MTKA (Murayama + Kato architecture) has added an inhabitable elliptical void between the roof and and the upper floor of this family house in the city of Kodaira, Tokyo, Japan.

The Japanese studio has renovated the entire interior of the 20-year-old residence, whose most unique features are a large window and a pitched roof facing south.

Located above the common living areas, the supplementary ceiling not only defines the space both above and below it, but it also works as a structural and environmental element, making it possible to remove the existing bracing and let the wind in from the upper part of the large window.

MTKA has inserted the elliptical void structure right below the roof of the house, offering a supplementary surface for the family to occupy.

This additional ceiling has been placed at 1,8 meters above the floor of the upper level, where common living areas such as the kitchen, dining and living rooms are located in one open plan space.

The structure has also made it possible to remove the existing bracing of the large, floor-to-ceiling window that occupies the south wall of the upper level, allowing natural wind to enter the interior.