Meixi Urban Helix, China

23rd October 2018

Merging the natural elements of water with the urban development, the Meixi Urban Helix is a beautiful new structure, uniting the two worlds of nature and man-made constructions.

Located in the southwest of Changsha, China, this new urban axis, designed by German architects KSP Jürgen Engel Architekten, is a multi-functional public space where visitors can enjoy panoramic views of Lake Meixi, as well as the planned city expansion that it overlooks.

The structure ascends above a man-made plateau on the lake, spiralling to a height of 34 metres through an exposed ramp measuring six to eight metres wide. The interior of the helix provides visitors with a reversing path ramp leading from the structure’s highest point down to the new urban area.

Lighting for this impressive structure comes courtesy of New York-based lighting designers Office for Visual Interaction (OVI). By combining few directly visible lighting elements with a backdrop of indirectly illuminated architectural finishes and surfaces, OVI has created a consistent, balanced lighting scheme spanning the structure.

OVI regularly collaborate with architects and design teams very early in the design process, maintaining a regular dialogue as the project develops. This project was no different, as OVI worked with KSP Jürgen Engel Architekten from the competition stage of the project. Because of this, OVI was able to develop a strong lighting concept that remained consistent as the project progressed.

Markus Fuerderer, Project Lead and Product Design at OVI, explained: “We extracted the essence of the architecture to generate a well-conceived lighting design scheme.

“For Meixi Urban Helix, we envisioned an iconic gesture for the exterior nighttime identity with a continuous, flowing band of radiant light that creates a visual connectivity of the double-helix ramp and connecting bridge. To intensify this infinite metaphor, we kept all structural elements, such as the radiant vertical helix columns and the undulating wave structure of the bridge, dark in contrast.”

In order to effectively articulate the project as a flowing, infinite band of light, OVI sought to increase this character further by continuously up-lighting the helix ramp and bridge surfaces consistently. Colour capability was also included as a means of visually separating layers of the outer ramp surfaces from inner surfaces, creating visual clarity and added depth.

For the nighttime identity of this iconic new structure, concealed linear LED uplight coves illuminate the ramp undersides at night to articulate a continuous, spiralling ribbon of light. To increase visual depth, RGBW capable luminaires have been specified, allowing to distinguish the outer ramp surface from the inner surface by adjusting the light colour.

Elsewhere, handrail-integrated linear LED luminaires provide additional illumination for bridge and ramp areas to guide visitors through the ascending and descending paths, connecting between the structure and the new urban area.

While these lighting fixtures help to enhance the nighttime identity of the structure, OVI was keen to reduce the perceived amount of illumination for visitors to enhance the spectacular panoramic nighttime views. Fuerderer continued: “We designed a low-mounted guiding element of sparkle using miniature marker lights along the inner ramp perimeter that light the walkway and intuitively guide visitors up and down the helix.”

Situated on an artificial island with an area of about 20,000sqm, radiant in-grade lines of light correspond with the paving pattern that originates at the centre of the helix’s geometry. Zooming in, concealed step lights and under bench lighting details accentuate the stage and steps, while miniature in-grade LED uplights at the base of each vertical structural beam illuminate the edge of the vertical elements. This serves to generate a subtle visual framework for the spiralling ribbon, complementing the fluidity of the design and contrasting it against the nighttime backdrop of the city.

One of the most remarkable things about the Meixi Urban Helix is the consistent, uniform lighting across its span. This, according to Fuerderer, is an integral part of the structure’s design. “A key feature of the lighting gesture is the continuous appearance of the illuminated, flowing, infinite band of light along the bridge and helix,” he said.

“We designed a miniature linear cove detail at the bottom edge of the sectional profile. This cove accommodates a high performance linear wash luminaire with optimised optics by Electrix Illumination to generate a soft light gradient across the entire ramp overhang, reaching up to eight metres in distance.

“An important visual aspect of this detail is the shielding: the cove detail is dimensioned to avoid direct views into the light source, while maintaining the architectural integrity of the design.”

OVI’s overriding approach to lighting design, across an extensive portfolio that has seen it work with the likes of Zaha Hadid Architects, Foster + Partners and Grimshaw, is to “reinforce the architectural features and give life to a project ‘after dark’”.

And Fuerderer believes that this philosophy has been met again with the Meixi Urban Helix. “The lighting design should be a natural extension of the architectural language and we feel that is the case here.

“There are so many visitors at night that we hope we have given them the opportunity to experience a magical moment when they visit this unique place.”

Pic: Ines Leong