Japanese architecture studio SPACESPACE have recently completed this unusual house - the Ground and Above Roof House - which makes clever use of a very particular site.

Built on a corner plot, located one lot behind the main street, the house site borders the streets on the north and the east, a T-junction, and an open car park on a culvert.

According to SPACESPACE, this is an area which has a peculiar atmosphere of openness, one where; "...signboards and pot plants stick out into the street and there are many long-term residents, who are often seen chatting on the street."

Also, the house site is special as there is a change in the zoning near the border of the neighbouring house site, which enables the house to be built slightly higher than the house next door to the south.

The house itself is on two storeys and built in wood, with only a hall and a hill on the first floor which leads to the street. The second floor has been swept upwards a good distance from the busy street with the roof lifted higher than the neighbouring ones which enables the first floor to receive enough sunlight.

In winter, the kamakura-shaped 'hill' with a bathroom inside can store solar heat gathered through a large window located upper south part on the first floor.

It can also be used as a sofa when facing a TV, a veranda when sitting from the outside with a window open, a screen from the entrance, a storehouse and a play place for children.

The bedrooms on the second floor have been kept to a minimum in size so the hall can be used for activities such as study or reading.

From the second floor window, a roof top view opens up.

SPACESPACE's design is not only a clever use of space, but also a clever use of natural resources. In winter, sunlight can be collected from the large windows located under the slab of the second floor and upper south part on the first floor. These are designed for receiving sunlight and solar heat is stored in the concrete hill.

The position of slabs and the height of the hill is "...determined with reference to the sun's altitude in its lowest season, and the eaves location of the next door house." according to the studio.

Floor heating is installed on the concrete hill and the flat area to prepare for days not suitable for heat storage or for the area where the sun isn't shining.

In summer, the sunlight and the heat are shut up by an electric blind and the heat is stored between windows - released from the roof through the slit on the second floor and from the upper part of the second floor window through ventilation space acquired by installing double wall in the north and south.

In winter, this same ventilation space can be used as heat storage and provides warmth through an air inlet.