Windows Help Preserve Historic Campuses
Carefully designed windows can bring modern energy savings, while remaining true to historic campus character.
John Lewis, American Architectural Manufacturers
Despite the general downturn in construction that began in 2007, one of the comparatively healthier commercial window market segments in 2008 was the construction or renovation of educational facilities. This has been spurred by an increasing focus on the infrastructure, the availability of grant funds, and demographic trends. Specific to the fenestration industry, some window manufacturers have fared relatively well by specializing in the niche market of historic reproduction windows.
|The decision to renovate an historic structure or build new is usually more than a simple cost-benefit analysis.|
Renovate or rebuild?
The question arises when contemplating the modernization of educational facilities on a campus or in a community whether to build new or to renovate an older structure. In the case of historic buildings, the decision is often more complicated and involves more than a simple cost-benefit analysis.
Constance E. Beaumont, of the National Trust for Historic Preservation, Washington, has said, “Too many schools are casually condemned by biases that favor new construction, by school facility assessments that reflect little expertise in the rehabilitation of older buildings, and by ignorance of basic techniques for helping older buildings meet modern codes and program requirements.
“Too often, ADA [Americans with Disabilities Act], fire safety, and other important requirements are used as an excuse to demolish a valued school when in fact these requirements frequently can be met at a reasonable cost,” she continued. “Too often, smaller, community-centered schools that have held neighborhoods together for decades are destroyed without competent evaluations of their potential for continued use through modernization.”
After World War II, school construction entered a period of fine workmanship and use of quality materials, with ornamental details in stone, terra cotta, and tile that characterized the late 19th and early 20th centuries. Preservation maximizes the use of these existing materials and infrastructure, reduces waste, and preserves historic character. Even in a new-construction situation, a building’s proximity to other historically significant structures is often the driving force behind design and component selection for the new construction.
Weighing the pros and cons takes historical preservation knowledge, experience, and creativity. Few building committees, boards of regents, trustees, or school-board members have the technical expertise to properly compare the merits of renovation with those of new construction. Many of the architects and planning firms they retain to advise them can be unfamiliar with renovation techniques, or may simply be biased in favor of new construction.
All cost factors may not be adequately assessed in a cursory or biased cost-benefit comparison. For example, as much as 25% of the cost of new construction lies in preparing the site, laying the building foundation, installing utilities, and creating road-work access. Another 25% goes toward the building structure-its framing, walls, and roof. With a historic building, those components are already in place. If the historic building is planned for demolition, there will be costs to demolish it, abate hazardous materials, and dispose of debris (often 4% to 5% of the overall replacement costs).
Challenges of historic renovation
Perhaps the biggest challenge is maintaining the integrity of historic buildings while incorporating energy-saving measures and meeting accessibility and fire-code compliance mandates. These are requirements that can often conflict.
Codes: While preserving a building’s historic aesthetics often dictates all other elements of the project, it must also meet applicable building codes regarding accessibility and fire safety.
However, building codes are generally written with new construction in mind and often rule out older building materials and methods, even though the latter may result in buildings as safe as those constructed with new materials and methods. Cost-benefit studies often rigidly interpret code compliance, incorrectly declaring a building unsafe or cost prohibitive to retrofit.
In truth, the codes have some flexibility and offer the potential for waivers. Historic designation could make the project eligible for alternative building-code requirements that facilitate upgrades and open the door to additional funding sources.
The 2006 ICC International Existing Building Code (IEBC) is an alternative that contains requirements for improving and upgrading existing buildings to conserve resources and building history, while achieving appropriate levels of safety.
The Uniform Code for Building Conservation, published by the Int’l Conference of Building Officials (ICBO), Washington, allows for certain trade-offs, making it easier and less costly to preserve and renovate historic buildings without compromising safety. It allows historic restoration while accommodating life-safety upgrades (electrical and lighting systems, fire sprinklers, new fire alarms, smoke detection, and exiting), ADA-accessibility improvements, and data/telephone systems.
Individual states and municipalities may also have their own codes for the renovation or preservation of historic structures.
Architectural bias: Architects inexperienced in rehabilitation techniques sometimes overestimate the cost of bringing an older building up to code. Not all have training, experience, or an interest in the subspecialty of historic rehabilitation, and some may be unfamiliar with or biased against renovation options.
Community bias: Many people, including facilities planners, equate new buildings with better education and older buildings with inferior education, so it is easy for the new-is-better mantra to drive decision-making.
Unknown factors: Unlike most new-construction projects, historic renovations also often hold surprises. Despite extensive efforts to uncover structural anomalies or hazardous materials before renovation begins, unexpected issues can arise after the work has started.
Despite their age, some school and university buildings are better built than those of more recent vintage. Older school and university buildings can be adapted to meet today’s life safety, handicapped-accessibility, computer technology, and educational program needs. Creative architects experienced in building rehabilitation techniques can move partition walls to change the size of classrooms, install ramps and elevators to improve the accessibility of a building, and add sprinklers and exits to enhance life safety.
