dec 10 | GreenSource
The rise of retrofit
by Katharine Logan
The building sector accounts for a whopping 40 percent of greenhouse gas emissions in the US and consumes fully 70 percent of American electricity. While mandatory codes and voluntary checklists are raising the standard for the efficiency of new buildings, well over half of the buildings that will count towards Chicago 2020, PLANYC 2030, and the2030 Challenge are already standing. So if we're to avoid Armageddon 2040, which would mean a lot for the world in 2050, it's time for green retrofitting, the Clark Kent of the building industry, to step into the phone booth.
Building and energy industry analysts an: widely predicting a green retrofit boom. A recent report from McGraw-Hill Construction estimates green building now comprises 5 to 9 percent of the renovation market by value, and predicts this will grow to 20 to 30 percent by 2014, with dramatic growth continuing into the longer term. More conservatively, leading industrial market research firm SBI Energy predicts significant growth in green retrofits 13 percent of the market by 2015, with green building practices in renovations emerging as the new normal in years beyond. Driving the retrofit surge are, on the public side, climate change, energy security, and economic stimulus, and on the private side, cost-benefit analysis and changing norms.
Chicago, a city of some 2.85 million and a selected participant in the Green Capital Global Challenge, provides some great examples - from single-family houses, through major commercial and institutional buildings, to the city itself - of what's possible and what's needed to meet these emerging imperatives.
The Chicago Climate Action Plan identifies the main sources of the city's greenhouse gas emissions as electricity and natural gas consumed by buildings (70 percent) and transportation (21 percent). The plan sets goals to reduce emissions and to adapt to climate changes already under way, and proposes to achieve these goals in ways to improve the city's economy and quality of life.
The overarching goal is an 80 percent reduction below the city's 1990 greenhouse gas emissions level by 2050, with an interim level by 2050, with an interim goal of a 25 percent reduction by 2020. The difference between the city's 2050 trajectory and its 2020 goal is 15.1 million metric tons of carbon dioxide equivalents (MMTC02e). To give a sense of what that figure means - it's about equal to removing 2.8 million cars from the road.
To achieve this goal, the plan sets out five strategies. Energy-efficient buildings are number one. Chicago residential housing units number just over a million, at least 80 percent of which are expected to be standing in 2020. The aim is to achieve 30 percent energy savings in 40 percent of the city's residential housing stock.
Commercial, institutional, and industrial buildings in Chicago number of 23,000. Again, the 20020 aim is a 30 percent energy reduction in 40 percent - or 9,200 - of them. Combined with other strategies, targeted savings in the building sector account for 4.6 MMTCO2e or 30 percent of the 2020 total.
At the residential scale, building heat loss is the most significant energy drain. Heat loss occurs either through direct loss, as air moves through gaps in the building envelope, or through temperature differential, as components of the building envelope conduct heat out. Air sealing addresses direct heat loss and insulation addresses heat loss through temperature deferential. "Those are the two main things we do," says Tom McElherne of DNR Windows, an established Chicago area weatherization contractor. DNR performs a blower door test of a building's air leakage before and after each weatherization project. "If you don't cut that number," says McElherne, "you're not going to cut their bills." Faith Foley, assistant director of the Historic Chicago Bungalow Association, agrees, "You're not going to cut their bills." Faith Foley, assistant director of the Historic Chicago Bungalow Associate agrees: "Air sealing is so crucial in any household, more than insulation even - that's where we're education."
The Chicago bungalow, a brick masonry housing type built between 1910 and 1940 accounts for more than a third of Chicago's single-family housing stock. The bungalow's commonalities and the organization of their owners into an association makes the bungalows and ideal testing ground for a new program under development with the Center for Neighborhood Technology (CNT) in cooperation with Community Investment Corporation.
Based on a database of actual energy use for the 1.2 million single-family homes in Cook Country, CNT Energy is developing a website where home owners can find out their home's energy score and rank it against comparable homes. The website will make retrofit recommendations tailored to the specific home, and provide connections to qualified contractors to do the work. Further supporting the value of retrofits, the database will ultimately enable the retrofits to measure in the real estate market. With an average project cost of $8,600, early results coming in from the bungalow retrofit program suggest 60 percent of bungalows are showing a reduction in utility bills of more than 25 percent.
