Detached slabs of 5 to 15 stories are one of the most prolific residential types in London. These are accessed either directly from the street or through a front garden or plaza. Ground levels integrate lobbies, private amenities, and occasionally commercial uses. Apartments commonly run along double loaded corridors served by one or several vertical cores with lifts. Although external gallery accessed duplexes were once common, current developments mostly present single story apartments with balconies. Almost all affordable, or partially affordable, housing schemes occur in slab developments.