Charred cedar clads the walls of this house in Aichi, Japan, by architecture studio MDS, while exposed wooden beams create a rack-like effect on the underside of the diagonally slanted roof.

Like many houses owned by young families in Japan, Okazaki House was built on the same site as the residence of the client's parents.

Tokyo-based studio MDS used a traditional charring technique known as Yakisugi to blacken the cedar planks used for the building's exterior, helping to protect the building from decay.

The site naturally slopes down from one side to the other, so the architects created a single-storey dwelling containing a series of tiered levels.

An entrance leads into the house at the uppermost level, where the living room is located. The floor then steps down to create a dining room in the middle and a kitchen at the lowest level.

"This enables people to maintain the same level of eyesight, and retains an exquisite sense of distance," said the architects, explaining how they wanted to maintain an open-plan atmosphere.

Pendant lamps hang down from between the ceiling beams to illuminate worktops and seating areas, while a piece of built-in furniture provides shelving and a desk.

A small courtyard with a tree at its centre cuts into the volume of the building, separating living spaces from the master bedroom.

A second bedroom and bathroom are tucked away on one side and residents have to step down again to access them.

Polished oak floorboards run throughout the house, while latticed wooden screens can be used to partition spaces when required.

Photography is by Forward Stroke Inc.

Here's a project description from the architects:

Okazaki House

The generation gap has become a problem in Japan in recent years. There are an increasing number of two-family homes, as well as houses built on the lots of parents' houses. This house is one of the latter. Although the residents are parents and child, solicitude should be expressed with this not-so-large site.

This house is a one-storey building with a shed roof, which lowers the roof height on the side of the parents’ house, resulting in wide views maintained with open sky from the parents' house.

For the interior space, the shape of the large shed roof is directly exposed, and two angled walls (canted walls) are placed in this open-space. This simple design creates various interior spaces in both plan and cross-section. The floor levels of the rooms are decided based on the ground height around the building, and are planned to utilise the height differences.

The site is sloped from north to south, and the west side, where the parents' house stands, is lower. The main bedroom is located at the highest part of the site, the north-east side; across from a central courtyard, the level gradually slopes towards the south, from the living room, to the dining room and to the kitchen. This enables people to maintain the same level of eyesight, and retains an exquisite sense of distance.

For the framework of the roof, standard cedar lumber of 120x120mm, which is commonly sold on the market, is used. Instead of using custom sizes or laminated wood, the lumber is alternately laid over the beams within the maximum standard length of 6m, and is crisscrossed at the upper part of the canted walls that roughly divide the interior. This creates an impressive ceiling surface as well as functioning as the roof framework.

Company name: MDS Co.Ltd
Architecture: Kiyotoshi Mori & Natsuko Kawamura / MDS
Location: Okazaki-City, Aichi
Principal Use: residence

Structure: wood
Site Area: 213.74 sqm
Total Floor Area: 98.17 sqm /1F
Exterior finish: yakisugi / cedar forms exposed concrete
Roof: galvanised colour steel sheet standing-seam roofing
Floor: oak flooring
Wall: plasterer
Ceiling: oregon pine of 120 x 120 mm