In 1777, he began the Hans Town development on 89 acres (360,000 m²) of open field and marsh leased from the Cadogan family. There he laid out parts of Knightsbridge and Chelsea, including Sloane Street and Sloane Square, and Hans Place, Street and Crescent. These developments quickly became some of the most fashionable areas in greater London. From 1802 Holland converted York House on Piccadilly into the Albany apartments.
Holland is perhaps best remembered for the original Marine Pavilion (1786–87) at Brighton, Sussex, designed for the Prince Regent, later King George IV. This and the celebrated remodeling of Carlton House, London (1783), exemplified his dignified neoclassicism, which contrasted with the more lavish style of his great contemporary Robert Adam.