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What is the Greenest Building?
The concept of the “greenest building” conjures up thoughts of new, sustainably designed buildings with huge alternative energy installations, cutting-edge mechanical and lighting systems, and expansive on-site recycling programs.
But as a new report by the Preservation Green Lab (part of the National Trust for Historic Preservation) posits, the greenest building may not be a brand-new, eco-friendly structure. In fact, it’s more likely to be an existing building that’s been repaired, brought up to code, and retrofitted with energy-efficient systems.
Tear Down or Build Up?
Whether you’re starting an adaptive reuse project or simply modernizing an older building, the process starts the same way – making sure the extensive renovation is more beneficial than just demolishing the old building and starting over from scratch. In addition to the possible financial incentive, the reuse project should offer an expected carbon footprint lower than what would be emitted from a new construction project. It should also require a smaller scope of work than erecting a new building, even though extensive remodeling is likely needed.
Sometimes the remodeling process includes bringing the building up to code first, the cost of which can vary depending on how outdated the building is. Building systems and areas you otherwise wouldn’t have touched must meet code so the project can proceed.
A planned adaptive reuse project requires a critical look at whether the building can be made suitable for your intended use without causing undue hardship.
“You have to do a little research before you dive into something like this,” explains John C. Wurzenberger, founder of Cobra Consulting, a consultancy focused on historical buildings, interior design, architecture, construction, and project management. “Look at the infrastructure. Is there historic significance to the building? If so, there are limits on what you can do to the building. Look at the structural integrity. Electrical service is a big thing because older buildings don’t have high enough capacity for today’s offices. That also goes for T1 internet lines and things like that.”
The U.S. is poised to demolish and replace 82 billion square feet of existing space between 2005 and 2030, according to estimates by the Brookings Institute, a research and policy organization. Erecting a new building in place of an old one results in greenhouse gas emissions during the construction process. When you consider the emissions generated when the original structure was built, reuse quickly begins to emerge as the more sustainable option.
In fact, in some climates it can take up to 80 years for a new, energy-efficient building to overcome the climate change impacts caused by construction, according to the Preservation Green Lab. Their researchers compared the performance of new construction vs. the reuse of existing buildings across seven building types (including two adaptive reuse projects) over a projected 75-year lifespan in Chicago, Portland, Phoenix, and Atlanta.
The study concluded that building reuse almost always yields fewer environmental impacts than new construction, though the range of savings varies from 4–44% depending on the building type before and after renovation, region, climate, and type of impact (such as climate change, human health, resource depletion, or ecosystem quality).
To read the full-length version of The Greenest Building: Quantifying the Environmental Value of Building Reuse, visit preservationnation.org.
Such environmental and financial benefits seemed like a perfect match for the Georgia Department of Corrections, which needed a new administrative campus that met its needs better than its former home in downtown Atlanta. The answer was found in nearby Forsyth, GA – specifically, the 40-acre, 17-building campus that once housed Tift College. Following Tift’s 1986 merger with Mercer University and subsequent move, the campus underwent unsympathetic renovations by the next owner and then stood vacant, slowly disintegrating until the state purchased it in 2000.
From Campus to Corrections
While many of the facilities lay in disrepair, it was clear that many were salvageable. But as the architectural firm Lord, Aeck & Sargent discovered, one structure – Wilkes Hall, the former fine arts building – needed such extensive repairs that it initially seemed as if demolition was the best bet. However, the State Historic Preservation Office strongly discouraged this plan because they felt the entire campus could be eligible for nomination to the National Register of Historic Properties, though the front circle is the only structure currently listed.
Ultimately, the firm saved Wilkes Hall by carefully making space in the budget for the extensive renovation needed, preventing the release of an estimated 145 metric tons of carbon dioxide that would have resulted from replacing Wilkes with a new building. Building new structures in place of all 17 buildings would have resulted in roughly 6,000 metric tons of CO2 emissions.
“The potential financial burden of demolishing vs. renovating was something we looked at,” says Christine Ray, project manager for Lord, Aeck & Sargent. “We did extensive reviews and came very close to considering demolition because it was going to be cost-prohibitive to do all of the repairs – it needed a lot of structural work. Through cost control and other reviews of what would need to be done to the building programmatically, we were able to demonstrate that it made sense to revive the existing structures instead.”
By nature, building reuse projects come with unforeseen challenges not found in new construction, especially if the reuse project involves an old or abandoned building like those found on the former Tift campus. The hazardous materials survey turned up lead paint, mold, and asbestos – not surprising, considering that some of the buildings dated from the 1880s and all of them sat empty for nearly a decade.
