Panels constructed with composite metal technology decorate facade of a new London hotel.
The Dorchester Collection’s 45 Park Lane hotel will soon open to guests in London’s Mayfair district following a renovation of the building led by The Office of Thierry Despont. The architect has transformed the building’s exterior with metal fins spanning the width of seven of nine floors, emphasizing the hotel’s curved shape and shielding its guest spaces from sun. All new or highly renovated buildings in the district must include a public artwork component, and Despont considered a series of repoussé copper panels on the hotel’s west side, which faces Hyde Park. Intrigued by Brooklyn-based Situ Studio’s digital modeling capabilities, he asked the firm to develop a gradient overlay for the panels in Photoshop, then translate it into Rhino. But once the design was put out to bid the cost of creating the panels proved prohibitive, so the team went back to the drawing board to explore other options.
Process CNC milling, cold-sprayed composite metal coating
Situ began researching alternative materials for the facade panels and came across a California-based company called LuminOre that uses a patented cold-spray technology to apply metal composite to a surface. “We got samples and the architects were excited about this approach,” said Wes Rozen, one of Situ’s partners. “It’s a resin that has metal particles in it, and it becomes what can be defined chemically as metal.”
Panel fabrication at LuminOre's facility (Situ)
Because the LuminOre application process is cold, the material can be applied to almost any lightweight substrate or core material, from foam and cardboard to concrete, without compromising its shape. The LuminOre composite can be sprayed on using the company’s automated application system or cast into a form. It contains up to 95 percent metal, so the finished product can be sandblasted, acid brushed, or given a hot patina wash like forged metal. The material can withstand 2,364 psi without separating from its substrate, according to the company’s tests.
Using the design team’s digital files, LuminOre fabricated a full-scale mockup of one facade panel. Composed of a CNC-milled #2 EPS foam substrate coated in a polyurethane resin hardcoat and finished in LuminOre White Bronze, the piece was sent to London for public hearings about the project and eventually approved. LuminOre fabricated the 24 finished panels at its Carlsbad, CA, headquarters. Though the White Bronze finish naturally resists patina, the panels were coated in a final ceramic clear coat to further slow the aging process.
The panels weigh approximately 9 pounds per square foot, significantly less than traditional metal panels. Project engineer WSP Flack + Kurtz approved attachment of the panels’ fiber-reinforced plastic frame to a steel fitting tied back into the building’s main floor slab. First-floor panels are almost 10 feet tall, while those on the balconies above are about 6 ½ feet tall. Each panel row consists of two 5-foot-wide panels on either side of a nearly 9-foot-wide center panel.
When the hotel opens in September, the metal sculpture will augment Despont’s theme of geometry and light throughout the building. For Situ, a newfound understanding of LuminOre’s capabilities will likely influence future projects. “With CNC technology being able to produce all sorts of articulated surfaces, having this available for outdoor finishes opens up our thinking about surface treatments,” said Rozen.
The Dorchester Hotel’s new facade art panels (Situ)
The hotel at 45 Park Lane (Situ)
Panel fabrication at LuminOre’s facility (Situ)
CNC-milled foam substrate for the art panels (Situ)