it a true “anchor” of the neighborhood.

A bit of history about the collaboration. In 2013, Kaplan Thompson Architects partnered with the PHA, Avesta Housing, and Wright-Ryan Construction to win the “Lowering the Cost of Housing” national design competition, sponsored by Deutsche Bank and Enterprise Community Partners. Ultimately, the project was funded by loans and subsidies from various sources, and the City of Portland. It is the first new building commissioned by the PHA in over 40 years.

The team is very proud of the fact that they were able to complete this project to this extremely high standard for only $142 per square foot — about 20% less than typical construction costs for apartment buildings of this type in downtown Portland. The building thus achieved the maximum affordability “points” under the current Maine State Housing Authority scoring system.

Upper “water garden” stage of the multi-level storm water drainage system. Courtesy photos.

Upper “water garden” stage of the multi-level storm water drainage system. Courtesy photos.

Details for the Nerdy Among Us

The building is wood-framed throughout, with cellulose wall insulation, sheathed with Advantech high-performance exterior sheathing. Meticulous air-sealing achieved 0.05CFM50/square foot (or 0.37ACH50, which slightly exceeds the PHIUS+ standard), compared to the more typical 0.25CFM50/square foot. This superior air-tightness is balanced by the installation of a continuously operating, fresh-air heat recovery ventilation system to all rooms. The system used was from Renewaire. This leak-free building enclosure will ensure that the building will offer long-term affordability by incurring minuscule heating bills. Other sustainable features include storm water collection and a community garden.

On top of all that (literally) is a 56-kilowatt rooftop solar PV array, consisting of 167 solar panels installed on ballasted rack mounts by ReVision Energy, based in Portland.

Combining the very low cost target with the ambitious goal of Passive House certification drove the development team to design a highly organized construction management process. The architects/builders collaborated at every stage of this construction — a procedure that has proved essential over the last few years in constructing highly energy-efficient buildings.

How do Greg and I know all this? We attended the NESEA (Northeast Sustainable Energy Association) Pro Tour of Bayside Anchor on April 7, 2017. (It is part of their series of Building Energy Pro Tours.) If you ever want to learn how to conduct a really organized, informative and fun tour, we suggest you attend one of their Pro Tours! It began with refreshments and an introductory overview, presented by Bayside Anchor co-developer Jay Waterman (Portland Housing Authority), and architect Jesse Thompson (Kaplan Thompson Architects).

We then traveled by bus to the project site, where we were divided into groups and rotated through five content-specific stations, each with its own expert presenter. This smoothly-engineered tour allowed for close-up viewing with no crowding, presentations by experts who were involved in the actual planning and construction, and plenty of time for Q and A after each mini-presentation.

At the end, we were bussed back to the host site, where we were fed a lovely lunch, followed by coffee, dessert, and more opportunities for networking with the team. All in all, it put our clumsily-designed tours that we have offered of our own Passive House ( pretty much to shame. The series continues across New England into the fall of 2017. More information on this Pro Tour series is available at The November tour is ten miles up the road from our house:

Barb and Greg Whitchurch are board members of VT Passive House and owners of a net-zero passive house, a Leaf & a Prius in Middlesex, VT,

Many thanks to our Sponsors:

Avesta NW logo combo_Aug 2017_VN

Portland Housing Authority logo



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