An English basement is the finished lower level of a building, generally in an older urban area, which is partially above and partially below ground level. English basements were originally designed to be rented out as separate apartment units and typically include all of the amenities needed for a full apartment. Access to English basements is normally separate from access to the main area of the structure, although an entryway space may be shared as not all English basements have separate exterior staircases up to street level.
This type of apartment originated in London and was very common during the Victorian era in densely populated urban areas. They can be found in London, New York, Moscow and any other city where living space was at a premium. Although they went out of fashion for a time, improvements in basement design technology and increasing urban property values have led to their reappearance, and many newer properties in urban population centers will include them.
Several basic architectural problems may be present in an English basement. Since they are located partially below ground level, the level of natural light is generally poorer than in the other parts of a dwelling. As modified basements, they also suffer from the same flooding issues that plague all types of basement. Older versions were notoriously damp and unhealthy, whereas their modern counterparts are generally acceptably dry, save for instances in which drainage or waterproofing systems fail, in which case they can suffer serious flooding damage.
Owners of townhouses or small apartment buildings with unfinished basements can add substantial additional living space or income potential by turning the basement spaces of their buildings into English basements. The first phase of this process typically involves upgrading the drainage and waterproofing in the basement and usually requires the partitioning of the basement, since large appliances such as water heaters will most often need to remain there and require both space and access. Utility services to the building must also be modified if the new English basement is to be rented out.
Once the structure of the basement space has been modified, it can be converted into rental space or in some cases, sold separately as a condo unit. Building codes may require additional modifications to allow an English basement to be safely inhabited, but the modification of a window to serve as a second exit or the addition of a second exterior staircase entrance or door will satisfy many of these requirements.