Lynnewood Hall is a two-story, seventeen-bay Classical Revival mansion that overlooks a terraced lawn to the south. The house is constructed of limestone and is raised one-half story on a stone base that forms a terrace around the perimeter of the building. The mansion is a "T" plan with the front facade forming the cross arm of the "T". Enclosed semicircular loggias extend from the east and west ends of the cross arm and a three-story wing forms the leg of the 'T' to the north. The most imposing exterior feature is the full-height, five-bay Corinthian portico with a stone staircase and a monumental pediment. The pediment contains a Classical figurative bas-relief and a circular window and is emphasized with modillions, dentils and egg-and-dart molding. Two-story, Corinthian pilasters are placed at two bay intervals around much of the building. Stone balustrades extend around the entire building at the raised terrace and the cornice line. The roof is flat and the cornice, like the pediment, is emphasized by modillions, dentils and egg-and-dart molding. The first floor windows are tall six-light casement windows with two-light transoms and bracketed crowns. The second floor windows are four-over-fourlight, double-hung sash with stone surrounds. All of the windows within the central portico are four-over-four-light, double-hung sash with stone surrounds. Those on the first floor have bracketed crowns. The principal entrance is centered within the front facade and has a modillioned crown over the stone door surround. The circular loggias have Ionic columns, six-light French doors with semi-circular transoms, and cornice-line balustrades. The doors open out to a terrace that can also be accessed by a stone stairway.
The north wing, or leg of the "T", consists of primarily the same Classical features as the cross arm. The west side includes a stone, one-story, three bay butler's entrance with Ionic columns and a balustrade. Originally there was a porte-cochere at the rear of the north wing. In 1910, however, the swimming pool north of the porte-cochere was enclosed with a squash court and changing rooms on the first floor and a gallery added above. The porte-cochere became an arched breezeway connecting the main house to the new addition. The breezeway--above which is the Bellini/Cellini Gallery--is covered with slate and is lit by a round dormer with a leaded spoke design. The first floor of the rear addition is rusticated, while the two-story upper section has stone pilasters and detailing that creates a false window or recessed panel appearance.
Lynnewood Hall is an immense structure that stretches approximately 365' east to west and contains roughly 110 rooms. The principal entrance leads into a two-story grand hall with a black and white checkered marble floor and a coffered ceiling which had a predominately yellow stained-glass panel at the center of the coffered cove. The opulent grand hall features full-height Composite pilasters flanked by large stone arches. A grand staircase with a decorative iron rail rises at the north end of the hall. Directly north of the staircase landing is a library (originally a tea room with French decoration including a mother-of-pearl-like elongated dome, centered in the ceiling), while to the east and west, the staircase splits to winding stairs which lead to the second floor balcony. The balcony overlooks the grand hall and contains a coffered ceiling and an elaborate iron rail.
The vast wings that comprise the cross arm of the "T" extend east and west from the grand hall. The east wing included a reception room to the south, a gallery to the north, and a hall leading from the grand hall to the ballroom and attached porch. The west wing consisted of a smoking room to the south, a pantry to the north and a hall leading to the dining room and attached breakfast room, safe and enclosed porch. The east wing's second floor was primarily bedrooms and private living space for Widener's elder son George and his wife Nellie and their children Harry, George and Eleanor. The west wing's second floor contained the living quarters of the master, his son Joseph and his wife Ella and their children Peter A.B., II, and Fifi.
The ballroom is an elaborate space measuring 2550 square feet. The walnut-panelled walls are decorated with Composite fluted columns and pilasters embellished with gold leaf. The lavish ceiling contains filigree plaster and leaf work, relief angelic figures within the cove, and bands of floral motif molding, all accented with gold leaf. The most imposing feature, however, is the large circular painting in the center framed by an elaborate plaster molding covered with gold leaf designs and flanked by eight smaller paintings, also framed by ornate plaster moldings with gold leaf highlights. The gallery next to the ballroom has been significantly altered, yet it still features a beautiful polychrome wood beamed and panelled ceiling.
The north wing contained the library, Widener's office and servants' areas on the first floor, while the second floor contained the guest bedrooms, the tea room and the art galleries. There was also an indoor swimming pool, a squash court and a large art gallery, known as the Van Dyck Gallery, in the rear addition.
The grounds were originally heavily terraced with elaborate gardens. In 1920, Jacques Greber, the French landscape architect who had redesigned the suburbs of Paris and laid out Benjamin Franklin Parkway in Philadelphia, was hired to redesign the landscape of Lynnewood Hall. Greber laid out a rose garden along the west side and a formal garden with a fountain along the east side. He also included parterre gardens, large trees and other tall plantings along the east drive court as a screen for the galleries. An intricate drive wound throughout the estate, passing many spectacular fountains, said to have rivaled those at Versailles.
The interior and grounds of Lynnewood Hall have been significantly altered and are in great need of repair and restoration. Several rooms including the ballroom, reception room, smoking room and breakfast room retain significant architectural elements, however, due to very limited access, most of the building could not be documented.