Another CNT program, Energy Savers, serves owners of multi-family rental buildings. Steve Thomas of Genesis Group, an owner of several low-income rental properties, is retrofitting three buildings with Energy Savers. "It's been very enlightening, very helpful," he says of the energy audit CNT conducted on each building, and the report they provided identifying the buildings' inefficiencies, making recommendations for retrofitting, and quantifying savings and payback periods.
Retrofits Thomas is making include sealing floor to wall joints, insulating roofs, wrapping pipes, and changing common area light bulbs. "Some of its common sense and little things," he says, but he's impressed at the difference attention to detail can make. "It might cost you a little more up front, but over the life of the project you'll see the savings, and those are savings that I can pass on to my tenants." With an average expenditure of $59,000, retrofits under the program are typically averaging 28 percent, which, for a typical 24-unit building, is reducing annual operating costs by $8,000 to $10,000.
CNT not only develops initiatives to help citizens and communities reduce energy use, it also has its own house in order, with a LEED Platinum renovation of its 1920s headquarters reaping energy savings of 40 percent. One of the primary goals of CNT's own retrofit was to achieve Platinum certification on a conventional budget. It succeeded through the creative use of "state of the shelf" technology and a focus on the energy efficiency basics: tight envelope, high insulation levels, and high efficiency systems.
CNT is also committed to ongoing improvement. "Measure and improve is a theme through all our building energy work," says Rachel Scheu, CNT Energy's Green Building Research Coordinator (CNT Energy is a division of the Center for Neighborhood Technology). "Go do it," says Scheu, "but then measure your success so that you know what you've done correctly." CNT's energy monitoring tells them that performance varies with changes in occupancy and use in the years since the initial retrofit, heating and cooling costs have stayed constant, but a significant increase in building occupants has increased plug and lighting loads. For ongoing conservation efforts, this information validates the renovation, and focuses attention on behavioral and operational improvements.
It might be expected that the older the building, the greater the potential for energy savings through green retrofitting would be. In fact, a study by the US Department of Energy tracks building energy use increasing over the course of the twentieth century from 80,000 Bitus per square foot in buildings built before 1920, to 100,000 Btus in the 1980s. Older buildings have inherent efficiencies with high mass and smaller windows - and some have already been retrofitted. Environmental Systems Design (ESD), and engineering firm with a record of green innovation in Chicago as well as internationally, is the environmental controls consultant on the retrofit of two Mies van der Rohe buildings in downtown Chicago; the Dirksen Federal Building, completed in 1964; and 330 North Wabash, completed in 1973. "There are thousands of buildings like this across the US," says Andrew Silverstein, vice-president of ESD's commercial and international projects group. "Air conditioning hit its stride at the same time as all-glass transparent facades."
Retrofitting a building of this scale consists of a series of compromises as the design team balances energy performances with a plethora of competing priorities. "If you can think of all the complications on a project," says Brett Taylor at SOM, architects for the Dirksen retrofit, "we have them on that building." Asbestos remediation, historic preservation standards, maintenance of high security levels and, most of all, conducting work in and around the occupants of an operating courthouse energy conservation is one priority among many.
The lighting upgrade, for example, is constrained by a historic pattern of luminaires embedded in a unique plaster celling. Without the ability to change lighting density, the design team's solution is to reduce the output of the fixtures. The result is a higher wattage per square foot than would be typical today, says Taylor, but it's better than it was.
HVAC upgrades must work around tenant operations and vacancies. Upgrading the entire HVAC system is not an option for a tenanted building. Instead, inefficient perimeter induction units are being replaced floor-by-floor with a quieter and more efficient version of the same technology. Replacement of the energy-profligate all-glass facade is simply not in the budget.
The base building retrofit of 330 North Wabash, a 52-story, 1.5 million-square -foot mixed-use building, has achieved Silver certification under LEED for Existing Buildings - Operations and Management ENERGY STAR certification, and BOMA 360 Performance designation. For the building's owner, Prime Group Realty Trust (PGRT), achieving these certifications is "a great way to see all you actually do all in one place," according to Susan Hammer, general manager at PGRT. "By doing that, we're able to market our management skills to prospective tenants and to existing tenants as well. IT really helps show the marketplace that you're doing a great job."
Energy conservation measures for the building include a green roof, lighting efficiency upgrades, floor-by-floor HVAC upgrades, and rush-hour shuttle service to and from Chicago's commuter rail stations. As part of the building's sustainability strategy, PGRT facilitates the efforts of tenants to green their operations. To date three tenants, DeStefano Partners, architects for the base building renovation; Perkins + Will; and Thornton Tomasetti have certified under LEED CI. "The building makes it very easy to lead by example," says Beth Murphy, AIA, architect of DeStefano's office fit-out.
