Bridgewater House

Bridgewater House is a large town mansion designed by Sir Charles Barry, with its final design completed in 1845 and construction finished in 1854 for Lord Ellesmere. The building is made of Bath stone and features a slate roof, showcasing a massive palazzo style that evolved from the architect's Reform Club. It consists of three storeys and a basement, with a single-storey coach house and a five-storey service wing on the east side, all maintaining the same overall height.

The mansion is nine bays wide, with vermiculated quoins. The ground floor exhibits smooth rustication and a prominent central porch supported by coupled Tuscan columns adorned with vermiculated banding. The ground floor windows are plain sash with semicircular arches, while the first-floor piano nobile windows feature bracketed segmental pediments and blind balcony balustrades. The second floor has plain square windows. Enriched bands are present at the first and second floor levels, along with a bracketed entablature and a balustraded parapet topped with large carved urns. The chimney stacks are corniced and rusticated.

The elevation facing Green Park consists of seven bays arranged in a rhythm of 1:5:1, with the outer bays featuring wide Venetian windows on the piano nobile. On the east side, the coach house has a blind wall with rusticated quoins and pilasters that divide three panels, topped with a balustraded parapet featuring ball finials. This is connected to the service wing along Little St James Street by a screen wall with double gates leading to a yard, flanked by gate piers with cast iron lamp standards. The service wing is faced with stucco and has rusticated quoins, with glazing bar sash windows, including one on the third floor that has a bracketed balcony and canopy. It is capped with a bracketed cornice and features corniced turrets at the angles, along with arches.

At the rear, there is a taller belvedere with coupled windows, corner turrets, and balustrades. The interior is grand and reflects a freely handled High Renaissance style, with the principal feature being a two-storey hall lined with marble and top-lit, which is arcaded on both floors. The interior has seen little alteration except for the picture gallery and has been restored after war damage, adapting the space for office use.