Giving eternal light to a box that disappears in 30 years: A dialogue between an atrium and louvers that weave 'shadows' like a Morandi still life

It is said that the average lifespan of a Japanese house is only 30 years. Compared to approximately 80 years in the UK and 65 years in the US, our homes have been treated as surprisingly short-lived 'consumer goods.' However, in 2026, what we should be questioning is not just the 'physical durability of the building,' but the 'quality of time' spent in that space itself.

Hello, I am Jin Kawazoe. While working between Kagawa and Tokyo, I ask myself every day, 'Why is this form necessary?' Today, I would like to talk about the 'light and shadow' devices—louvers and atriums—that are indispensable in my designs, from a perspective closer to art.

Why have our homes become so 'flat'?

Traditional Japanese houses used to have deep eaves and verandas, where a rich 'dimness' existed. It is an aesthetic that dwells in the darkness, as Junichiro Tanizaki explained in 'In Praise of Shadows.' However, modern urban housing tends to become a 'homogeneous white box' with the same brightness everywhere, all in the pursuit of efficiency and light.

A homogeneous space may seem convenient at first glance, but it bores the human senses. The cold light of morning, the drowsy shadows of the afternoon. It is only when these fall into a space that we can truly feel that we are living in 'this very moment.' What I aim for in my design is a space like a still life by Giorgio Morandi. Just as the bottles and vessels placed on a table quietly assert their presence through subtle gradations of light, I believe that a house should also have a sculptural depth through the shifting of light.

Louvers that 'weave' light, atriums that 'frame' the sky

So, how exactly do we create that 'depth'? That is where louvers and atriums come in.

To me, a louver (lattice) is a 'light filter.' Instead of letting direct sunlight in as it is, it blocks it, cuts it into fine pieces, and guides it into the room. It brings a certain rhythm to the space, as if Erik Satie's 'Gymnopédies' were quietly vibrating the air. It blocks the view from the outside while allowing only wind and light to pass through. This 'ambiguity of boundaries' is the true nature of openness in an urban setting.

On the other hand, an atrium is a 'vertical breath.' In densely populated urban areas, even if you open windows horizontally, you often only see the walls of neighboring houses. If so, release your gaze toward the sky. When the light pouring down from above passes through the louvers and casts long shadows on the first-floor floor, the house transforms from a mere 'box for sleeping' into an 'observatory' that reflects the seasons.

[Honest Q&A] An architect answers the 'curiosities' of readers

I will answer, without sugarcoating, the real questions about light and shadow design sent by my note followers.

Q1. I hear that if you build an atrium, it gets cold in the winter. Is that true?

A. That is correct for old houses with low insulation performance, but it is different now. Rather, an atrium functions as a 'heat circulation path.' Assuming high insulation and high airtightness, if you move the air with a ceiling fan, you can minimize the temperature difference throughout the house. In the 'House Design' I propose, I perform simulations of this thermal environment logically to achieve both 'openness and warmth.'

Q2. Louvers seem like a pain to clean. How should I think about maintenance?

A. Certainly, horizontal louvers tend to accumulate dust. Therefore, I often use 'vertical louvers' or select materials that are easy to maintain (aluminum or highly durable artificial wood). Also, I do not force their installation in places that are out of reach, but rather design by narrowing down the points where the effect of light can be maximized. How to land the trade-off between 'beauty and effort' is where an architect's skill comes into play.

Q3. Is an atrium effective even in a small house? I feel like the floor area is a waste...

A. It is the opposite. 'Small houses are exactly where an atrium is needed.' Rather than prioritizing the 'number' of floor area and keeping the ceiling low, expanding the experiential 'volume' leads to an overwhelmingly richer life. In a project I was in charge of before, as a result of providing vertical expansion as seen in the 'Construction Achievements,' the client told me that they 'feel more freedom than the actual size.'

Living in the 'art' of architecture

In a case of 'Kagawa Residential Design' that I worked on previously (a house inspired by a private resort), I installed a water basin under the atrium. Light passes through the louvers, reflects off the water surface, and the ripples are projected onto the white ceiling. That scene was no longer just architecture, but closer to installation art.

My job as an architect is not simply to build 'sturdy walls.' It is to design 'mental margins' where the people living there can look up at the sky in a fleeting moment or stop in their tracks at the beauty of shadows falling on a wall. Whether it is large-scale architecture like Sony City, which I was involved in during my time at Plannetec, or current private residences, the underlying logic is the same: to get to the bottom of 'why that light is necessary.'

Summary: What kind of shadows do you want to cast on your life?

If Japanese homes are destined to be demolished in 30 years, it is far too wasteful to let those 30 years end in 'mere consumption.' Weaving light and taming shadows—such a home harbors an 'emotional durability' that grows more endearing as time passes.

If you feel a sense of 'confinement' or 'flatness' in your current home, why not reconsider the volume of your space from the perspective of building a home without regrets? The way light enters can change your daily life dramatically.

At our studio, both in Tokyo and Kagawa, we value this dialogue regarding 'light design.' Whether you have specific concerns or your vision is not yet set, please start by contacting us and let us hear about your ideal 'light'.

Architecture is like a screen that projects the drama of your life. We would be honored to help color your story with the perfect lighting.