Terrace Housing – Why is it uncommon in Japan?

Western visitors are often struck by the density Tokyo’s small houses. Often a gap of only 40 centimeters (15″) separates two houses – barely wide enough for a person to squeeze between. Windows often look into these dark gloomy voids. Seeing this depressing site throughout Japan’s towns and cities leaves me to wonder: why haven’t the Japanese built more terrace housing?

Terraced Housing
Terrace houses (townhouses or row houses in the US) are conjoined by a common “party” wall. They are as old as cities themselves. The typology reached its peak in Georgian cities like Bath where architect John Nash laid row after row of continuous housing. Terrace houses fell out of favor in 1920s as the wealthy fled polluted and congested industrial cities to live in detached homes in the suburbs. Now terrace housing is enjoying a renaissance throughout Europe and the US as developers, architects, and community planners recognize it has many benefits.

Better Communities

The high density of terrace housing is one such asset. It engenders community and creates safer streets. Rear gardens can only be accessed through the house and continuous facades overlook roads from opposite sides. In Japan, planning regulations limit the proportion of developable land to the overall area of each plot. Terraced housing could consolidate that scant spare land in a private garden (something Japanese homes often lack space for), rather than leaving a wasteful no man’s land between adjacent plots.

In Japan, town-planning guidelines are fairly ineffective. It is not uncommon to see a new home built right next to an existing one, cutting off sunlight and creating windows that look right into one another (look what recently happed to our building!). As terraced houses share the same aspect, overlooking and blocked access to light are not inherent problems.

Cost and Energy Efficient Homes
Terracing has tremendous sustainable advantages too. Houses tend to be longer in plan. With each house snugly nestled between its adjacent neighbors, the homes buffer and insulate one another (effectively sharing heat during winter). Developers also like terraced housing since the party walls cost less to build (no external cladding or windows) and they can be built more densely and efficiently.

The Machiya
Japan should not overlook its own tradition of terraced housing. Machiyas (literally meaning town house) are long timber buildings with narrow street frontages. The ground floor was typically a craftsman’s shop with living quarters above. Many contain internal courtyards, bringing daylight into the middle of their deep floor plans. Although these beautiful old homes can still be seen in preserved areas like in Kyoto’s Gion, they have been demolished at a rapid rate. A preservation movement is underway to save the few remaining examples. Some have been restored as shops and B&Bs, but for most it is too late.

Japanese homebuilders continue to demolish existing houses at a high rate, replacing them with closely packed clusters of detached homes. Ironically, building terrace homes could be more profitable for the developers, but I suspect that their target market sees a detached home as more desirable (and possibly more private?). Terrace housing does not lend itself well to this style of scrap-and-build development. There also may be legitimate concerns related to the spread of fire and earthquake integrity, but modern construction can mitigate such risks.

To improve Japan’s communities and the quality of the building stock in general will take a sea change in urban planning policy, building economics, and market sophistication. However, this is exactly what has already happened throughout the US and Europe. I hope that we can teach Japan well-designed terraced housing not only creates greener, safer and more efficient communities — it creates homes worth preserving.

(A Few MORE Things About Housing)