What is of value is worth protecting. That is the fundamental premise in protecting buildings and their occupants and contents. In life safety design for buildings, the most valuable asset is human capital; the building is secondary to the people in it. When life safety design is for buildings of historic or landmark status, the history of a community is a priority as well.
Historic buildings represent society’s past achievements. Engineering them, so they continue to function effectively and efficiently in accordance with modern standards, is vital to their preservation. Creating life safety systems in keeping with both contemporary standards and the building’s historic fabric is, therefore, crucial, and it requires the use of specialized techniques.
The presence of so many historic and landmark buildings in New York City provides significant opportunity to reinvent our landmarks as modernized symbols of our past – and of our present and future. As a principal at Goldman Copeland, which has engineered such renowned buildings as the Empire State Building and Grand Central Terminal, I have been privileged to employ those specialized techniques in ways that can enhance historic buildings everywhere.
Upgrades to the infrastructure of historic buildings can be required by retroactive regulations, major renovations, or changes in use. A current example of a retroactive regulation is New York City’s Local Law 26/04, which requires the installation of fire protection systems in existing buildings. A result of task force recommendations after 9/11, Local Law 26/04 requires sprinklers to be installed by July 2019 in office buildings 100 ft. or more in height. Property owners have been and still are investing vast sums to achieve this unprecedented upgrade.
Installation of fire protection systems such as sprinklers in existing structures presents logistical challenges, due to physical and operational constraints. Work is often performed on overtime, with demolition and restoration of existing ceilings. These challenges, which elevate costs, are magnified in historic buildings which often contain elaborate decorative finishes.
Ideal solutions creatively integrate infrastructure improvements with the historic fabric of a building. One example is Goldman Copeland’s use of the original decorative grilles at Grand Central Terminal for an emergency smoke control system. The performance of the system was verified by fire modeling, a sophisticated tool often useful in structures calling for unique design solutions. Careful coordination with historic building experts – in this case, the architecture firm Beyer Blinder Belle – is key to successful execution.
Even without a retroactively enforced law, changes of building use or major renovations to historic properties typically require upgrades of existing fire protection systems. Due to the physical constraints of an historic property, a traditional design may not be feasible.
In engineering a recent conversion of an historic property, Goldman Copeland worked with local fire safety officials to develop a custom fire and smoke computer model to simulate conditions in a fire event. Modern technological tools enabled us to raise the historic building’s life safety to current standards by evaluating innovative design concepts through computer simulation. The innovative design for exhaust of smoke and introduction of fresh air was shown to provide equivalent performance to that of a more traditional design.
This introduces the concept of performance-based design. When compliance with current fire protection standards is not required due to grandfathered or landmark exceptions, design professionals can find themselves with no direct prescriptive guidance. The National Fire Protection Association provides an approach through its standards such as the NFPA 914 Code for Fire Protection of Historic Structures and the NFPA 909 Code for the Protection of Cultural Resource Properties. The process ceases to be “prescriptive,” where code officials dictate protection requirements, and becomes “performance-based,” where all project stakeholders work together to determine the goals and criteria of system design.
Most building code regulations in the United States are prescriptive in nature, though many codes allow for alternative methods and materials to be approved by local authorities. This has proved a reliable system of model code adoption and enforcement by state and local municipalities throughout the nation.
Many of our most cherished historic structures present challenges that are not addressed in prescriptive model building codes. Approaching this work with an established though innovative methodology based on performance and enforcing life safety design through common sense regulation are critical to protecting our cultural heritage.
Daniel Colombini, PE, LEED AP, is a principal, director of plumbing/fire protection at Goldman Copeland Consulting Engineers, New York, N.Y.