The greening and modernization plan for another Chicago icon, the Willis Tower, includes replacement of the building facade with insulated glass, a mechanical upgrade to realize savings from the improved façade, building-wide lighting controls, an elevator upgrade, upgraded boilers and chillers, and renewable energy generators. The plan, to be implemented over a ten-to fifteen-year period, projects Willis Tower's base building energy use to be reduced by 80 percent, which inspired the project team to make a leap of scale, "If we did that with the Willis Tower," says Gail Borthwick, AIA senior architect at Adrian Smith + Gordon Gill Architecture (AS+GG), "we could do it with the 550 other buildings in the Loop."
The Loop, Chicago's central core, accounts for 1 percent of its greenhouse gas emissions. AS+GG approached the city with a proposal to develop a holistic decarbonization plan for the Loop to support Chicago's climate action goals. The project team began with a survey of the existing buildings in the Loop to assess their age, use, condition, and energy consumption. The team soon realized that even if 50 percent of buildings in the Loop underwent a major retrofit, the carbon savings would still fall short of 2020 goals.
"Buildings alone weren't going to do it," says Borthwick. And so the team began to look for synergies in other urban sectors to compound the carbon savings from retrofits.
The result, the Chicago Central Area DeCarbonization Plan, is a fully integrated proposal comprising eight key strategies. The first strategy, Buildings, prioritizes retrofitting over new construction, and looks at how upgrading existing buildings can improve their energy efficiency, increase their value, and even return excess energy to the grid. Another strategy, Urban Matrix, seeks energy savings by increasing the resident density of the Loop with increased amenities, schools and services, and additional residences from converted office stock. Other strategies include Smart Infrastructure, which considers how energy can be generated, stored, distributed and shared; Mobility, which involves an assessment of transit and connectivity; and Water, Waste, Community Engagement and Energy complete the group.
Specific concepts and proposals in the DeCarbonization Plan include finishing and linking a below-grade intermodal axis across the width of the loop; adapting the Loop's underground tunnels to provide a pneumatic waste disposal system; extending existing pedestrian and bicycle paths; and publishing The Green City, a textbook that would enter school curricula as a primer on urban design and decarbonization, just as a school text accompanied the Plan of Chicago in 1911-1927.
The DeCarbonization Plan has been well received. The challenge now is implementation. "It feels like one of those wooden puzzles with the piece that holds it all together missing," says Borthwick. "That's the funding peg."
Funding is a significant barrier to retrofits at all levels of scale. The commercial retrofit market, according to a recent study from Pike Research is small compared to its potential. An owner may be convinced of a retrofit's merits but, as Silverstein at ESD observes, "nobody has any money right now who didn't already have it two years ago." Says Borthwick at AS+GG, "building owners are looking for a return on investment in two to four years. For a major retrofit, it's going to take longer than that."
Over his twelve years with DNR Windows, Tom McElherne has talked to a lot of homeowners. In his experience, a few are weatherizing to achieve energy savings, but "most of the time it's because people are very uncomfortable in their house." Residential energy retrofitting programs have achieved market penetration of less than 1 percent of eligible buildings, confirms Lee Deuben of the Chicago Metropolitan Agency for Planning (CMAP).
CMAP has identified three key barriers to the retrofitting boom: access to information, access to finance, and access to skilled workforce. "There are a lot of moving pieces," says Deuben, "a lot of barriers to information that make it hard to navigate." To address this, CMAP has received a $25 million grant from the US Department of Energy to facilitate green retrofitting's transition from an emerging, fragmented market to a fully functioning economic sector capable of achieving the retrofit rates Chicago's energy and emissions objectives need.
Over the next three years, CMAP's Chicago Region Retrofit Ramp-up (CR3) will be working with communications and public relations firms to develop a comprehensive information system to educate building owners on their options, facilitate their decisions, and connect them with the retrofit services they select. The program will be working with financial institutions to develop innovative and accessible financial products to facilitate retrofitting across income levels and building types. And it will be working with work force training organizations, such as universities, colleges and work force boards, to develop a qualified, skilled work force to fill retrofit jobs. Says Deuben, "the real intent of the program is market transformation."