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  • It's A Steel

    Steel windows present a challenge in many restoration projects. By Martha McDonald When restoring historic buildings, the question of what to do with the existing steel windows is often a serious concern. Architects may want to turn to replacement windows for energy conservation reasons, and there are firms that can provide historically accurate new windows. On the repair side of the argument is John Seekircher, owner and founder of Seekircher Steel Window Repair, Peekskill, NY. The firm repairs and restores thousands of steel windows every year, for commercial and residential projects. The family-owned and operated firm has been in business since 1977, and has a long list of projects to its credit, including Frank Lloyd Wright's Fallingwater. One of the advantages of repair versus replacement, Seekircher notes, is that it is usually quite a bit less expensive, "and the craftsmanship and lifespan of historic and steel windows is really unmatched by most replacement windows on the market today. Once restored, the historic windows are as good as new, even better." One such recent example is Ely Hall at Vassar College, Poughkeepsie, NY, where Seekircher restored 24 steel windows of various sizes ranging from 4x5-ft. to 7x11-ft. "Here at Vassar College, we make a great attempt to restore our historic building envelope systems," says Jeff Horst, Director of Special Projects at the college. "Many of our buildings are older so that involves masonry restoration, replacing roofs, and either refurbishing or replacing the windows. One of the considerations is improving energy efficiency. Ely Hall has a mix of window sizes, some with divided lites, and some with no divided lites." "The work is the same in all of the jobs," says Seekircher. "The windows are primed by hand, (we don't spray paint) and putty-glazed by hand, the same way it was done years ago. Then we add two finish coats and clean the glass and you have windows that are as good as new. The alloys in those windows are incredible. At Vassar, we only replaced about six feet of steel. The windows were still in very good shape. That's what we come across generally." "The task was to restore the envelope system, the copper roof and the masonry," Horst notes. "The windows – both wood and steel – were a bit of a challenge. There was no question about the wood windows – they had to be replaced. At first we decided to replace the steel windows, but after further investigation, we found that the steel was in good condition; the paint and the glass were not." "Seekircher made it clear that these windows were certainly worthy of restoration. He told us that the steel from this era is very good. We saw very little rust," says Horst. "The bottom line is that Seekircher completely restored the windows, with paint the same color as the original. We have gotten many compliments on the windows. They look really good, just like the original windows." The college brought in CVM Engineering, a Philadelphia building restoration consultant for the project. "Vassar is one of the older campuses in the country and they have a lot of historical buildings," notes Matt Ridgway, architectural engineer, CVM. "Ely Hall is not on the National Landmark list, but it was built in 1889, with an addition in 1906. Our understanding is that the windows were original to the building." "Our preference is always to salvage historic fabric in these historic buildings," he adds, "but one of the big questions is energy efficiency. What are you sacrificing energy-wise with restoration?" CVM looked at different options, including new thermally-broken aluminum windows that would replicate steel, and offer increased insulation values. He found that the cost of replication was two to four times the cost of restoring the historic steel windows. A decision was made to use laminated glass, rather than single-page glass, to provide more energy efficiency. "The steel windows at Ely Hall were in fair condition, needing only to be scraped down, primed and painted," he notes. "So we restored them all in place. Fortunately, Seekircher also had a collection of historic hardware for replacements where needed." "When looking at historic windows, there is always that decision to see if something is worth salvaging from financial standpoint and how important is original fabric. This project married these two thoughts. When we can, we like to try to get the best of both worlds." While the windows at Vassar were restored on site, those at Columbia University Hospital in New York City were removed from the building and restored in the Seekircher shop. Another difference was the pricing structure – it was more expensive to restore rather than replace the windows, but the decision was made to restore because of the significance of the historic material. "The Physicians and Surgeons Building is the flagship building for Columbia University Medical Center, and is the main entrance to the center," says Richard H. MacDowell, CSI, CDT, partner, Grenadier Corp., Bronx, NY, the general contractor for the project. "It is also one of the earliest buildings, constructed in the mid-1920s. The three monumental windows are right in the front. They are enormous – three stories high." Richard Pieper, director of preservation at Jan Hird Pokorny Associates, NYC, the architect for the Columbia University Medical Center project, notes: "We are a preservation firm, so we are very, very sensitive to changes in design. In this case, we felt very strongly that aluminum extrusion windows would significantly impact the look of the building. We spoke to the client about it and they agreed." "These are definitely the biggest steel windows we have worked on," says Seekircher. "It was a challenge taking them apart. When they are this big, it is usually easier to work in place, but because they had to do some repairs on the limestone, we would have been in the way, so the work was done in the shop." The windows were dismantled, loaded into Grenadier trucks and taken to the shop. "We made several trips to the shop to monitor the work and talk about certain repairs," MacDowell notes. "At some point, a decision was made to replace all of the glass rather than just broken planes." Grenadier workmen set the repaired steel windows in place and then Seekircher did the final painting and glazing (1/4-in. laminated glass) on site. "The client was thrilled," says MacDowell. "We got so many comments from people who said they were such beautiful windows. They didn't realize that they were the old windows. Even some engineers thought they looked like new windows. John also added some new hardware. The windows really stood out. It was a big 'wow' factor." TB

