A "serviced apartment" is any size space for residential living which includes regular maid and cleaning services provided by the rental agent. Serviced apartments or serviced flats developed in the early part of the 20th century and were briefly fashionable in the 1920s and 30s. They are intended to combine the best features of luxury and self-contained apartments, often being an adjunct of a hotel. Like guests semi-permanently installed in a luxury hotel, residents could enjoy the additional facilities such as house keeping, laundry, catering and other services if and when desired. A feature of these apartment blocks was quite glamorous interiors with lavish bathrooms but no kitchen or laundry spaces in each flat. This style of living became very fashionable as many upper-class people found they could not afford as many live-in staff after the First World War and revelled in a "lock-up and leave" life style that serviced apartment hotels supplied. Some buildings have been subsequently renovated with standard facilities in each apartment, but serviced apartment hotel complexes continue to be constructed. Recently a number of hotels have supplemented their traditional business model with serviced apartment wings, creating privately owned areas within their buildings - either freehold or leasehold.