PRESERVATION Tech Ifotes NATIONAL PARK SERVICE u .S. DEPARTMENT OF INTERIOR WASHINGTON, D.C.

HISTORIC INTERIOR SPACES

NUMBER 2

Preserving Historic Office Building Corridors

Tbomas G. Keoban Division of Cultural Resources Rocky Mountain Regional Office National Park Service The Monadnock Building Chicago, Illinois

Hailed as one of the finest expres­ structure on the clay and soft sand in sions of the "Chicago School" of the Chicago area. The building's architecture, the Monadnock Building wind-bracing system, terra-cotta fire­ was one of the country's first proofing, and flat-arch construction skyscrapers and the largest commer­ system were among the earliest used. cial building in the world at the time The south half of the building was of its completion. Built in 1892 and designed by the architectural firm of expanded in 1893, the Monadnock Holabird and Roche and was Building is individually listed in the completed in 1893. It used a combi­ National Register of Historic Places nation of masonry-bearing elements and also located in the South and a steel frame structure. Although Dearborn Printing House Row Historic District. the design of the south half reverted The north half of the Monadnock to the use of European ornamenta­ Building, designed by the architec­ tion, it complemented the north half tural firm of Burnham and Root, is of the building in scale, color, and notable in many respects. Its engi­ plan. The interior of the south half When rehabilitating historic office neering is significant still today in was similar to the design of the north buildings, significant corridors should that it is the largest and tallest with double-loaded corridors and be preserved whenever possible, and masonry load-bearing building in the office partitions featuring marble new mechanical equipment should be world. Burnham and Root, used a wainscot, oak trim and feather­ installed in such a manner so as to "grillage" foundation to deal with chipped glass. preserve significant interior spaces, the problem of erecting such a large features, and finishes. Burnham and Root's design for the bays. Light entered the double-loaded open stairwells and elevator shafts. interior was to bring light and air corridors and public spaces through The narrowness of the building gave into the building through large one­ feather-chipped glass office and occupants good access to natural over-one windows and projecting corridor partitions, and skylights over light (See figure 1).

North South

Detail of North Corridor

Detail of South Corridor

Figure 1. Both north and south building floor plan, showin~ double-Ioa~ed corr~dor sys~em. Sha~~d are~ indicates ~r~pped ceiling for mechanical chases in the non-public anterooms. Public COrridors and prtvate offIces retam full celhng heIght. Drawmg. Neal Vogel

2 REHABILITATION DESIGN office doors and transoms had been corridors, enclosing the open orna­ PROBLEM removed or covered over. On several mental staircases with fire-rated glass, floors the corridors had been entirely and replacing existing elevators. A removed or shortened to accommo­ second option explored keeping the The Monadnock's historic interior date open floor plan offices. (See original corridor plan, but upgrading corridors and office suites had figure 2). it with new drywall surfaces and suffered considerably because of past After the building was purchased dropped ceilings to hide linear insensitive remodeling. Prior owners by the present owners in 1979, several mechanical systems. The spaces had dropped ceilings for mechanical options for its rehabilitation for behind the corridors would be left equipment, removed large sections of office use were considered. The first open to suit individual tenants. Both the historic marble wainscotting, and option involved vacating the building options are frequently seen today in painted over the ornamental cast-iron of tenants and removing interior various forms and are popular, staircases and bronze door hardware. walls and finishes to accommodate an though in the case of historic office Almost all of the feather-chipped open floor plan. This would require buildings, such treatments may either glass partitions, oak trim, and glass the demolition of all remaining be inappropriate or unnecessary.