A look at windows
Windows, as much as any architectural feature, define a building’s character, style, and historical context. To be true to its purpose, historical restoration must therefore carefully consider the appearance of windows, along with performance requirements such as energy efficiency and ease of maintenance. Astute manufacturers have either specialized in or offered specific product lines intended for historic replication. These products can closely match vintage wood or steel windows while offering an extremely energy-efficient alternative.
Modern materials offer the structural strength needed for large window expanses and can be precision-shaped to accurately duplicate the delicate shapes and sightlines of the original windows. Rigid tubular shapes, integrated muntin systems, and profiled exterior trims and panning are particularly useful with most window types offered by manufacturers.
When the framing profiles are made deeper instead of thicker as a way to structurally accommodate thermal barriers, wind loading requirements, insulating glass, and weatherstrip channels, products can be made with historically appropriate smaller sightlines. For example, products are available that set back the glass in both fixed and operable windows, presenting a shadow effect, often popular for historic replication.
Where replication of a particular architectural design or historic style is important, windows can be specified to match, using special frame shapes (e.g., curved tops), true muntins or grids, unique trim or panning profiles, transoms, sash lugs, and finishes.
Another approach takes advantage of structural-glazing technology to bond the glass to narrow sash members. The resulting thinner exterior profile can also duplicate the characteristic putty slopes of the old-style steel casements, while accommodating muntins and artful shapes in the brickmold. Some notable examples of how advanced-design technology can be artfully and efficiently melded with historic guidelines follow.
Modern meets historic
Renovation of the Univ. of Notre Dame’s 60-yr.-old Farley Hall in South Bend, IN, called for historically styled, modern performance, durable windows to help preserve the campus’ architectural legacy.
The 517 aluminum replacement windows feature a beveled exterior face to replicate the glazing used on classic steel and wood windows, while mimicking the sightlines and look of the old sashes. The system replicates the custom extruded panning that fits the building’s recessed openings. A 3D rendering of the panning profile helped Notre Dame officials visually review and approve the design.
The beveled exterior face with beveled muntins replicates the original system’s wood and putty units. The historic grids fasten to the frame, but sit off the glass to make cleaning easy. The champagne-colored anodized finish smoothly transitions with the surrounding wood and brick.
The equal sightlines are preserved at vent and fixed locations. Structural integrity is strengthened with visible butt hinges. But most critical was the panning and achieving the right contours of the previous woodwork.
Reed College, a private liberal arts college founded in 1908 within the residential Eastmoreland neighborhood of Portland, OR, is characterized by its Tudor-Gothic style architecture. The general upgrade and restoration of the school’s administration building included the replacement of the original 200 single-glazed windows, while remaining true to the historically relevant gothic character. This included accommodating the imposing brick and granite fascia by placing dividers across the center of the middle and top story windows. The interior has original mahogany trim and hardware that had to be preserved during the renovation.
The objectives were met with pultruded fiberglass, double-hung retrofit frames with a simulated-wood interior finish, the vertical fir grain of which was easily matched with the existing trim finish.
The 928 fixed and projected window units required for the new Univ. of Maryland School of Law, Baltimore, had to meet the neo-traditional, collegiate gothic style of the adjacent historic Westminster Hall, as well as the principles of sustainable building practices.
The high-performance windows that were selected accommodated equal sightlines for fixed and projected styles with no vent overlap, and protect the library’s valued archives from water and air infiltration. Additionally, the windows’ low-E coating and high acoustical rating maintain a comfortable learning environment for students.
Engineered replacement windows for Vanderbilt Univ.’s Nashville, TN, campus matched the original steel-and-putty windows and gothic style of historic buildings while providing increased energy efficiency. Historic campus buildings include Benson Science Hall, Calhoun Hall, Jacobs Hall, and Divinity Quadrangle, which were originally built from 1859 to 1950.
Eastern Washington Univ.’s historic Showalter Hall, Cheney, WA, originally built in 1915, required that replacement windows maintain the architectural integrity of the original windows and remain operable for ventilation, in spite of their 9-ft. height. The aluminum windows were glazed with low-E insulated glass and coated with a custom ivory finish that matched the building’s existing terra cotta masonry trim.
Carnegie Mellon Univ.’s Purnell Center for Performing Arts, Pittsburgh, was a new construction project that was challenged to remain true to Carnegie’s architectural vision from the early 1900s.
For the Center’s more than 10,000 sq. ft. of windows, design flexibility was especially important. Dance studios required operational windows for natural air and, with ceilings of 15 to 18 ft., remote operators had to be installed. A custom finish, now called Carnegie Green, was developed for the exterior and a standard white was used for the windows’ interior. Window framing depths varied from 3 1/4 to 6 in., but all needed to appear as similar pieces of the whole structure.
With windows, as well as with all key components and materials, the technology and design expertise exists to preserve the best of the past while delivering the performance benefits of the present.