Wood knotholes are typically a sign of poverty in Japanese architecture, but ICADA has used them to create a unique lighting effect in Knothole House.

木結構通常是日本建築中貧窮的標誌,但ICADA使用它們在Knothole House中創造出獨特的照明效果。

ICADA founders Masaaki Iwamoto and Nariaki Chigusa wanted to show that “poor is more” with this small wooden house.

They used knotholes – typically found in cheap wood – to create tiny skylights all across the roof of the modest building.

ICADA創始人Masaaki Iwamoto和Nariaki Chigusa希望通過這個小木屋表明“窮人更多”。

他們使用knotholes–通常在廉價木材中找到 – 在整個建築物的屋頂上創造出微小的天窗。

“Light comes into the house through the numerous knotholes, like a starry sky,” said the architects.

“Although knotholes are the symbol of poverty in Japanese timber building tradition, in this case they offer a rich spatial experience. We believe this is an example of ‘poor is more’,” they stated.



Knothole House is a simple, 90-square-metre property located in a seaside town in Hiroshima prefecture.

It provides an annex to the home of a painter and his wife, giving them extra living space that can be easily opened up to the elements, taking advantage of the sea breeze.

Knothole House酒店是一棟90平方米的簡約酒店,位於廣島縣的海濱小鎮。


The house is divided up into a row of four rooms with varying levels of privacy: a kitchen, a living room, a garage and a workshop, all sheltered below a simple pitched roof.

There is also a small bathroom in one corner.



The knothole skylights puncture two-thirds of this roof, but an outer skin of translucent polycarbonate ensures that rain doesn’t come in through them.

The rest of the roof is covered with steel panels, to meet fire protection regulations.



Materials were chosen to keep the cost below $800, or £630, per square metre. The wooden panels containing the knotholes are laminated timber – a product created during production process for cross-laminated timber (CLT).

選擇材料使成本保持在每平方米800美元或630英鎊以下。 包含結構的木板是層壓木材 – 在交叉層壓木材(CLT)的生產過程中產生的產品。

“Compared to CLT, this semi-finished product is much cheaper,” said Iwamoto and Chigusathe.


Instead of using wooden beams to support the lightweight roof, hemp ropes were installed. They are slotted through through the knotholes.

“As tension material, hemp ropes are cheaper than steel cables, and they imply the character of the site as fisherman’s village,” said the architects.

不使用木樑支撐輕質屋頂,而是安裝了麻繩。 它們通過knotholes穿過。


The external walls of the building are a mixture of wooden panels, left over from the roof, and insulation-filled textile. There are no internal coverings, so the wooden framework and services are left on view.

Concrete slabs provide a utilitarian floor in all the rooms except the garage, which has no flooring surface.

建築物的外牆是木板的混合物,從屋頂上留下,以及填充絕緣材料的紡織品。 沒有內部覆蓋物,所以木製框架和服務留在視野中。


Furnishing is kept simple inside the house, allowing the wooden walls and ceiling to dominate the space.

Lighting is strung around the hemp ropes, meaning they can be easily moved around.



Masaaki Iwamoto was a partner at Vietnamese firm Vo Trong Nghia Architects before setting up ICADA in 2015 with Chigusa. His past projects include House in Nha Trang and Farming Kindergarten.

Masaaki Iwamoto是越南公司Vo Trong Nghia Architects的合夥人,之後於2015年與Chigusa建立了ICADA。 他過去的項目包括芽莊的House和農場幼兒園。

Project credits:

Architecture firm: ICADA
Principal architects: Masaaki Iwamoto, Nariaki Chigusa
Structural engineer: Mika Araki
Contractor: Mimachi Komuten


首席建築師:Masaaki Iwamoto,Nariaki Chigusa
結構工程師:Mika Araki
承包商:Mimachi Komuten



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