Instead of expanding up when tacking on an addition to their house, residents are building multiple storeys way, way down, according to a Globe and Mail article.
Known as iceberg homes, the majority of these mansions exist underground and out of sight. Many people use as many as four new floors to build tennis courts, swimming pools, and even ballrooms below the street.
Due to soaring house prices and strict regulations on above-ground construction, the wealthy are using the iceberg method to add square-footage and value to their homes.
Popular in Kensington Chelsea, and Knightsbridge, many residents are fighting these underground expansions and pushing London to change laws and real estate regulations.
Like all local councils in Britain, the Royal Borough of Kensington and Chelsea has strict laws on above-ground home renovations, but few for basements.
Neighbours of basement expansions have experienced their own homes sinking, cracked doorways, and thousands of dollars in damage. In some cases residents were even trapped inside their homes.
Along with personal property damage, The Guardian reports that the subterrain additions will affect the areas’ ability to cope with heavy rain. The thick concrete walls will prevent water from soaking away and increase the risk of flash flooding. In other words, your house could fill with water because your neighbour really, really wanted to install an underground tennis court.
The Kensington and Chelsea council is thinking of limiting basement additions to one storey as well as prohibiting all underground expansions on historic properties and gardens.
Other councils are waiting to see the decision Kensington and Chelsea will make before moving forward with changes in their own towns.