#Japan #Tokyo #Toolbox #Tadaaki Shimizu #wooden inner sash

New Dimensions in Home Design: The Wooden Inner Sash

On January 15, 2026, TOOLBOX, a company based in Shinjuku, Tokyo, will launch its exciting new product: the wooden inner sash, developed in collaboration with renowned architect Tadaaki Shimizu. This innovative design emphasizes aesthetics, creating a cozy window space that enhances the home environment.

Aesthetic Over Performance: The Concept Behind the Wooden Inner Sash

The wooden inner sash is crafted from high-quality hinoki wood and fits snugly over existing window frames to create a wooden window edge inside the home. Unlike conventional products that prioritize insulation and soundproofing, this design focuses on providing a visual coherence with architectural elements within a space. This dual window concept allows homeowners to modify their interiors beautifully without altering shared external elements, which is often restricted in apartment settings.

Architect Tadaaki Shimizu, who has been instrumental in the development of this product, previously designed bespoke wooden elements for various projects. The unique concept was birthed from TOOLBOX's SPIN-OFF project initiated in 2022, which aims to transform architects' designs into market-ready products. The first phase introduced the ceiling slit fan, designed in tandem with Horibe Associates, successfully integrating a ventilation system seamlessly into kitchen spaces.

Architectural Approach to Window Design

In residential buildings, particularly condominiums, the limitations imposed by collective property management often restrict individual renovations, especially concerning window elements. Generally regarded as fixed components of shared spaces, window frames frequently disrupt the overall aesthetic vision of homeowners. However, architects like Shimizu have been finding creative solutions to enhance the design, allowing homeowners to define their personal space more effectively.

The wooden inner sash serves as an additional layer, creating a distinctive interior environment while acknowledging the existing aluminum frame's presence outside. Shimizu’s design foresight ensures that the sash integrates naturally with the architectural elements, prioritizing a seamless aesthetic over traditional performance metrics.

Impact on the Living Space

The presence of this wooden inner sash not only beautifies the window area but also subtly transforms how residents interact with the space. Furniture arrangement can evolve with the new design, encouraging the use of window sills as functional spaces for seating or decoration. Unlike conventional products, which can emphasize technical specifications, this inner sash fosters an inviting atmosphere, blurring the lines between interior and exterior spaces.

The overall design ensures that while insulation performance is considered, it is not the primary focus. The wooden inner sash has undergone extensive testing, demonstrating effective thermal insulation properties. Utilizing hinoki wood, known for its low thermal conductivity, the sash maintains solid air-tightness through meticulous craftsmanship and attention to detail.

Quality Craftsmanship and Sustainable Design

The careful selection of materials and precision during manufacturing play a crucial role in the wooden inner sash's appeal. With high standards applied to every aspect of production, from material choice to final assembly, these sashes embody a unique blend of design and functionality.

Product Line Overview

The wooden inner sash will be available in various specifications, customizable down to the millimeter, ensuring a perfect fit for varied window designs. Homeowners can choose between clear or mist glass, depending on their desired aesthetic while also accessing options for insect screens. Pricing starts at 121,000 yen for the sash without a frame, with options varying based on size and features.

For full details on product offerings and specifications, visit TOOLBOX's official website. As part of an ongoing mission to enhance living environments, TOOLBOX continues to provide innovative solutions that marry aesthetics with practical living needs.

Conclusion

TOOLBOX's wooden inner sash represents a significant step forward in home design, stressing the importance of aesthetic value in building products. With its strong emphasis on transforming everyday spaces into beautifully designed environments, this product is poised to resonate with homeowners seeking to enhance their living conditions while adhering to the architectural integrity of their homes.