Influenced by government structures, much of the city's architecture tends to be formalistic and functional; the city is also marked by Romantic and Picturesque styles of architecture such as the Parliament Buildings' gothic revival architecture. Ottawa's domestic architecture is dominated by single family homes, but also includes smaller numbers of semi-detached houses, rowhouses, and apartment buildings. Many domestic buildings are clad in brick, with small numbers covered in wood, stone, or siding of different materials; variations are common, depending on neighbourhoods and the age of dwellings within them.