Modern Systems / Historic Aesthetic

Installing modern HVAC systems was vital to preserving the building’s interior. The challenge was providing this modern amenity without compromising the Main House’s historical integrity. A thoughtful and sensitive approach led to the installation of archival-level climate control HVAC systems. Non-invasive mechanical system distributions were designed to conceal and minimize interior disturbances. This approach provided modern standards while preserving historic decor and aesthetics.



For critical areas, such as historic archival spaces and the rare books library, the unique HVAC systems provide precision cooling, heating, and humidity control. A new interior envelope with continuous vapor barriers and gasket doors also helps maintain the desired temperature and relative humidity to a tight tolerance, as required by museum and archival standards. Each space was designed as an independent zone with its own air handling unit and space controls, including thermostat, humidistat, monitoring, and fault alarms.



Lighting and electrical systems were also designed to minimize impacts to historical features. For example, specialty lighting, with lighting controls, was installed in spaces with historic appeal on the ground floor, while general illumination design was provided for other spaces. To help conceal the new electrical service required to support the property and garden upgrades, a garage was transformed into an electrical space with electrical panels, switch gears, transfer switches, and a back-up outdoor generator. Fire alarm systems, audio/visual, telephone/data, security, and site power/lighting systems were also installed.



An important part of Stoneleigh’s renovation was the facility’s new fire protection systems. Having so many historical elements, it was important that the Main House’s new design be sensitive to its interiors. A new fire protection system encompasses the entire house, without encroaching on points of visual interest. For example, a wet system with detailed pipe routing serves all non-critical spaces, with concealed sprinkler heads serving areas with original decorative ceilings and moldings. Critical areas, such as historical archival spaces and the organ pipe chamber, are served by a dry or non-water based FM-200 fire suppression system. A new fire pump provides the required flow and pressure for the new fire protection systems. The fire protection system is critical to safety of the Main House, which will be used for events.

Exemplary Historic Preservation

Stoneleigh: a natural garden is now open to visitors, free of charge. Thanks to the careful renovations by the design team, which included John Milner Architects, and Urban — who provided mechanical, electrical, plumbing and fire protection engineering services — patrons can experience the property’s historic cultural value.



“Stoneleigh is unique among our preserves in so many ways,” said Molly Morrison, former president of Natural Lands, to the PhillyVoice. “We envision a place where the public will be able to enjoy the quiet and beauty of the Stoneleigh grounds and be motivated to learn about the joys and benefits of gardens that emphasize the use of native plants. We are deeply honored to be entrusted to carry on the Haas family’s legacy of stewardship for this magical place, and excited beyond measure to add Stoneleigh as a unique, shining star in our constellation of preserves."