What's With All Those Crazy Houses in Japan?

Small House in Tokyo by Sejima.

If you're the type who regularly visits architecture blogs you're probably aware of the seemingly endless stream of whimsical homes coming out of Japan. They tend to be compact; modern; stark; and often defy safety/code, and unlike the US the primary clients are middle class. So what's the deal? Why are people in Japan so willing to give architects such a free hand?

House in Yamasaki by Tato Architects.

In Japan wooden homes are depreciated over a 20 year period and on average are demolished after just 30 years. The whole list can be found here; steel reinforced concrete building have the longest depreciation at 47 years. 87% of home sales in Japan are new homes compared to 11-34% in most western countries. This costs Japan about 4% of it's GDP annually, so why do they do it?

After WWII there was a shortage of housing in Japan and the world in general that led to the construction of many poorly and cheaply built homes*. As they aged it was simpler to tear them down than it was to rehab them. At the same time land prices skyrocketed. When the value of land goes up the type of building that can justifiably be built on a site changes - more homes were razed. In the 1980's an asset bubble in land prices brought  government controls and rules regarding the steep depreciation of buildings**. All of this culminated in the current system of essentially disposable homes.

So how does this lead to such experimentation? Taking risks with the design can be a bad investment in the US because banks will rarely finance the construction of a radical design. Since most homes are purchased through a mortgage, the bank owns the home and they won't approve something they can't readily sell. Almost no one buys a "used" home in Japan so the homeowner and architect can design whatever they want. It doesn't affect the bank since they can't resell it anyways. Hence...

Also worth checking out is how these homes are built - largely automated gigantic CNC mills run by CAD/CAM.

Long Tall House by SPACESPACE. Notice the lack of railing.

As wasteful as this practice may sound to a westerner it's just normal in Japan. It makes one wonder which of our norms may be just as arbitrary. 

* Most of this info is from this Arch Daily article.

** Japan's Lost Decade, yes that's facile but if you're interested Paul Krugman wrote a great book about it called The Return of Depression Economics).