Volume 49, Issue 7 - July 2014


One Lite at a Time
Glass Retrofit Options Begin to See Increasing Interest
by Megan Headley

The Numbers: Empire State Building Window Retrofit
• On-site processing of the Empire State Building’s 6,514 windows provided cost savings of more than $15 million over the purchase and installation of similarly efficient new windows.

• Through reductions in use of air conditioning and heating, the windows should provide CO2 emissions savings of 105,000 metric tons in the next 15 years.

• Installation and manufacturing savings: $14.95 million

• Estimated annual energy savings: $410,000 Source: Natural Resource Defense Council

Of commercial buildings in the U.S. still had single-pane glass in 2011.

Deep retrofits can make good business sense for building owners wanting to reduce the cost of utilities dramatically. And, while the upfront cost of reglazing can be a deterrent, some experts say it’s a lack of education that is keeping more building owners from requesting your glazing services.

Others say it’s the fact that there are newer, cheaper and less disruptive options available competing for this business.

Interest Is Out There
Overall, retrofits are on the uptick.

“We are definitely seeing an uptick in inquiries regarding façade renovation,” says Mic Patterson, vice president of strategic development with the Enclos Advanced Technology Studio in Los Angeles. “The early generation curtainwalls are now approaching 50 years old and older, and they were not particularly high performers to begin with.”

“We are actually seeing a lot more people doing these,” agrees Victor Olgyay, a principal with Rocky Mountain Institute in Colorado. “In the last six years or so we really started to double-down on existing buildings and trying to demonstrate the amount of energy savings that is available in existing buildings.”

Steve Champlin, president of Therm-o-lite Inc. in South Bend, Ind., has seen his supplemental interior window system earn increased interest in the last year. “This winter really woke people up,” he says.

January 2014 saw historic freezes in many parts of the country. Champlin recalled one Chicago building manager in particular who had been saying no to a window upgrade for years suddenly asking to install samples. “It’s an older building, built in the 1960s, with single pane glass and a lot of air infiltration at the openings. His systems were running 24 hours a day every day during the winter, and they really couldn’t keep up so a lot of pipes froze. This was the first time he had seen anything like this and he had been there for 26 years in Chicago,” Champlin says.

On the other hand, building owners who are already in touch with the sustainability movement see window upgrades as a next logical step. As Champlin points out, “A lot of building owners have already gone after the low- hanging fruit and now they’re looking at the more significant, substantial projects. Window retrofits are very effective and very cost-effective.”

It’s difficult to argue with the numbers when comparing the utility savings seen with today’s windows versus those of 20 or more years ago “When owners and tenants replace older, less energy-efficient window systems with today’s energy-efficient windows, building and unit values increase significantly and monthly energy bills go way down,” agrees Bill Jones, Eastern regional sales manager for EFCO Corp. in Monett, Mo.

By way of example, Jones cites a recent coastal condominium retrofit where his company supplied all of the doors and windows. “The homeowner’s association president told us their tenants’ monthly energy bills went down significantly and the average unit value increased by more than $10,000 each within 90 days of completion. Regardless of building or project type, energy efficiency, cost savings and increased property value are a real impetus for change.”

Patterson, however, says that few building owners pursue the performance benefits of these windows. “What has driven the majority of façade retrofits to date is aesthetics, not performance; performance has yet to emerge as a prominent driver,” he says. “Building owners are interested in modernizing building appearance, often as part of a renovation program with the intent of bumping the building from a Class B or C to a Class A, with the goal of higher lease and occupancy rates. So they do a little research and consider the scope and cost of a façade retrofit, and often decide to exclude the façade from the renovation program, instead pursuing the low-hanging fruit, like new HVAC and mechanical systems, lighting and control systems.”

As the corporate push for sustainable buildings continues, and energy-efficient solutions become more affordable, building owners are increasingly looking to reach out to new solutions. Those made aware of the benefits to upgrading glass will have two options for pursuing these savings: a deep retrofit or secondary glazing.

