An Architecture Firm’s Push To Build Net-Zero Apartments—On A Budget
Share Button

An Architecture Firm’s Push To Build Net-Zero Apartments—On A Budget

Philadelphia’s Onion Flats is constructing low-cost buildings that use design, mechanical equipment and residents’ behaviour to slash fossil fuel consumption.

By RUSSELL GOLD
Thu, Feb 11, 2021 3:52amGrey Clock 4 min

The shiny, onyx-coloured building appears alien in its drab, postindustrial Philadelphia neighbourhood—the love child of a “D-volt battery and the Death Star,” as one local architecture critic put it, admiringly.

Called Front Flats, the four-story building is wrapped on all sides and roof by 492 translucent, double-sided solar panels. The building is airtight and extraordinarily energy-efficient, its developers say.

By driving down consumption and producing electricity from its solar panels, Front Flats is designed to generate its own power. But this isn’t a corporate headquarters where executives can spend lavishly on a showcase edifice. It is 28 apartments, built on a budget for renters who make below the area’s median income. One-bedroom apartments rent for under $1,400, less than the $1,750 average for the neighbourhood, according to rental-listings website Zumper.

Onion Flats, the Philadelphia-based architecture-and-building firm behind Front Flats, is at the forefront of designing low-cost buildings that use design, mechanical equipment and residents’ behaviour to slash fossil fuel consumption.

“As an architect, if I’m not designing buildings that contribute no carbon to the environment then I’m being totally irresponsible,” says Tim McDonald, 56, a principal in Onion Flats. “I might as well be designing buildings that sit on marshmallows.”

Buildings contribute 38% of global greenhouse-gas emissions, including heating, cooling and construction materials, according to the International Energy Agency. The building industry is growing more interested in low-carbon construction, but few architects or contractors have experience with it. Many believe it significantly raises costs. Onion Flats wants to demonstrate that it can be done affordably and at scale, prodding others to follow and policymakers to enact energy-efficient building codes.

Mark Lyles, a project manager at the New Buildings Institute, a nonprofit based in Portland, Ore., that promotes low-carbon construction, says the work by Onion Flats is noteworthy because it ties together on-site renewable energy generation with “deep efficiency.”

Mr McDonald and his partners, he says, are “always asking where can I reduce energy consumption. A lot of his projects are bellwethers for where things are going.”

Onion Flats is one of several firms trying to build very energy-efficient housing. In Manhattan’s East Harlem neighbourhood, a 709-unit affordable housing development called Sendero Verde is under construction; it is intended to be among the most energy-efficient multifamily buildings in the world. In Portland, Ore., a 10-story, 127-apartment retirement community is slated to start construction this spring, and is expected to use up to 60% less energy than a typical multiunit building.

Onion Flats is a family affair. Two of Mr McDonald’s brothers, Patrick and Johnny, are also principals, as is Howard Steinberg, a friend since seventh grade in suburban Philadelphia.

Front Flats is its most ambitious attempt at a “net zero” building—a structure that throughout a year generates as much energy as it consumes. The solar skin—which is 60cm away from the windows and exterior—generates electricity, keeps the building cool in the summer by blocking the sun, and provides privacy to tenants. “You can’t see into people’s apartments, but they can see you,” Mr McDonald says.

The building, which opened in January 2020, doesn’t have a natural gas line and uses electricity for heat and hot water. From January through June, it generated more electricity than it needed and sold the excess onto the local power grid, Mr McDonald says. In July, August and September, it drew more kilowatt-hours than it generated. Overall, it is still ahead, Mr McDonald says, but since the pandemic slowed leasing and the building wasn’t fully occupied until the fall, the true test of whether the building is net zero will come this year with apartments full of people charging their mobile phones and playing on game consoles.

The firm has built several residential buildings in Philadelphia over the years and plans to keep going. The principals have learned that actual energy consumption is often greater than what the models predict. The culprit is “plug load”; people plug in bigger televisions and more electricity gobbling devices than expected.