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  • Preservation and Sustainability

    The restoration of historic buildings in Charleston, SC, shows how sustainability and preservation issues can be solved. By Ralph C. Muldrow, RA Historic Charleston, SC, has weathered more than its share of traumas since its founding in 1670. The city has survived numerous fires, frequent hurricanes, bombardments, a major earthquake and a hot, humid climate. Like many southern cities, Charleston experienced burgeoning growth in the post-World War II era, not only because of the Naval Yard as an employer but also, importantly, because of the new availability of air conditioning that facilitated growth throughout the South, although at the price of increased energy use. All along the way, Charleston's ethos has been intertwined with the veneration of the past, especially the architecture. The seal of the city has a Latin phrase that translates, "She guards her buildings, manners and laws." Charleston created the first historic district in America in 1931, and continues to stringently guard the buildings of the old and historic district. Protecting the historic buildings is a sustainable practice, utilizing the 'embodied energy' that it took in terms of materials and labor to build and maintain this sought-after historic city. Of course, the buildings do present a range of styles, but the pervasive typology is that of the single house. In the 18th and 19th centuries, the single house was the dominant typology. The plan has the narrow end facing the street with a false door which leads to a real front door half way down the side of the house. This was greatly augmented by about 1800 when the false door became the entryway to a long, often double-height side porch, called a 'piazza' in Charleston. We find this floor plan recurring from the Georgian period, through the Adam (Federal) Style, the Greek Revival Style, Victorian styles, etc., but in all of these exotic garbs the floor plan, fenestration and formality remain constant, with only a few elements giving the house a discernable 'style.' The distinct urbanism created by the repetition of the single house is a very sustainable model in and of itself. The survival of the underlying form of the single house over large areas of the city is an embedded 'sustainable' urban form. These older blocks provide a syncopated rhythm to the street, with the sustained intervals of house, piazza, garden, house, piazza, garden, etc. Post-Bellum Charleston was not a prosperous place. The local saying was, "too poor to paint, to proud to whitewash." Yet these weathered remainders of times gone by largely remained standing. Thus in the 1920s there was a phenomenon now called 'the Charleston Renaissance,' wherein the crumbled stucco and naked wood siding of the day became a tourism magnet. Spurring this movement were the evocative etchings of Elizabeth O'Neill Verner, the lyricism of "Porgy and Bess," and even the African-American derived dance, "The Charleston," with its raw energy. It was in that era that many gardens were designed for the single houses – beautiful parterres with shaped boxwoods and trellises. This glorious layer veils the truth about these back yards, which historically usually functioned as 'urban plantations,' with cows and hogs and chickens raised at the homes. This 'weathered city' utilized her unique, long-standing architectural layout of houses turned longways into their sites to create a shelter appropriate to the climate. The piazzas all face south and west, which allows them to catch prevailing breezes and allows for the shading of windows when the sun is high in the summer. And in winter the sunbeams drench the house with much needed warmth. There is a 'louver effect' in which the houses themselves provide shade to the neighboring house and/or garden, just as the louvers of a vent shade each other. The side garden also functioned as a firebreak. The formal fenestration allows for numerous windows on the south and west sides of the house (facing the prevailing breeze) which feed the few windows (mostly in the staircase) of the north-facing side, allowing for cooling breezes through the single room depth of the house. And despite earnest attempts by the government throughout Charleston's history to require the use of brick for fire resistance, many houses are wood frame, clapboarded houses built originally with no insulation to allow cooling air movement within their walls. Even the chimney stacks, which facilitate air movement, aided in cooling the single house in the summer. Case Studies For the purposes of this study, "sustainability" will be defined as an approach to construction that strives for efficiency in its use of energy, water and other resources. It is also an approach that favors occupant health and improved employee productivity, and it strives to reduce waste, pollution and environmental degradation. Green products are those that further the cause of sustainability through recycling and low environmental impacts. Even green products may cause some friction with sustainable building. For example, should one buy a 'green' adhesive product from California? Or should you instead purchase a normal adhesive locally, saving the carbon footprint associated with the transportation of the product, and promoting the economic health of the community? Should you buy the adhesive product at a national chain store like Home Depot for a slightly lower price than the locally owned building supply store, or should you pay the extra money to sustain the viability of a local company? Now add to the equation a host of preservation issues involved in a building rehabilitation project and other questions arise. The preservation approach to a significant historic building would be to save as much of the extant fabric as possible, or to agree on a period of significance to aim for in the course of making rehabilitation decisions. Which priority trumps the other? This inevitably differs from one project to the next. Preservation approaches include issues that are less quantifiable but just as important in their own right. For instance, aesthetic considerations may not be optimizing energy use but may instead be highly important for the perpetuation of a building, avoiding demolition, which negates all of the embodied energy in such a structure. The same goes for significance. For instance, a plain cinderblock structure may be an iconic talisman for the civil rights movement. Should we load up the roof with photovoltaic panels to lower the use of electricity, or will that be an unacceptable incursion on the historic structure? #93 