Life Safety Upgrades In Historic Buildings
September 23, 2013
Retrofitting more than a half-million square feet of heavily used space for better life safety coverage is never simple. Peculiarities of building design and existing materials only made the task tougher for this project team as they sought to integrate NFPA and GSA requirements into a successful and safe solution.
Modern building and life safety codes were primarily developed in the 20th century in reaction to intense urban development and a series of unfortunate disasters that resulted in the loss of human lives. For almost 100 years, these codes focused solely on new construction. However, in the 1960s, the historic preservation movement in the United States coalesced at both the state and federal levels, posing special compliance challenges, particularly for life safety code requirements.
As the historic preservation profession has matured and life safety codes have been refined, owners, designers, and contractors are continuously challenged to develop design and construction solutions that meet current life safety standards while preserving the materials and spaces that make landmarked buildings special.
First, some background on GSA. The U.S. General Services Administration’s goal is – “to deliver the best value in real estate, acquisition, and technology services to government and the American people.” GSA serves as the landlord for the civilian federal government and acts as a caretaker for federal properties across the country. Additionally, it owns or leases 9,624 assets, maintains an inventory of more than 370.2 million sq ft of workspace for 1.1 million federal employees, and preserves more than 481 historic properties. These properties represent the work of prominent architects and are valued for their significance in American history, architecture, art, archeology, engineering, and culture.
Currently, more than 300 GSA properties are listed in the National Register of Historic Places. Many of the historic properties in GSA’s portfolio serve critical public functions, including federal courthouses, and GSA must balance the requirements of life safety, historic preservation, security, programmatic function, and sustainability.
The Birch Bayh Federal Building and U.S. Courthouse, located in Indianapolis, is one of the most architecturally significant buildings in GSA’s Great Lakes Region. The building was constructed in 1905 with an addition completed in 1938. This full city block Beaux Arts-style building, with more than 540,000 gross sq ft of useable space, originally served as the home for the U.S. District Court for the District of Indiana and as Indianapolis’ U.S. Post Office. Currently, the building is occupied by the U.S. District and Bankruptcy Courts for the Southern District of Indiana and provides office space for numerous other federal agencies.
GSA, with EYP Architecture & Engineering as the lead designer/ historic preservation consultant, recently completed a $74.4-million renovation of the courthouse under the American Recovery and Reinvestment Act of 2009. Constructed in phases over a 32-month period, the Design Excellence/Construction Excellence project included improved energy efficiency, emergency preparedness systems, and preservation and restoration of original building features. Additionally, the project was accomplished with minimal relocation of tenants and with nominal impact to the building’s historic fabric.
The building has been well maintained by GSA, including a significant renovation in the 1970s, but the life safety systems, particularly the fire suppression system, did not meet current standards. The existing fire suppression system provided only limited area coverage with both wet and dry automatic fire sprinkler systems and a standpipe system with firemen’s connection on each floor. The wet pipe system covered only the basement of the building and the dry pipe system the loading dock and garage.
In addition to the limited coverage, the water supply for the fire suppression was not a dedicated supply, which posed a significant risk. While the primary purpose of fire suppression is to promote life safety both for the occupants in the building as well as the first responders, these systems also serve a critical role in preserving historic buildings and offering mission continuity in critical facilities. Providing a comprehensive yet sensitively designed and installed fire suppression system was a key component of this renovation project.
When developing a design for new building systems in an historic building, there are numerous stakeholders that should be involved from the initiation of the process. The fire suppression system design at the Birch Bayh Building benefitted from input from the GSA regional fire protection engineer and GSA regional historic preservation architect, the design team, consisting of an historic preservation architect and fire protection engineer, as well as the general contractor and fire suppression subcontractor. As a Design Excellence/Construction Excellence project, the team had the added benefit of having the general contractor, Shiel Sexton, and the fire protection subcontractor, Ryan Fire Protection, available from the start of the design process. The result of having all of these parties involved early on in the design development process was that every idea that was discussed and analyzed was studied concurrently for performance, historic preservation impact, constructability, and cost.
Finding one design solution that fully satisfies all of the functional, aesthetic, budgetary, and scheduling criteria is highly unlikely. An option that may be best for performance, for instance, may require damaging important historic materials or may be very costly to implement. It is vital, therefore, that the entire team commit themselves to looking at the building and the problem holistically. While each team member is there to advocate from their own perspective, they must also understand the approach of other team members. The challenge is to reach consensus on solutions that best meet the range of criteria.
One example of this collaboration at the Birch Bayh Building is the first floor public corridor, elevator lobbies, and the monumental stairs. Architecturally, these represent the most visible historic spaces and are key to understanding the building’s original design concept as both a U.S. post office and federal courthouse.
The finishes in this area, including the marble paneled walls and mosaic tile vaulted ceilings, are representative of the quality of materials and design that permeated government buildings in the early 20th century. However, these uninterrupted spaces, both horizontally and vertically, posed special concern from a life safety perspective.
A key step in reaching agreement on the overall plan for upgrades was that the open nature of the spaces could remain if the fire suppression system achieved 100% coverage of the entire building. The challenge was now in the hands of the design team and the contractors. Could a fire suppression system, including pipe routing and heads, be devised to provide full coverage in these incredible spaces?
A code analysis was developed by the design team’s fire protection engineer, RTM Consultants, Inc., to help determine how to best provide a reliable system to protect building occupants, firefighting personnel, building contents, building structure, and continuity of building function. The design intent was to provide a reasonable level of fire safety by reducing the probability of injury, loss of life, of building function changes due to a fire. This could be accomplished by limiting the development and spread of a fire emergency to the room or area of origin, allowing additional time and safety for evacuation.