Figure 2. Typical condition of public corridors prior to rehabilitation. Glass and oak corridor partitions and much of the marble wainscot was either removed or covered. Ceilings were suspended and sections of the corridor plan were shortened or removed. Photo: William S. Donnell 3 DESIGN SOWTION revenues, and construction could construction would have cost around continue on an as-needed basis as $25 per linear foot, the cost of tenants leased the reconditioned replacing marble wainscotting, oak A third, more historically sensitive floors. The owners recognized that trim, and glass partitions cost option was chosen. This option the Burnham and Root design, with approximately $400 per linear foot. involved retaining the existing historic its double loaded corridor and use of This more expensive treatment was corridors and re-establishing corridors high quality materials, could provide economically feasible because of the to match the historic ones on floors a "timeless environment" suitable for overall savings realized by using the where they had been removed. The today's office market and would not building's existing heating system; by plans also called for smaller indi­ be quickly outdated and needing maintaining rather than rebuilding vidual offices with a basic office further renovation within a few years. existing intact serviceable corridors; module of about 600 square feet, by using an efficient decentralized air which was close to the size of the conditioning system; and by receiving historic office suites. (The marketing specific building code variances given plan targeted lawyers and other OFFICE CORRIDORS to historic buildings. professional businesses requiring Typically, the ceilings in office smaller office spaces). Many technical, economic and building corridors are dropped to Historic drawings were used as the aesthetic considerations influence the allow for mechanical chases to run basis for reconstructing the missing design of a corridor system in an longitudinally through the building. corridors according to Burnham and office building. In the case of the Retention of the Monadnock's Root's original design. Rehabilitation historic Monadnock where the intent historic plaster ceilings in the corri­ plans also included the repair and was to retain the historic corridors dors was possible by locating rebuilding of missing sections of the and replace missing features, the mechanical systems above dropped ornamental iron staircases. A few work was influenced by decisions ceilings in the non-public space existing corridors, though missing concerning the mechanical and elec­ adjacent to the corridors. These some historic features, were left intact trical systems, stairs, wall finishes, secretarial anterooms are located with plans to replace the missing and door hardware. If not handled between the corridors and private historic elements sometime in the with sensitivity, these building office bays (See figures I, 3, and 4). future. This allowed the building to elements could have compromised the Approximately one-third of the remain occupied during the design and features of the historic corridors were missing before the rehabilitation. corridors. rehabilitation began. Such areas were This design solution was chosen for Historic drawings microfilmed by rebuilt to the historic configuration. several reasons. The building's long, the Historic American Buildings Another one-third required some narrow plan and bay window Survey in 1954, together with physical remodeling of existing wall finishes construction lent itself to smaller evidence uncovered during the reha­ and floor plans, while the remaining individual offices served by a double­ bilitation, provided a basis for the one-third required minimal work such loaded corridor. The building could reconstruction of the missing historic as repairing and replacing office be rehabilitated without a major corridor and office partitions. Where doors and door hardware, removing disruption and loss of tenant typical drywall paint, and refinishing wood trim.

OFFICE SECRETARIAL

~r' ____ ~l~'______~~'

Figure 3. Building cross section showing open stairs and full height ceilings in corridors and private offices. Glazed corridor partitions are feather-chipped glass. Drawing: Montauk Company

4 lOO-foot intervals. Each office suite is II then serviced by individual heat ( I pumps connected to a riser on each floor. Duct work to supply the condi­ tioned air is concealed by the dropped ceilings in the anterooms. By breaking the air conditioning system into smaller components of ANTEROOM OFFICE individual heat pumps, and using the existing steam heat system, the amount of required mechanical space was reduced. By reducing the neces­ sary mechanical space and evenly distributing the heating and air conditioning systems throughout the building, smaller mechanical chases could be located in anterooms, thus eliminating the need to lower historic Figure 4. The innovative rebabilitation solution places dropped ceilings only in the corridor ceilings. anteroom, thus preserving the important historic features in the public corridors and Upgrading the electrical distribu­ private office spaces. The dropped ceiling area is large enough for future expansion of tion system provided a challenge in mechanical and electrical systems. Drawing: Neal Vogel corridors that retained the full MECHANICAL AND The German Ammark valves are ther­ historic ceiling height. Floor sections ELECTRICAL mostatically controlled and regulate in the Monadnock are constructed of both steam and return condensation 12-inch to 13-inch hollow terra-cotta in one pipe. Considerable space was tiles topped with a cementitious The Monadnock was purchased in saved by using the existing steam mortar and finished below with 1979 by the current owners for $5 per system, and avoiding massive forced ceiling plaster. Running new electrical square foot. The original one-pipe air duct work or piping for a new conduit through the hollow floor steam heating system was still in steam system (see figures 5 and 6). sections was explored, but rejected place at the time. Rather then replace Likewise, large volumes of space because of misalignment of the terra­ the existing system with a more costly were saved by installing a new space­ cotta sections. An alternative solution forced-air unit, the steam system was efficient air conditioning system. proved to be more feasible. A new repaired for less than $1 per square Individual window units were primary electrical distribution system, foot. This included new boilers and replaced by a central cooling tower together with a backup emergency controls, asbestos abatement, and located on the roof, featuring four system, was new Ammark valves at the radiators. vertical risers through the building at

Figure 5. lYpical pre-rehabilitation condition in private offices. Figure 6. lYpical 600 square foot office module after rehabilita­ Approximately 60 percent of all office interiors had suspended tion, with full ceiling height and one stand pipe radiator heat. ceilings, blocked-down windows and radiator enclosures. Note Photo: Ron Gordon inappropriate way dropped ceiling abuts windows. Photo: William S. Donnell 5 installed in the building by carefully channeling the ceiling plaster and attaching 3/4-inch oval conduit to the hollow terra-cotta floor sections. The channels were then replastered to match the surrounding ceiling (See figure 7). Dropped ceilings in the anterooms also provided for electrical chases servicing secretarial and private office spaces.