The complex multi-phase project presented the team with an ongoing series of challenges, requiring everyone to adapt to the unique limitations of each aging structure.
“Some buildings had more challenges than others given that they hadn’t been occupied for seven to eight years,” Ray explains. “Some needed fairly extensive structural remediation and intervention. On other buildings, we forced that issue – for example, Lies Hall was a dorm room originally, so it was carved up into little rooms. The end user wanted to create an open office environment, so we had to do some significant structural modifications to open up the building.”
During the project’s initial phases, the architectural team realized the campus didn’t offer enough square footage to fully meet space needs and had to rework plans. They hoped to save a swimming pool in Vinzant Hall for aquatic training exercises and community outreach, but were ultimately forced to scrap that plan in favor of large classrooms for the department’s training academy. This required a hard look at where cutbacks could be made without sacrificing function or aesthetics, Ray says.
Repurpose Materials Inside and Out
Reuse as much of the existing structure as is feasible to cut both costs and waste. For example, mechanical systems nearly always require replacement, but sometimes ductwork is salvageable, Wurzenberger says. Ductwork fabrication requires a fairly small amount of energy relative to more energy-intensive products, but the greener (and less labor-intensive) choice is to salvage all that you realistically can.
Utilizing a reuse and renovation strategy offers an immediate carbon savings, according to the Preservation Green Lab study, and adding energy upgrades offers the greatest emissions reduction over time. Material choice is a major factor in ensuring savings. Though the study did not evaluate building materials, it was clear that the materials-intensive reuse scenarios tested (an elementary school with a new addition and two warehouse conversions) showed significantly fewer benefits. Most startlingly, a warehouse-to-multifamily conversion offered fewer savings than a comparable new building.
“Great care is needed during the design process to minimize unnecessary additions to a building footprint through strategic space planning and the selection of appropriate materials that result in fewer environmental impacts,” the study notes.
Capitalize on the design of the existing building to identify opportunities for cost savings, Wurzenberger recommends. Look beyond what needs repair to find places where small fixes can result in large savings.
“Older buildings typically have a lot of windows, so you can put in less lighting and take advantage of the daylight. That’s a potential cost savings and a way to look at the building from a green standpoint,” Wurzenberger explains. “You can replace single-pane steel windows with new ones that look similar from the outside but have double-paned glass.”
The benefits of reuse don’t stop at the building’s exterior and structural components. Older buildings can be goldmines for cosmetic items, such as vintage trim, moldings, doors, windows, stone surfaces, stair railings, and iron ornamentation, allowing you to preserve the building’s appearance without sacrificing performance.
“I once worked on an old bank building with big round vault doors about a foot thick,” Wurzenberger says of a bank-to-multifamily renovation. “We wanted to use that door as the entry to give you the feeling of going into a bank vault, but it was cost-prohibitive to move it, so it became a feature of a common area for apartments.”
Pursue Incentives to Keep Costs in Check
In urban areas, the study notes, the pressures of achieving economies of scale and height for views and higher rents create an incentive to maximize the use potential of each site. This often involves adding floor space or viewing sites as developable land rather than buildings with retrofit potential.
In addition, developers shy away from surprises that can pop up once rehabilitation is underway, even in instances where a rehab project is the most profitable choice, the study authors write. Consider all avenues to determine the true costs of demolition vs. renovation, including financial strategies that can overcome any roadblocks to building reuse benefits. You can defray costs and shorten your payback period with help from additional funding sources.
For example, if your company is considering modernizing a vacant building, some municipalities might chip in utility upgrades or waive property taxes for a set length of time. The city of Forsyth donated water and electrical infrastructure improvements to attract the Department of Corrections to the Tift campus. This was combined with $46 million in funding from the Georgia State Legislature to create a modernized campus valued at an estimated $60 million.
Properties that will earn green certifications or are fitted with sustainable technologies, such as alternative energy sources or ENERGY STAR-rated equipment, may qualify for rebates or other assistance from local utilities. Visit dsireusa.org to find incentives in your area.
As Wise acknowledges, it’s true that an extensive renovation doesn’t afford the same unlimited possibilities as a new building where you can start from scratch. It does, however, give a dated building new life, keep costs and emissions low, and prevent your company’s carbon footprint from growing.
“The energy needed to demolish a building, cart it away to the dump, and then build a brand-new building doesn’t seem to be practical in the sense of preserving energy,” Wise says. “It’s easier to reinvest in spent energy and where needed make improvements to save energy. Most energy is lost through the roof, so a simple case might just need more insulation in the attic. Do a cost-benefit analysis, but don’t get swayed by thinking what’s new is always better.”
Janelle Penny (email@example.com) is associate editor of BUILDINGS.