Stoneleigh, a 42-acre estate in Lower Merion Township, Montgomery County, was extensively restored and rehabilitated to accommodate its tenant, the Organ Historical Society, and various education seminars, symposia, concerts and fundraisers. The goal of creating a more accessible, comfortable, functional and hospitable space was achieved by discreetly incorporating accessibility and building system upgrades into the historic 20,000 square foot mansion. A new elevator and code compliant stair were designed to carefully integrate into the existing millwork, while conserving the existing architectural details of the house. Constructed in the Victorian style between 1877 and 1890 by Edmund Smith, executive of the Pennsylvania Railroad, the estate was extensively renovated and enlarged in 1902, transforming the Victorian house into a Tudor Revival-style residence. The estate, including formal gardens designed by the Olmstead Brothers in the 1930s, was donated by the Haas family to Natural Lands in 2016 in order to be preserved for the future enjoyment of the public.