ORNAMENTAL STAIRS AND BUILDING HARDWARE The ornamental open staircases are significant architectural features and Figure 7. Channeled corridor ceiling with owl electrical conduit installed. Replastered a major focal point of the corridors channel matches existing ceiling, concealing new electrical distribution system for the entire building. Photo: William S. Donnell in both the north and south halves of the building (See figure 8). Beyond the total new construction costs reheated in the manufacturing process their architectural significance, the remain under 50 percent of the esti­ to form a dark corrosion-resistant stairs in the north half of the mated cost to reproduce the entire finish simulating cast oxidized building from street level to the first original building. For most historic bronze. During the course of the floor are cast aluminum and repre­ buildings, the reproduction costs rehabilitation, missing and damaged would be staggering, allowing rehabil­ sent the first use of this metal in a hardware was replace with actual cast building. Upper flights are made of itation costs to be well below 50 oxidized bronze (See figure 9). As a bronze-plated cast iron. These open percent of the estimated reproduction stairs were allowed to remain intact costs. result, these important historic under a provision of the Chicago Originally the Monadnock featured features remain significant elements Building Code that waives certain Bower-Barff cast-iron door hardware, within the Monadnock's corridors. code requirements for buildings where which is cast iron that has been

Figure 9. Original cast-iron door Figure 8. Burnham and Root's aluminum and bronze plated cast-iron stair remains the hardware retained in corridors. most notable architectural feature in the north half of the building. Minor repair work Photo: Ron Gordon and a few missing elements have been replaced with cast aluminum. Favorable building codes allowed the open design. 6 EVAWATION The success of the rehabilitated that has been stripped of its historic Monadnock building can be finishes. measured by its tenant occupancy. The innovative design solutions The rehabilitation philosophy of Before the rehabilitation started, the employed in the Monadnock show retaining and repairing historic average office suite leased for $4.75 corridor fabric where possible and that retention of historic corridors in per square foot. Today average office office buildings can be not only cost replacing missing elements to match suite leases exceed $14 per square effective and feasible, but may also the historic plans proved to have an foot, with a vacancy rate of less than be a desirable alternative to more economic advantage over comparable 4 percent. Compared to new class new construction. While typical •'N' office space in Chicago with radical and intrusive rehabilitation office rehabilitations in Chicago leases averaging $25 per square foot, treatments. require an average investment of $100 and a 14 percent vacancy rate, the per square foot, the rehabilitation of Monadnock with its historic interior the Monadnock cost under $50 per is a competitive alternative to new square foot (See figure 10). construction or rehabilitated space

Figure 10. Rehabilitated corridor showing marble wainscot, oak and feather-chipped glass corridor partitions, full ceiling height and open ornamental stairs. Photo: Ron Gordon

7 PROJECT DATA:

Building: Architect: Project Costs: The Monadnock Building John Vinci, Architect The average cost per floor of rehabil­ 53 West Jackson Boulevard Chicago, Illinois itation for the north and south halves Chicago, Illinois of the building is approximately $1 million dollars or $47 per square foot. This includes the cost for repair or replacement of missing historic Owner and Developer: Project Dates: corridor and office wall components, ornamental staircases and building Montauk Company 1979 to Present hardware, new electrical distribution Chicago, Illinois systems, new air-conditioning systems and retrofitted steam-heat system.

This PRESERVATION TECH NOTE was prepared by the Division of PRESERVATION TECH NOTES are designed to provide practical infor­ Cultural Resources, Rocky Mountain Regional Office, National Park mation on innovative techniques and practices for successfully maintaining Service. Charles E. Fisher, Preservation Assistance Division, National Park and preserving cultural resources. All techniques and practices described Service, serves as Technical Coordinator for the PRESERVATION TECH herein conform to established National Park Service policies, procedures, NOTES. Information on the rehabilitation project was provided by and standards. This Tech Note was prepared pursuant to the National William S. Donnell, President, The Montauk Company. Historic Preservation Act Amendments of 1980 which direct the Secretary of the Interior to develop and make available to government agencies and individuals, information concerning professional methods and techniques for t he preservation of historic properties.

Comments on the usefulness of this information are welcomed and should be addressed to Tech Notes, Preservation Assistance Division, National Park Service, P.O. Box 37127, \Y.ishington, D.C. 20013-7127. This publica­ tion is not copyrighted and can be reproduced without penalty. Normal procedures for credit to the author and the National Park Service are appreciated.

ISSN: 0741-9023 PTN-26 July 1989

8 GPO 676-4170