A street of British terraced housing

In architecture and city planning, a terrace, rowhouse, or townhouse (United States) is a style of housing since the late 18th century where identical individual houses are cojoined into rows. A terrace is also the term used to refer to paved, unroofed areas that open out from a building, usually in residences at upper floor levels.

The term terrace was borrowed from garden terraces by English architects of the late Georgian period to describe streets of houses whose uniform fronts and uniform height created an ensemble that was more stylish than a "row". The "row", as in the 16th-century Yarmouth Rows in Great Yarmouth, Norfolk, was a designation for a narrow street where the building fronts uniformly ran right to the property line.

Early terraces were built by the Wood family in Bath and by John Nash in Regent's Park, London, and the name was picked up by speculative builders like Thomas Cubitt and soon became commonplace.

Terraced Houses in Stanford in the Vale, Oxfordshire.

By the early Victorian period, a terrace had degenerated into any style of housing where individual houses repeating one design are conjoined into rows, which can be long or short. The style was used for workers' housing during the great industrial boom following the industrial revolution, particularly in the textile industry. The Terrace style spread widely in the UK, and was the usual form of high density residential housing up to World War II.

In New York City, a large apartment building occupying a full city block, London Terrace, finished in 1930/1931 capitalized on the earlier, more stylish connotation. Terrace housing in American usage generally continued to be called rowhouses in the Eastern U.S., but west of the Mississippi, "townhouse" is preferred.

See also: Duplex, Semi-detached, Townhouse, List of house types