Anyone who is not yet familiar with contemporary Japanese and especially Tokyo architecture will easily be amazed when getting to know it. Hardly any other building culture is so creative and imaginative enough to close the narrowest gaps between buildings and at the same time create exciting living concepts worth living in the smallest possible space. In this respect, modern Japanese architecture is unbeatable. But despite its wealth of ideas, it still lags far behind in one area: energy efficiency. A government program is to bring about a turning point.
They all have names like “ARROW”, “63.03°”¹, “Little House with a Big Terrace”² or “Promenade House”³ and they all have one thing in common: they are gems of modern Japanese architecture that have caused a sensation in the trade press over the past five years, among other things, because they creatively make the most of a gap in a building that hardly deserves this name. However, they also have one detail in common, which was usually neglected: poor energy efficiency.
From the “waste house”…
Thin, barely or not at all insulated walls, large single-glazed windows and leaking doors are not uncommon even in modern Japanese architecture. In addition, most houses do not have central heating. Instead, their residents use electrical heating or air conditioning with a heating function when needed. In total, this results in higher per capita energy consumption.
… to the zero-energy house
This lax handling of energy is problematic in two respects: Firstly, since the catastrophe at Fukushima, as a result of which electricity generation by nuclear power was almost completely discontinued, Japan has been heavily dependent on imports of gas, coal, and oil. The island state itself only has a dwindling supply of its own raw materials. On the other hand, the high energy consumption runs counter to the requirements of the climate agreement signed by Japan. The latter was decisive for the government finally launching a strategic plan in 2015, which provides for more than half of the houses commissioned by 2020 to be zero-energy houses.
A little different
In figures, this means that an average of 50,000 zero-energy houses is expected to be built annually by 2020. On the whole, these are similar to zero-energy houses in local areas: a combination of good thermal insulation and our own regenerative energy generation. However, there are differences between both points. While in Spain triple glazing would probably be the preferred solution, double-glazed windows are already advanced in Japan. When it comes to energy generation, Japanese zero-energy houses are also using hydrogen fuel cells in addition to the obligatory photovoltaic system. In addition, a home energy management system (HEMS) – a smart home application that monitors and intelligently controls energy consumption – is virtually a standard feature of the technology-savvy Japanese.
Japan has recently lagged not only in terms of building energy efficiency but also in the expansion of renewable energies. This may come as a surprise to the otherwise highly developed country, especially as it was a leader in the development of renewable energies not so long ago. The main culprit is the powerful nuclear lobby or the so-called “nuclear village”, consisting of influential politicians, industrialists, scientists, and the media, which, despite the Fukushima catastrophe, continues to propagate a continuation of the more reliable and thus “safer” nuclear energy. In the meantime, however, not only a large part of the population is calling for a rethink, but also large parts of the industry.
The establishment of zero-energy houses is a good start. And they don’t have to be different from other houses in purely formal terms (apart from the photovoltaic systems). Thus, the grandiose architectural ingenuity of the energy revolution is likely to be preserved. Perhaps the increased requirements of the zero-energy standard will even lead to completely new, sophisticated structural solutions.