Located in Rokkakubashi, a famous shopping street of Yokohama, Hakuraku House is the renovation of a 90 year-old two-storey wooden house.
When it was built in the 1930s, the dwelling presented as a symmetrical two-apartment construction. Later expansions added some new rooms that ruined the neatness of the floorplan and complicated the circulation of both levels up.
The project aimed at restoring its original harmony by annexing its extensions with an eye on the flow of the spaces.
Project Name: Hakuraku House
Studio Name: Roovice
Japanese traditional architecture was meant to design buildings easy to disassemble and repair: this method is called Bunkai dekiru (分解できる) which literally translates to “can be disassembled”. This lasted up until the second postwar period, when Japan changed the approach for a quicker and cheaper western-style construction: this followed the need of rebuilding the country in a short time with the lowest budget available.
Despite the change to a more modern architecture, Bunkai dekiru hasn’t been forgotten and is still influencing today’s designs. Its consequent ideas, in particular, helped the research for a variable architecture (Kahen-sei 可変性): one of its subordinate method is called Kakekae (掛け替え, lit. “substitute, replacement” but with a wider variety of meanings) and is the approach of altering the given elements to increase the quality of the whole space around.
Kakekae has been the starting point of the renovation project for Hakuraku House, and it is mostly visible in the first-floor circulation system: as mentioned earlier, the floorplan was designed mirrored on the central axes with later extensions on the north side. The latter one added an isolated bedroom on the second-floor corner, needing a third staircase to reach it in addition to the twisted and steep symmetrical two that shaped the plan. That created an unclear and uncomfortable situation since the new stair is more comfortable to climb but completely spoiled the flow in the ground floor.
Here is where Kakekae saved the design by joining the pros and discarding the cons: the added stair shifted and replaced one of the primitive one and so restored the symmetrical circulation, giving at the same time more space to the kitchen. The void left in the extension’s slab became a double height to connect the kitchen and the vanity unit obtained from the added bedroom above. Next, the shower room moved from the first floor to the annexe space.
The second level removed its division walls to generate an open space with plenty of natural light entering from the new windows.
A usual task occurring during old buildings renovations in Japan is the seismic retrofitting meant to update obsolete structures. These have to be bonded together to better bear the vibrations of an earthquake. For Hakuraku House, the retrofitting is achieved by dampers attached to every structural element. Besides being remarkably affordable, this keeps the layout open and flexible since it doesn’t require new columns or beams to be installed.
Since the renovation affected only the interiors, the house from outside comes directly from a past age, thanks to the visible faded wood and rusty parts.
On the inside though, a strong duality between the compact first floor and the open second one is strengthened by the steepness of the stairs.
Despite contemporary Japanese architecture following the “dismantle and reconstruct” method, Bunkai dekiru is still arguably one of the most relevant theories today. In fact, it allows young generations of architects and workers to acknowledge the traditional construction systems, and it also deals with sustainability and recycling of spaces and building materials.