Holistic Retrofits
A new guide on the topic from the American Institute of Architects and Rocky Mountain Institute (RMI), Deep Energy Retrofits: An Emerging Opportunity, explains that “planned roof, window and other major envelope replacements provide opportunities for significant improvements in daylighting and efficiency at minor incremental costs, providing the leverage for a deep retrofit that reduces loads and potentially the cost of replacing major equipment such as HVAC and lighting.”

“Deep energy retrofitting of the existing building stock, including the façade systems, is the most effective strategy to transform the problematic energy and carbon performance of the commercial building sector,” Patterson says. He adds, “There are significant barriers to the adoption of this strategy, however, including cost, disruption, risk and the split incentive conflict resulting from the owner paying renovation costs but the reduced energy savings going to the tenants. A strategy of appropriate incentives to motivate building owners to undertake deep energy retrofits combined with the implementation of more aggressive building code requirements could significantly accelerate the conversion of existing buildings.”

In many cases, building owners see the most benefit of a full glass retrofit when they are already seeking to replace their HVAC system.

That was the case with the well-publicized 2009 retrofit of the Empire State Building’s windows.

“It’s a lot about timing, especially when we’re making those large capital incentives,” Olgyay agrees. “One reason the Empire State Building worked out so well from a financial perspective is that if you took the windows as a separate item from the building, they had an [approximately] 17-year payback. Because it was being done in conjunction with various other improvements to the building … we reduced the cooling loads enough to then downsize the investment in the central cooling equipment. We avoided $17 million or so in capital cooling costs and that essentially paid for the windows.”

Champlin has seen this scenario play out time and again. “On buildings that are 30 or more years old, it might be time for a heating or air conditioning upgrade. For large facilities, many times [widow upgrades] are used to reduce the total demand on the building. So if there’s a 2,000 ton chiller [used now], they may instead put in a 1,500 ton chiller and the savings between the two would more than pay for a window retrofit,” Champlin says.

While this holistic approach to building retrofits can save money for building owners in the long run, it’s a new way for glazing contractors to make money since these building overhauls are likely to use premium products.

Olgyay says that timing is the key incentive for these full glass retrofits. “Time it right so [the owner is] not just paying for reglazing your whole building but also doing blast mitigation or other things that have to be done. If the building has to be resealed for some other reason or the curtainwall is at the end of life, then it makes a lot more sense to get the deep energy retrofit benefits,” he says.

Of course, few glazing contractors are likely privy to information about when owners of older buildings are ready to upgrade their HVAC. However it is the job of building energy modeling firms to know exactly this and glazing contractors looking to specialize in retrofits can become valuable resources for these firms.

“We work with several,” Champlin says.

Building modeling pinpoints where a building is losing the most energy and where upgrades can be most beneficial. According to Champlin, prices for these services are going down as more companies are offering these simulations, and more building owners are making use of them.

“You can easily swap in different window types,” Champlin explains. Building owners can see their existing windows as a baseline then calculate the cost savings of new windows provided by your company to demonstrate how they can change energy consumption.

“A lot of building owners have already gone after the low-hanging fruit and now they’re looking at the more significant, substantial projects.”
—Steve Champlin, Therm-o-Lite

Secondary Glazing
Other solutions have emerged for when the disruption of removal isn’t an option or when existing anchors can’t support the load of today’s new products. Secondary glazing is becoming an increasingly popular way to upgrade windows and curtainwall alike.

“Other options, beside replacement, involve some form of over-clad strategy: adding a new skin atop the old one,” Patterson says. “This can provide an excellent solution depending upon a number of often complex and interrelated variables, and holds the potential to reuse at least some of the existing materials. One form of over-clad is to add an outboard skin, actually creating a double-skin system with a cavity between the two skins that can act as an environmental buffer to the interior, or even be integrated into the building HVAC system.”

When it comes to windows, rather than curtainwall, another picture emerges.

Champlin is the first to admit that when he came into the business of secondary glazing, “I was very skeptical of what I heard … I thought, ‘[Energy savings] from a storm window?’”

Not exactly.