About a mile south of Front Flats, Onion Flats built another apartment building called the Battery which attempts to tackle this problem. LEDs on the outside of the Battery are connected to particular apartments, although which light connects to which isn’t obvious to passersby or residents. When an apartment is using less electricity than its share of what is being generated, it glows green; otherwise, it glows red. The system, after encountering a software problem, is expected to go online this year.

After building its first government-subsidized, ultra energy-efficient townhouse for low-income residents in 2012, Onion Flats lobbied the Pennsylvania Housing Finance Authority, a state agency that distributes federal low-income tax credits, to consider an energy efficiency standard known as “passive house” construction when determining which builders were awarded the coveted credits. “We said ‘If we can do this, why can’t other developers’?” says Mr McDonald. After one meeting, the state agreed to give developers extra consideration for using a passive house design, beginning in 2015. (Onion Flats didn’t use the credit for Front Flats.)

The passive house projects didn’t cost much more to build than traditional apartment buildings—despite costing considerably less to heat and cool, according to an analysis of construction costs for residential projects over the past five years that the authority performed at the request of The Wall Street Journal.

“Not only is that encouraging, but the end result should be lower utility costs for the life of these passive house apartment buildings,” Robin Wiessmann, executive director of the agency, said in a statement. Tenants at Front Flats pay US$40 a month for utilities. Fifteen states are copying Pennsylvania’s approach and have begun using incentives to encourage more super-efficient apartment buildings.

Mr McDonald says he hopes that buildings that generate their own electricity will become commonplace.

“People don’t say, ‘I want to be known as an architect that has bathrooms in all our buildings.’ No, that’s just a given,” he says. “Being green, being sustainable, being carbon-neutral, should just be what it means to be a good architect.”



MOST POPULAR

What a quarter-million dollars gets you in the western capital.

Alexandre de Betak and his wife are focusing on their most personal project yet.

Related Stories
Property
I.M. Pei’s Son Speaks of His Father’s Legacy of Creating ‘Places for People’ Ahead of a Retrospective in Hong Kong
By ABBY SCHULTZ 12/06/2024
Property
THE EAST COAST CAPITAL SETTING THE PACE IN THE AUSTRALIAN REAL ESTATE MARKET
By Robyn Willis 06/06/2024
Property
Penthouse by Dubai’s Iconic Burj Khalifa Sells for AED 139 Million
By LIZ LUCKING 05/06/2024
By ABBY SCHULTZ
Wed, Jun 12, 2024 5 min

I.M. Pei was the confident visionary behind such transformative structures as the Bank of China Tower in Hong Kong and the Louvre Pyramid in Paris, but he was also humble, and for years resisted a retrospective of his work.

Pei, a Chinese-American architect who died in 2019 at 102 , would always protest any suggestion of a major exhibition, saying, “why me,” noting, too, that he was still actively at work, recalls his youngest son, Li Chung “Sandi” Pei. A decade ago, when Pei was in his mid-to-late 90s, he relented, finally telling Aric Chen, a curator at the M+ museum in Hong Kong, “all right, if you want to do it, go ahead,” Sandi says.

A sweeping retrospective, “I.M. Pei: Life Is Architecture,” will open June 29 at M+ in the city’s West Kowloon Cultural District. The exhibition of more than 300 objects, including drawings, architectural models, photographs, films, and other archival documents, will feature Pei’s influential structures, but in dialogue with his “social, cultural, and biographical trajectories, showing architecture and life to be inseparable,” the museum said in a news release.

As a Chinese citizen who moved to the U.S. in 1935 to learn architecture, Pei—whose full first name was Ieoh Ming—brought a unique cultural perspective to his work.

“His life is what’s really interesting and separates him from many other architects,” Sandi says. “He brought with him so many sensibilities, cultural connections to China, and yet he was a man of America, the West.”

