Kehoe Iron Works Rehabilitation
With a vision of developing a site that is “private but feels public” to showcase the performing arts, healthy living, and history, Charles Morris set out to renovate the long vacant and forgotten Kehoe Iron Works complex. Located at the northeast corner of Savannah’s National Landmark Historic District, historic preservation was at the core of the project. Involving multiple phases, design work included the stabilization and rehabilitation of four historic buildings, as well as the sensitive integration of multiple modern yet diminutive additions. A challenging and complex project, every condition and goal was addressed with fervor and creativity, transforming issues into opportunities.
Previously a vacant site and registered brownfield, at one time the Kehoe Iron Works seemed doomed for eternal neglect and abandonment. Further, its situation on an unusually sloped site atypical to Savannah proved challenging. As a result, significant engineering work accompanied the rehabilitation design, providing the necessary framework to make the client and architect vision a reality.
An L-shaped complex, the iron works was originally built in three phases to include masonry and metal structures. Suffering from significant deterioration, it was determined at project outset that the historic metal Machine Shop would be renovated first. The site’s abandonment had been the least kind to this structure, as entire sections of cladding were missing, leaving its internal organs exposed.
With several columns rusted and dangling from the truss system above, structural stabilization came first. This included splicing historic columns with new base material, restoring the building’s steel framing and truss system, and the installation of a new corrugated metal exterior. On the interior, a roughly 7,000 square foot open floor plan was preserved and a subsurface modern addition added, taking advantage of the site’s sloping topography to integrate a full-service catering kitchen. Diminutive to the Machine Shop and capped by a terrace, the addition incorporates needed facilities while preserving interior spaces and capitalizing on views of the adjacent Savannah River. Separately, an addition to house restrooms was built, attached but outside of the historic footprint, clad in salvaged corrugated metal from the Machine Shop’s original exterior.
Throughout the project, documentation and research served as the backbone of all work performed, informing the retention of historic elements whenever possible and the replication of missing elements where deemed necessary. In the teaching kitchen, insulation was added to the ceiling, covered by salvaged wood, to condition the space and preserve the exterior cornice profile.
North of the central tower, an elevator and circulatory stair were incorporated into a new addition, outside of the building’s historic footprint. Clad in zinc and glass in a contemporary design, the addition allows for the clear delineation of new versus old. Further, it is completely self-supported using steel framed to hover above and match the slope of neighboring foundry rooflines.
Rooted in preservation principles, contemporary design, and a strong vision for use of space, the Kehoe Iron Works Rehabilitation overcame significant challenges to produce an extraordinary facility, exceeding client and community expectation.
Design Challenge
With historic preservation and the performing arts at the core of the project, the conversion of the complex’s all-metal Machine Shop for use as a performing arts venue was a challenge that required significant design and engineering attention.
Rooted in a relationship with the Savannah Music Festival (SMF), both the client and the architect witnessed the festival’s challenges in recent years. With the growth of the SMF to a two-week long event housed in venues across downtown, the need for high-quality, mid-size event space as well as venues that can house multiple performances in tandem seemed to grow greater every year.
With the success of a smaller historic venue adjacent to the iron works, the owner was particularly attuned to the needs of the SMF and saw the conversion of the iron works as an opportunity to develop a performing arts complex. This, paired with the design architect’s experience in historic preservation and sound engineering specifically for the SMF, allowed for the development of a comprehensive solution to this design challenge.
At the outset of the project, it was determined that the most suitable space for events had the greatest amount of open floor space, the Machine Shop.
Understanding the importance of maintaining the space’s historic appearance, it was determined that the building would remain clad in metal on the interior and exterior. The design had to be both aesthetic and functional. As a result, a custom metal sandwich assembly meeting all technical criteria without sacrificing aesthetics was prescribed. The top layer includes a Galvanized corrugated metal exterior over a roof membrane and recovery board. Supported by new structural metal decking spanning the interior steel structure, this assembly helped create a diaphragm to meet current structural lateral loads. A five inch layer of rigid insulation over the decking brought the roof envelope into compliance with current energy codes. Although the top layers of the assembly are not unusual, the lower part is designed to replicate the historic corrugated metal appearance of the interior of the building while also providing the necessary acoustical performance qualities of modern high performance materials. The design team utilized the purlin space under the new metal deck to provide acoustic insulation and absorption materials hidden from view. The use of bagged acoustic insulation popular in recording studio design in various thicknesses set against perforated corrugated metal panels created a historically accurate yet controlled acoustical environment necessary for performance spaces. The correct formula to calculate the size of the perforations in the metal was paramount to its success.
Other design accommodations are reflected in the use of custom built perforated metal screen partition walls with fabric interiors, lights with the ability to change hue and color, and a Crestron system for full control of lighting and sound.
What may have seemed an impossible task, the historic metal Machine Shop building was transformed into a performance space in a way that honors its historic integrity while also providing performance quality sound engineering atypical to metal construction.Physical Context
The Kehoe Iron Works location and surrounding topography had a significant impact on the project’s overall design, both at a macro and micro level. A registered brownfield, this designation meant that specific monitoring and engineering must occur to ensure compliance. As a result, all water lines which daylighted water must divert the water to a sanitary sewer, as opposed to a storm sewer. Further, a storm scepter was installed to capture contaminated groundwater, which was also delivered it to a sanitary sewer. Lastly, the site’s air, water, and soil were monitored throughout the course of the project for irregularities.
Located in Savannah’s National Historic Landmark District on a site known as Trustees’ Garden overlooking the Savannah River, both historic preservation, agency requirements, and aesthetics also played an important role. Both on the exterior and interior, historic material was retained whenever possible with all new elements designed in keeping with the period of the complex and all additions purposefully distinct but compatible. Further, the rear glass tower addition takes advantage of the site’s viewshed looking north. This, paired with multiple terraces, capitalizes on the rare urban green space situated north of the site, just south of the river.
On a micro scale, the site’s unusual topography on the Savannah River bluff meant that the project must accommodate and cater to multiple elevation changes as the iron works sits on one of Savanah’s only hills. As a result, the site’s 2,000 square foot catering kitchen is located almost entirely below grade with a terrace above. Accessible to pedestrians and cars along the building’s secondary, west elevation at grade, the kitchen accommodates an important event space need while remaining largely hidden.
Similarly, just north of the west foundry building, an underground storage building is situated below grade adjacent to a neighboring historic foundation. Requiring significant shoring design to ensure the preservation of the neighboring building’s foundation, the placement of the space in this location proved particularly beneficial as it was central to the overall site. Like the kitchen, the storage building is capped by a terrace with accessibility along the west elevation at grade. Along this facade, a roll-up door that opens onto an interior lift provides for the easy transfer of tables and chairs from storage for use throughout the complex. Adjacent, ticketing windows facing the complex’s central entrance corridor hide the west wall of the storage space beyond while providing an essential function to the complex’s success.