and #97 Broad Street Some current construction projects in Charleston are grappling with marrying sustainability with preservation – two important but sometimes differing agendas for the betterment of society. A high profile case in point is the two-building project at #93 and #97 Broad Street. The first building, #93 Broad Street, was constructed ca.1800, while #97 was built in 1835. The goals for the much altered and deteriorated buildings were that they may be used as offices and that they will be historically correct and constructed sustainably with 'green' products. In addition, appropriate reconstructions should be based on historic photos (rather than expanding over every last square footage on the site). The two buildings were extremely deteriorated and had been unoccupied for many years. One example of sustainability and preservation is exemplified by the mechanical systems. Instead of one or two large condensers, #93 Broad has been fitted out with six condenser units, all with a SEER rating of '16.' They are mounted on heavy timber dunnage with rubber blocks to dampen the inevitable vibrations. A filtering system dehumidifies the sultry summer Charleston air and cleans it as well. This number of condensers allows for them all to operate at about 60 percent of their full strength so as not to wear out easily. This also allows for a number of different zones in the building that can then be adjusted as necessary for specific needs instead of cooling the entire building needlessly. Many other sustainability items have been addressed with the target being LEED Silver certification. Meeting preservation requirements as well has been a challenge. The windows, for instance, have all been repaired instead of being replaced, including matching glass panes where the original ones are missing. This painstaking work is appropriate for such prominent historic structures, and it fulfills sustainability goals concerning 'embodied energy,' respecting the reuse of the windows instead of sending them to a landfill. The original windows were made from slow-growth wood, which is much sturdier than most wood today. The sills were replaced with solid mahogany – a wood that resists decay naturally. They are connected to the jamb with mortise-and-tenon connections. Yet with all of that going for them in the preservation process, a purely sustainable approach might encourage the provision of new windows with higher R-values, to save energy. One way to meet both goals would be to apply interior storm windows. The historic brick was another issue. An important part of reusing and re-pointing historic brick is the understanding that early bricks were softer than later 19th-century machine-made bricks. Conservation practice emphasizes the need for lime-based mortar which would have been used initially, rather than the Portland cement-based mortar. The latter is harder than the soft bricks and can lead to spalling. The use of lime mortar, however, is not a 'fix all' in every case, and it carries with it a higher need for maintenance in our present day market where labor is very expensive. (The hands that built the brick walls worked for lower wages and probably included slaves). The solution was to use salvaged bricks from a ruined 19th-century addition, with equal amounts of Portland cement and lime in the sand aggregate. The use of Portland cement will significantly extend the life of the mortar with these harder, machine-made bricks. Insulation is obviously an important component of the energy-saving approach advocated by LEED. #93 Broad has a new rear addition which is a replica of the earlier addition that was a ruin. In the new addition Charleston-based Meadors Construction used spray foam insulation on the back of the roof sheathing. In the historic section, rigid insulation was used to create airspace to allow airflow through the rafter plenums. Closed-cell spray insulation was used to provide a redundant layer of waterproof material and to prevent mold. The roofing is standing-seam copper on plywood sheathing with insulation as described above. Copper has a long life expectancy and is historically accurate, but it costs significantly more than an asphalt shingled roof and comes from distant sources, possibly even from China. Sustainability precepts would recommend that materials be local or at least from within a 300-mile radius, minimizing the fossil fuel costs to transport the material. Instead the copper has a big 'carbon footprint' due to the transportation factor. However, preservation precepts call for the historically correct roofing material, and it could be argued that the copper roofing is a 'sustainable' product because of its long life. Green products used in the rehabilitation of these severely damaged historic buildings included a fire-rated water-resistant sheathing made by National Gypsum Company, the use of stainless-steel screws to strongly secure the framing in perpetuity, lumber purchased from local forests, low-flush toilets, hot water on demand (to keep from having a hot water heater going all of the time), electrical elements such as lights are on a clock or a timer, insulated ductwork and numerous others. The exterior walls are thick brick coated with true lime stucco and painted with mineral pigment paint which allows for vapor to exit the wall. In terms of the sitework, a silt fence contains run-off of pollutants from the construction site. Metal scraps were recycled and plaster was sent out to be crushed and reused. This high-profile site may serve as a model for others. Conclusion: As these case studies indicate, sustainability and preservation don't always go hand-in-hand, but knowledgeably made decisions allow us to utilize new technologies and materials to allow sustainability goals for historic structures. Perhaps a new LEED category for historic structures should be created. The Charleston single house has built-in sustainable characteristics out of necessity. We can learn from the sustainable aspects of historic buildings and we can then augment their sustainability with emerging 'green' technologies. TB  


    Ralph C. Muldrow, RA, is the Simons Chair Professor of Architecture and Preservation at the College of Charleston. He has degrees in architecture and preservation from the University of Pennsylvania and undergraduate degrees from the University of Virginia. He has worked at a number of preservation architecture firms including John Milner Associates. He teaches architectural design and architectural history and has lectured widely on architectural and preservation topics.

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