The project explores the renovation and expansion of a family house with an extension in cramped conditions on a 7 m wide plot with a significant northern slope. The aim of the project was to divide the house into two residential units and one non-residential unit - a studio. There is a one-bedroom apartment of 47 m2, three-bedroom duplex of 89 m2 and a two-bedroom duplex of 68 m2. Everything was designed with the aim of effective use of the narrow plot in the form of vertically arranged units - duplexes and ensuring the best possible energy efficiency.

The original brick family house with wooden beam ceilings and a hipped roof included two units without sanitary facilities, which were located in the yard in the outbuilding. The building was completely cleaned to the supporting structure including the roof. The extension to the yard with a flat roof was build with two structural systems: the ground floor on a slope in the form of concrete formwork and ceramic blocks, the first floor (and part of the ground floor) as a wooden structure. Ceilings in the form of wooden beams, foundations in the form of concrete strips. Insulation of the outer shell with mineral wool (brick and wooden structure), insulation of the hipped roof with wood fiber panels (above-rafter insulation) + mineral wool (between-rafter insulation). Facade windows are plastic with triple glazing, roof windows are wooden with triple glazing. Heating is provided by a gas condensing boiler, domestic water heating is by solar collectors, and air exchange is controlled by recuperation units. The building is equipped with a green roof that helps regulate the building's climate. The building is in category B.