“Usually you’re installing a window on the interior of the existing window,” explains Vincent Grieco, New York regional sales manager for Crystal Window & Door Systems in Flushing, N.Y. “That [new] window can be single- or double-glazed and it offers thermal efficiency as well as noise, dust or soot control.” Crystal has supplied its products for this application in historic buildings. “They’ll use an actual vinyl window and because the building is historic you have to line up the window with the existing profiles to match the frame,” Grieco says.

“For buildings where [the owners] like the exterior design or for historic buildings where they really can’t change the look of the building or if it’s a high-rise where they don’t want to mess with taking glass out and maybe having it pop out—there’s a lot of reasons why interior windows work. We can build a frame on the inside and put a window system on the inside to make it look new from the inside,” Champlin says.

Grieco says historic buildings are the biggest market for this technology. “A lot of these historic or pre-war buildings are built with solid walls where you have 18-inch-deep jambs. You can put in a full 3 ¼-inch window and sit it on the interior without touching the exterior window. It’s quick, you don’t need an engineer, all you need to do is match up the sight lines. It’s pretty straightforward,” he says.

In many cases, this might be the simplest sell for a window upgrade, but not necessarily one the window replacement company is eager to promote.

“I think the glazing industry is geared against interior retrofits,” Champlin says.

And why not? After all, Champlin promotes the ease of his product to building owners as something that they can install themselves to significantly improve a window U-value for the fraction of a full replacement. But it’s an option that is gaining some traction and that glazing contractors will need to become familiar with as a competitive product.

Champlin explains the product’s benefits: “In an existing building, we won’t disrupt tenants, they don’t have to move. We can be in and out in under an hour, where in other cases you might have to relocate the person from the office and they rip out the whole window and you have to do it during certain times of the year.”

It’s Coming
Both approaches have merit. Unfortunately, both also have drawbacks.

And as Patterson points out, the sustainability of going in and retrofitting dated curtainwall at the end of a set life cycle is a questionable practice. “Can we really afford to replace the façade systems of our urban high-rise buildings every 40 or 50 years?” he asks. “There are few options at this point; the die was cast when the façade systems were designed. But it’s worthwhile to consider how the façade systems we are designing and constructing today will adapt to the conditions of an increasingly uncertain future.”

In general, few curtainwall contractors are considering the building skin’s full life cycle

“Façade design practices typically do not anticipate and accommodate the need for a future retrofit,” Patterson suggests. “As a result, completely removing the entire façade system and replacing it with a new one is often the only viable option. This same problem holds with our current façade design practices as well. It is very possible that we continue to build problems for future generations of building owners and façade contractors.” 

More manufacturers agree new products, from anchors to frame, are being adapted for simpler retrofits. But those solutions are still generally few and far between. Explaining the full benefits of a glass upgrade, including the ease of use for future retrofits, could be a way to help ensure glass gets on the drawing board as a means for significantly improving a building owner’s bottom line.

“I think the glass industry has been underselling itself,” Olgyay says. “There’s been a huge focus on the aesthetics of glass, but glass is a critical element in the building envelope and to show that it has multiple benefits is really something that hasn’t been advertised by the industry.”

Glass companies and glazing contractors need to continue to sell the full story, encouraging architects to look beyond the product as a simple piece to be installed in a larger puzzle.

“For example, you’ve heard the stories in hospitals about people healing more quickly when they have a view out their window,” Olgyay says. “Well, that’s a great benefit to the insurance industry and the insurance industry should be encouraging that. Similarly, the window industry should be espousing those non-energy cost benefits of windows: comfort, satisfaction, employee turnover, all of those things that then allow them to get to this higher performance. It’s a little bit of a harder story to tell.”

But this multi-angled approach should prove valuable to companies seeking to expand their market share by offering retrofit services.

Jones points out that these energy efficiency upgrades “translate into cost savings, increased property values and satisfied owners and tenants.” That’s the message to be spread, and there are plenty of places to spread it.

“According to the Department of Energy’s Building Performance Database, in 2011 53 percent of the commercial buildings in the United States still had single-pane glass,” Champlin says. “That’s where the market is.”


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