Iwami Art Museum in Shimane Arts Centre 'Grand Toit', Masuda, Shimane Prefecture, Japan

This connection to local heritage is manifested most strikingly in the building's exterior: its expansive roof and walls are clad with approximately 280,000 locally crafted Sekishu-gawara tiles. These are highly prized, traditional Japanese roof and wall tiles, fundamental to the Iwami region's cultural identity. Distinct for their durable red hue and glossy, glass-like coating, the tiles are renowned for their weather resistance and unique aesthetic quality—shifting dramatically in colour from shades of red and orange to hints of gold and green, depending on the sun's angle. This dynamic, light-reactive material set a high bar for the interior lighting design, which needed to support a similarly organic and changing environment.

The centre functions as a dual-purpose institution, housing the Iwami Art Museum and the Iwami Arts Theatre. The primary architectural concept for the entire complex was a conscious integration of natural light wherever structurally possible. The architect deliberately utilised side windows and skylights throughout the museum, creating an interior atmosphere that organically shifts throughout the day. Consequently, ERCO—known for its museum-grade quality and precision—was chosen for the critical areas of the Exhibition Halls and main Foyer, where controlled, high-quality, and supplemental accent illumination is non-negotiable for art conservation and flexible display.

The lighting challenge: preserving quality, gaining efficiency

The museum's original installation relied on ERCO Eclipse QT-12 halogen spotlights. While these offered excellent light quality and precision, the halogen technology was inherently high in energy consumption, generated heat harmful to sensitive artefacts, and required high maintenance. The transition to LED was essential for sustainability and conservation. The challenge for the refurbishment was to replace the warmth and precision of the original ERCO halogen spotlights with LED technology that could maintain the same quality and control required for museum-grade accent lighting, all while seamlessly complementing the architect's primary reliance on natural light.

ERCO’s LED relighting solution: The Optec System

The Shimane Arts Centre chose the high-performance ERCO Optec LED spotlight range for the relighting project, utilising existing track infrastructure. This choice ensured a modern, energy-efficient solution that upheld the high standards of light quality necessary for art display.

Exhibition halls (A, B, C, D): precision and adaptability as daylight supplement

The core function of the ERCO lighting is to provide flexible, accent-focused illumination that steps in to supplement, balance, or override the incoming natural light, particularly on cloudy days or in the evening.

- Case in point: Izumi Kato, Road to Somebody
The museum’s capacity for diverse exhibitions, such as the major retrospective of local artist Izumi Kato (featuring more than 200 works from paintings to sculptures), is fully supported by the Optec system.

- luminaires Used: Optec LED spotlights in various outputs (4W, 8W, 12W, 24W).

- optics: The versatile spherolit lens system offers a range of light distributions: narrow spot, spot, flood, oval flood, and wallwash. This flexibility is paramount for showcasing Kato's diverse practice.

- high-ceiling control: In exhibition hall C, where a closable skylight provides ample daylight and ceilings soar above 7m, the higher-wattage Optec fixtures with narrow spot optics are used to achieve powerful, precise accenting from a great distance.

- conservation: The LEDs' lack of harmful UV/IR radiation and minimal heat generation are crucial for preserving delicate collections.

Museum foyer/entrance: a controlled welcome

The Optec LED luminaires are strategically employed in the foyer to highlight key architectural details, information counters, and circulation areas. This accent lighting acts as a smooth, welcoming transition from the bright, dynamic exterior light to the controlled atmosphere of the galleries.

Conclusion: future-proofing culture with light

The seamless integration of the ERCO Optec LED system represents a major step in the Shimane Arts Centre's long-term operational strategy. By executing a respectful relighting that utilises the best of modern LED technology, the museum has:

- honoured architectural intent: Maintained the precise, accent-oriented lighting approach that was designed to complement the pervasive natural light.

- achieved operational efficiency: Drastically cut energy consumption and maintenance, demonstrating a commitment to sustainability.

- ensured curatorial flexibility: Provided curators with a versatile, future-proof system that can adapt instantly to any exhibition content, guaranteeing that the art is always presented with world-class light quality.

The ERCO Optec spotlights thus serve as the unseen technical force that allows the culturally sensitive architecture of Hiroshi Naito and the legacy of the Sekishu-gawara tiles to shine, ultimately focusing attention on the art and culture within.