Facade of the Bank of China Tower in Hong Kong in a photograph commissioned by M+ in 2021.
© South Ho Siu Nam

Pei’s architectural work was significant particularly because of its emphasis on cultural institutions—from the East Building of the National Gallery of Art in Washington, D.C., to the Museum of Islamic Art in Doha, Qatar—“buildings that have a major impact in their communities,” Sandi says. But he also did several urban redevelopment projects, including Kips Bay Towers in Manhattan and Society Hill in Philadelphia.

“These are all places for people,” Sandi says. “He believed in the importance of architecture as a way to bring and celebrate life. Whether it was a housing development or museum or a tall building or whatever—he really felt a responsibility to try to bring something to wherever he was working that would uplift people.”

A critical juncture in Pei’s career was 1948, when he was recruited from the Harvard Graduate School of Design (where he received a master’s degree in architecture) by New York real estate developer William Zeckendorf.

With Zeckendorf, Pei traveled across the country, meeting politicians and other “movers and shakers” from Denver and Los Angeles, to Philadelphia, Washington D.C., Boston, and New York. “He became very adept at working in that environment, where you had to know how to persuade people,” Sandi says.

During the seven-year period Pei worked with Zeckendorf, the developer fostered the growth of his architecture practice, supporting an office that included urban, industrial, graphic, and interior designers, in addition to architects and other specialists, Sandi says.

When Pei started his own practice in 1955, “he had this wealth of a firm that could do anything almost anywhere,” Sandi says. “It was an incredible springboard for what became his own practice, which had no parallel in the profession.”

According to Sandi, Chinese culture, traditions, and art were inherent to his father’s life as he grew up, and “he brought that sensibility when he came into America and it always influenced his work.” This largely showed up in the way he thought of architecture as a “play of solids and voids,” or buildings and landscape.

“He always felt that they worked together in tandem—you can’t separate one from the other—and both of them are influenced by the play of light,” Sandi says.

View of the National Center for Atmospheric Research, on the mesa, in a photograph commissioned by M+ in 2021.
© Naho Kubota

Pei also often said that “architecture follows art,” and was particularly influenced by cubism, an artistic movement exploring time and space that was practiced in the early 20th century by Pablo Picasso, Georges Braque, and the sculptor Jacques Lipchitz, among others. This influence is apparent in the laboratory at the National Center for Atmospheric Research in Boulder, Colo., and at the Everson Museum of Art in Syracuse, N.Y. “Those two buildings, if you look at them, have a play of solid and void, which are very cubistic,” Sandi says.

Yet Sandi argues that his father didn’t have a specific architectural style. Geometry may have been a consistent feature to his work, but his projects always were designed in response to their intended site. The resulting structure emerged as almost inevitable, he says. “It just was the right solution.”

Pei also intended his buildings “not only to be themselves a magnet for life,” but also to influence the area where they existed. “He never felt that a building stood alone,” Sandi says. “Urban design, urban planning, was a very important part of his approach to architecture, always.”

After he closed his own firm to supposedly “retire” in the early 1990s, Pei worked alongside Sandi and his older brother, Chien Chung (Didi) Pei, who died late last year, at PEI Architects, formerly Pei Partnership Architects. Pei would work on his own projects, with their assistance, and would guide his sons, too. The firm had substantial involvement in the Museum of Islamic Art, among other initiatives, for instance, Sandi says.

Working with his father was fun, he says. In starting a project, Pei was often deliberately vague about his intentions. The structure would coalesce “through a process of dialogue and sketches and sometimes just having lunch over a bottle of wine,” Sandi says. “He was able to draw from each of us who was working on the project our best efforts to help to guide [it] to some kind of form.”

The M+ retrospective, which will run through Jan. 5, is divided into six areas of focus, from Pei’s upbringing and education through to his work in real estate and urban redevelopment, art and civic projects, to how he reinterpreted history through design.

Sandi, who will participate in a free public discussion moderated by exhibition co-curator Shirley Surya on the day it opens, is interested “in the opportunity to look at my father anew and to see his work in a different light now that it’s over, his last buildings are complete. You can take a full assessment of his career.”

And, he says, “I’m excited for other people to become familiar with his life.”