At Kaltimber, sustainability isn’t just about reclaimed wood — it’s about the choices we make with every board, every beam, and every cut. Our reclaimed Ulin, also known as Borneo ironwood, is a rare material with extraordinary durability. Giving it a second life as decking or flooring is only the beginning of its story. The way we handle even the smallest offcuts is proof of our deep commitment to responsible design and zero waste.
This philosophy extends beyond Kaltimber’s own production. Thanks to our sister company, Naturanexa, pieces of wood that would otherwise be impossible to use in decking and flooring find a new purpose. The result is a product that has become essential in contemporary tropical architecture: kisi-kisi. Through this partnership, what starts as a byproduct becomes a star material, enriching homes, villas, and public spaces across Indonesia and beyond.
How Decking and Flooring Create Offcuts
Producing reclaimed wood decking and flooring requires precision. Boards must be cut to exact widths, ensuring perfect alignment and finish. To achieve this, we use a specialized machine that trims the sides of each board to standard dimensions.
While this process guarantees quality decking and flooring, it also produces long, slim offcuts. These pieces have the same strength and weather resistance as the main boards, but their dimensions make them unsuitable for Kaltimber’s products. For most companies, such side pieces would be discarded. At Kaltimber, we see them as an opportunity waiting to be shaped.
From Offcuts to Kisi-Kisi
This is where Naturanexa steps in. With an eye for design and architectural function, Naturanexa transforms these offcuts into kisi-kisi — wooden slats that can be used as louvers, partitions, shading elements, or decorative wall features.
Kisi-kisi is increasingly valued in modern tropical design. It allows for airflow while maintaining privacy, softens natural light, and adds a warm, textured finish to interiors and exteriors alike. Whether framing a façade, dividing a room, or forming part of a pergola, kisi-kisi demonstrates how reclaimed ironwood can continue to surprise with its versatility.
By turning what was once a limitation into a celebrated product, Naturanexa helps extend the life cycle of reclaimed Ulin while offering architects and designers a flexible solution with timeless appeal.
Benefits of Kisi-Kisi in Design
Kisi-kisi is not only practical but also deeply aesthetic. It has become a favored element in tropical architecture for several reasons:
Ventilation – Its slim slats let air flow naturally, reducing heat and keeping interiors cool.
Light Control – Kisi-kisi filters sunlight, creating soft patterns of shade while protecting from glare.
Privacy – It allows a sense of enclosure without blocking openness or views.
Natural Warmth – The rich tones of reclaimed ironwood bring depth and texture to any design.
From modern villas in Bali to resorts across Indonesia, kisi-kisi has become a hallmark of thoughtful, climate-responsive architecture. And because these slats come from reclaimed wood offcuts, each one also carries the story of renewal.
Zero Waste as a Guiding Value
Every board of ironwood that enters our yard has a story — salvaged from old jetties, bridges, and traditional houses in Kalimantan. Out of respect for this rare material, our mission is not only to reclaim it but also to ensure nothing goes to waste. The transformation of decking and flooring offcuts into kisi-kisi reflects this value in action.
Working hand in hand with Naturanexa, we move closer to our 0 waste goal, giving second life to even the slimmest of salvaged pieces. This approach proves that sustainability is not a label — it is a practice, embedded in every stage of production, from raw material to final design element.
In the end, decking, flooring, and kisi-kisi are all part of one cycle. A cycle where reclaimed ironwood continues to live, to serve, and to inspire.