Due to existing deficiencies in the means of egress requirements and unprotected vertical openings to the 2003 Life Safety Code, a fire safety evaluation system was performed in accordance with NFPA 101A-2004 edition. This evaluation provided a methodology for addressing the existing deficiencies without requiring modifications to critical historic materials and spaces. With the proposed installation of a complete quick response automatic sprinkler system using extended throw sprinkler heads in key areas, the levels of fire safety for this building were shown to be at least equivalent to NFPA 101. All new work would also be in compliance with the current GSA adopted NFPA standards. All abandoned or non-compliant components of the existing fire suppression and life safety systems would also be removed.
Since every surface and material in these spaces was sensitive and historically valuable, the design team and GSA evaluated op-tions for locating sprinkler heads in a priority fashion. The mosaic tile ceiling had cavity space behind it for routing piping, but the tiles were too fragile and the risk of damage when creating penetrations for sprinkler heads was too high. Therefore, the surface was only an option if no other possibilities were available.
Two installation locations are representative of how this process was applied. In the main cross corridor, the arched openings on the north and south walls were originally part of the post office. Office space, retail functions, and the main sorting room were located on either side of the corridor, benefiting from the natural light that penetrated into the building from the south through the glazed, arched openings. Suspended ceilings were installed in those areas in the 1970s, offering a plenum space for the routing of new piping. The target location for the sprinkler heads was the 4-in wide wood frame at the peak of each arch. This location, at the highest point of the ceiling, met performance requirements, and limited the alterations to the least sensitive of the materials and was the least expensive material to penetrate.
The second, and much more complicated spaces, were the two octagonal vestibules at either end of the main cross corridor. The primary public entry points to the building connect to the elevator lobbies and monumental stairs. The lower walls are sheathed in marble with a vaulted mosaic tile ceiling above. While there is virtually no fire load in these spaces, the agreed upon concept design where the open stairs could remain unaltered with full sprinkler coverage of the building, required that the team find a way to insert sprinklers in these two spaces. With the mosaic tile off limits, the team agreed that if sidewall sprinklers could be inserted as high as possible on the marble wall, the coverage would be sufficient for the space. Using 1905 construction drawings as a guide, triangular cavities located behind the four solid walls were identified as sufficient for routing piping up from the basement that could reach a point just below the marble entablature.
While the design team, in coordination with the contractor, identified acceptable pathways and termination points in these highly sensitive areas, skilled craftspeople were still required to make the installation a success. The initial steps in this process were for the subcontractor to review each location to verify their understanding of the design intent, identify any barriers to success, and most importantly, to suggest modifications to the design that would simplify the installation while maintaining the end result.
At the arched openings, while there was adequate room to maneuver above the ceiling there were concerns regarding the precision required to align the distribution sprinkler piping with the head location, which needed to be centered exactly on the wood trim. To provide a margin of error the team agreed to utilize a flexible connection between the primary sprinkler line and the head. The application of a flexible connection, more common above suspended ceilings to allow for future relocation of heads if a space’s layout changes, allowed a very high level of precision on the location of the actual sprinkler head.
The more complicated installation was at the octagonal vestibules. While the triangular cavity was large enough for workers to ac-cess, it was separated from the finished space by a 36-in thick load-bearing brick wall and 1-in thick marble panels. Test drilling of the brick in a basement location informed the teams that dry core-drilling was not an option; the brick was too hard and too thick. Wet core-drilling was discussed, but the application was restricted to the cavity area to prevent water from damaging the marble finishes in the vestibule, and the cavity was not large enough to set up a drilling rig.
The craftspeople then developed and tested a hybrid approach. They first drilled a small pilot hole through the brick from the finished side to control the location. With this completed they wet core-drilled from the finished side. The pilot hole acted as a “relief vent” for the water as it flowed into the cavity away from the marble finishes, where it could be collected and safely removed. The sprinkler heads were installed precisely and the system was piped.
Once the methodologies for installing each head and the required piping were established, the team developed a management approach to ensure that each location received the same level of care and quality. The first step in this process was identifying a specialty subcontractor, a firm with experience in the restoration of marble and plaster, and assigning them the responsibility of all cutting operations. Typically, each discipline subcontractor is responsible for cutting and drilling for their systems, but by centralizing the responsibility, the team had better control over the process.
The second step was the development of a work plan for cutting through each type of material. Similar to most projects, the specifications included a requirement for a written work plan and mock-ups. The contractors took this effort to a higher level, creating videos that illustrated the tools and work processes that they would utilize. These videos were reviewed and approved by GSA and EYP’s historic preservation specialists remotely from the site and were then used as instructional tools for any workers on site involved in the cutting and drilling work. The added value is that GSA now has instructional videos in their archives that can be used for similar projects in the future.
The final step prior to construction work proceeding in any location was a site walk-through attended by all the team members to review each sprinkler head location in sensitive areas. Locations were marked with painter’s tape to verify the precise location and installation methodologies were reviewed. A sign-off form for each location confirmed that the design criteria had been satisfied and the contractor was authorized to proceed.
A successful project requires a team approach from design through construction. Only through the shared knowledge and experi-ence of all the team members can the most creative solutions be developed and implemented. The renovation of the Birch Bayh Building will extend the useful life of this landmark for another century for the benefit of future generations.
The rehabilitation and reuse of historic buildings has increased and will continue to increase as a project type in the design and construction industry. Change in our world is inevitable. Denying the reality of change is counterproductive when working with historic buildings as it would transform them from active, useful buildings into museums. While the objectives of life safety and historic preservation may seem at odds with each other it is possible — and critical — that we find creative solutions that satisfy both requirements.