When William Fairfax came to Virginia, he brought many strong English traditions with him. The manor and grounds of Belvoir were laid out similarly to English estates. The brick, Georgian manor was the most sought after and fashionable architectural style in England and the colonies at that time, and its use here reflected the importance of the Fairfax family.
Belvoir was elegantly furnished with mahogany pieces such as a shaving desk, chests of drawers, a sideboard, and imported carpets. Fine mirrors and candlesticks decorated the house as well as a bust of Shakespeare and fine ceramic and glassware, all of which were imported and illustrated the family's high social status. The layout of Belvoir and its grounds was similar to other later estates in the vicinity, including Mount Vernon and Gunston Hall.
The house was described as having five rooms upstairs and four rooms downstairs, including a dining room and parlor on the Potomac River side. It was flanked by exterior chimneys and two central doorway entrances to serve the river and land approaches to the house. Beyond the inland doorway entrance was a courtyard garden.