3D visualization shows the interior of the Keret’s House, one of the world’s narrowest houses at 1.2 metres, built in Warsaw, Poland. (Foundation of Polish Modern Art/Associated Press)

A new Warsaw house is only 1.2 metres wide, but it comes with a bathroom, a kitchen and a bedroom, and its first tenant, an Israeli writer, will move in this weekend.

Architect Jakub Szczesny said Friday he designed the two-story aluminum and plastic house three years ago to fill a narrow space between a pre-war house and a modern apartment block in downtown Warsaw.

The Foundation of Polish Modern Art and Warsaw Town Hall helped fund the project, which they consider an art work.

But it may not be easy for the tenants.

The triangular building runs 10 metres deep at the base and stands nine metres tall.

Metal and aluminum pipes hold the structure nearly 10 feet (3 meters) above the ground, and visitors will climb a metal staircase and squeeze through a hole to enter the building.

The ground floor contains a toilet and shower, a kitchen with a sink and cupboards, a table for two, and a bean bag sofa. Another metal ladder goes to the second floor, which has a nearly double-size bed, a table and a chair.

Szczesny told Friday's news conference that the building achieves two goals: filing an empty city space and linking Warsaw's World War II tragedy, when more than half the city was destroyed, with modern buildings that went up afterward.

A passerby walks past Keret’s House, which is sandwiched between a pre-war house and a modern apartment block in downtown Warsaw. (Alik Keplicz/Associated Press )

The first tenant will move in Saturday: Etgar Keret, an Israeli writer whose ancestors died in Poland during the Holocaust.

"It is a kind of a memorial to my family," said Keret, explaining that his mother's and father's families died in the Holocaust under Nazi Germany's occupation of Poland, and his paternal grandfather died in Warsaw's 1944 uprising against the Nazis.

The structure has been named Keret House after the Israeli writer.

He said he only visits Warsaw twice a year, so other tenants will be able to try out the tight quarters of the non-profit building for free, too.