Keret House is a structure and art installation in Warsaw, Poland. It was designed by the architect Jakub Szczęsny through the architecture firm Centrala, and has been described as the narrowest house in the world.

The iron structure contains two floors and has one bedroom, a kitchen, a bathroom, and a living area. It has two non-opening windows, with sunlight also entering through translucent glass panels that make up the walls. The entire interior is painted white and the building’s electricity is obtained from a neighboring building. The house has custom water and sewage technology and is not connected to the city-provided water systems. Because of its small size, the building only accommodates a small 2-beverage refrigerator, and occupants use a ladder to travel from level to level. Entry is via retractable stairs that, when closed, become the living area.

The construction of the Keret House was supported by the Warsaw Town Hall and was produced and realized by the Polish Modern Art Foundation. The house is classified as an “art installation” because it does not meet Polish building codes, even though it is being used as a residence.

In 2019, it was named one of the most iconic houses in the world and included on a list of international projects honored by the architecture portal Iconic Houses.

According to Wikipedia