This Old Thing?

Recreating the craftsmanship of the past is always a challenge for remodelers with clients who want to preserve the traditional feel of an older home. Windows are an especially tricky area. The look of historic windows can be critical to the character of an older home, but preserving or replicating that look isn't easy.

The problem, contractors say, is that it's often hard to get newer manufactured windows to look right on an older house.

These windows were designed to match a historical double-hung profile, and, the manufacturer claims, outperform the original. Some contractors say that improved performance negates the challenges of finding components that are truly historically accurate.

Photo Credit: Anderson Windows

“One of the things that typically falls apart when you're trying to replicate a historic window is the dimensions,” says Michael Klement, president of Architectural Resource in Ann Arbor, Mich. “The face dimension, stiles and rails, the window sash, vertical or horizontal components — historically, they were larger than what they're doing now.” Jamb liners are troublesome as well, Klement says, because newer liners are often made from vinyl or some other synthetic, rather than from traditional wood.

“We have to be realistic when we say ‘match that look',” Klement says. “We're going to do a lot in terms of scale, proportion, sight lines, etc., but it will not be exact.”

Another challenge, Klement says, arises from the fact that today's wood windows are usually made of pine. “Typically with a Craftsman house, you want to go with a stained look, which is tricky with pine: It's not going to stain out to match,” he says. “We're just very careful with the staining. It takes patience and sometimes a couple of tries to get it right.”

In recent years, however, manufacturers have made a greater effort to create products that match historical profiles. For example, most manufacturers offer simulated divider lites — cosmetic grilles that are surface-applied to the glass, with spacer bars between the panes. “The intent is to give it the look of a historical window but with an uninterrupted pane of glass,” Klement says.

It's also possible to give a newer unit a more traditional look by dressing it up with custom trim. Klement recalls a remodel of an Italianate house that had a large arch-top double-hung. A custom-manufactured window “wasn't in the budget,” he says. “So we used exterior trim to create the look of the arch without actually [fabricating an arch-top window]. You have to be creative in how you approach these things.”

Keith Alward, president of Alward Construction in Berkeley, Calif., says he often has to build a thicker sill when installing manufacturers' windows. “A typical commercial window usually doesn't come with much of a sill,” he says, “so you might want to put in a nice sill that matches the house and let it sit on that. From a distance it will look like the original, even though it's a modern window.”

THE EFFICIENCY TEST

Despite the aesthetic challenges, replacement is an obvious and attractive choice, especially given the growing demand for better energy efficiency. Classic single-pane, double-hung windows, after all, were not designed with building science in mind. Today's double- and triple-glazed windows, on the other hand, cut down on heat loss in winter by providing insulating airspace. And low-E coatings reduce solar heat gain in the summer.

Tax credits of up to 10% of purchase price for Energy Star-rated windows make replacement even more attractive. Klement, the Ann Arbor remodeler, often works on pre-World War II homes and has won awards for designs that adhere closely to traditional architectural styles. Still, he rarely prescribes anything but replacement. “

A huge focus of our practice these days is energy efficiency and sustainability,” Klement says. “These [historic] windows have done their job and performed well in the environmental and energy-efficiency framework that existed when [these structures] were built, but where we are right now in terms of technology is so far ahead of that. Unless you're doing a house that's on the historic registry or in a historic district, I think it doesn't make any sense [to repair windows rather than replace them].”

REPAIR AND RESTORATION

But a number of contractors argue that repair and restoration should be given more consideration. Energy efficiency, these contractors argue, should not be given such great weight because windows only contribute about 20% to 30% of heat transfer. Compared with modifications that improve insulation and reduce airflow, no window improvement will have as great an impact on the overall energy efficiency of a house, particularly an older house that loses heat in a number of other ways.

“For example,” Alward says, “a single pane of glass is rated as R-1; a typical stud wall” — a cavity wall with insulation, framing, and an exterior and interior — “is probably an R-13. If you go to dual glazing, you've increased it to about R-2.4; you've hardly done anything. It's an overrated energy-conservation technique.”

In fact, research has shown that weatherizing, reducing airflow, and installing low-E storm windows can be just as effective as replacing a single pane with a double-pane low-E window. Research by the Oak Ridge National Laboratory found a negligible difference between energy savings produced by these two options. A study by the city of Boulder, Colo., found the same result, concluding that “replacing a historic window does not necessarily result in greater energy savings than upgrading the window.”

Robert Cagnetta, president of Heritage Restoration in Providence, R.I., says that although repairing old windows and installing storms may cost more up-front, it is more cost-effective in the long run. “If you put in a storm window for, say, $200, you'll have to replace that storm window every 20 to 30 years, but you won't have to replace the unit, the window itself. If the replacement window fails every 20 to 30 years, you're replacing the entire thing.”

Window restoration can be costly and time-consuming, but some contractors argue that the results (above, left) are worth the effort when compared to low-cost replacements (above, right) that are installed with no regard for aesthetic or historical accuracy.

Photo Credit: Anderson Windows

Cagnetta argues further that homeowners and contractors who think replacing older windows is a green improvement aren't looking at the big picture; for one thing, replacement creates a lot of waste. And, he adds, “People aren't looking at life-cycle costs. You have to think about how much energy it took to manufacture the window, to mine the raw materials, to transport the windows from the factory to the supplier and from the supplier to the jobsite. What's your net energy consumption to do all that?”

Perhaps more important, restoration proponents say, is that historic windows are superior to their newer counterparts in terms of quality as well as aesthetics.

Dixon Kerr, a window restoration specialist in Richmond, Va., argues that there's no comparison between pre-World War II construction and what factories produce today. “The main difference is that windows used to be made out of heart pine and long-leaf pine that was several hundred years old when it was harvested; the wood was very strong. Manufacturers today use wood that's not nearly as old and it's not as strong,” Kerr says. “The craftsmanship was much better, too. You had true mortises and tenons, really quality woodworking.”

Once properly repaired, experts say, historic windows can outlast new manufacturers' offerings by decades. Repair and restoration, however, can be a time-consuming and laborious process. For Kerr, who typically works with wood double-hungs, the effort requires a commitment to often-tedious woodworking.

“I strip all the paint off, take all the old glass off, redo it completely, make any repairs I need to do, prime it, glaze it, glaze it again,” Kerr says, outlining the process. “It can take three to four days on a window, depending on the window.”

Alward, the Berkeley remodeler, often works in homes built during the first decades of the 20th century. He says that though he will spec new manufactured windows, he prefers to replicate historical windows exactly, typically at a local sash and frame shop.

The cost, he says, is not prohibitive given that such a job would call for something more expensive than the cheapest replacements anyway.

“You can have a shop make a 2-by-3-foot double-hung out of good material using typical standard parts and profiles,” Alward says. “A window like that's going to cost $300 or $400.” The same window by a brand-name manufacturer costs close to that as well, he points out.

Most important to getting the desired result, Alward says, is clear communication and oversight.

Alward and Kerr also often turn to the large recycled and salvaged parts market for hardware, components, or even whole window units. Salvaged parts tend to require additional cleaning, touching up, or repair before they can be incorporated into a restored or replicated window, and the salvage market is often difficult to navigate.

Factoring in all that time and effort, recycled parts aren't likely to produce any net savings. But, Alward notes, price and convenience can't always take precedence. “If it's really important, you'll do it and the client will pay for it.”

—David Zuckerman writes frequently on construction topics from his home in Brooklyn, N.Y.