Kings Cross Square on the front of Lighting Journal

A very comprehensive feature on the King's Cross Square public realm scheme in this months Lighting Journal.

Details below -

Tim Downey outlines StudioFractal’s lighting design for King’s Cross Square, the first all-LED scheme for a major public space in the UK

The busiest transport interchange in London, serving around 140000 people a day. Kings Cross Square is a gateway to the massive regeneration of the Kings Cross area. The aim of the squares redevelopment was to restore its original integrity and give it a greater civic importance, comparable to that of other public realms in the city such as Trafalgar Square, Leicester Square and Tower Hill Square.

There have been major structural changes to the space. Architect Stanton Williams replanned the station entries and exits to ease movement, and incorporated three large London Underground services structures within the square. Clad in the same granite as the plaza, these merge with the surrounding urban landscape and incorporate a variety of service functions and retail activities, enlivening and animating the square.

Lighting was designed from the outset to create a strong visual identity, support wayfinding and encourage commuters to linger and appreciate the space. The area had to be highly flexible, which entailed achieving the right balance between functional and aesthetic lighting. It had to be easy to use when people were in a hurry — most are on their way to a mainline or underground station — but also a great place to pause and enjoy the surroundings.

The strategy concentrated on incorporating lighting into the built environment wherever possible, highlighting the historic facade to create a three-dimensional space and emphasising materials and textures. The warm brick façade and the grey-toned granite were lit in different colour temperatures to produce the most natural effect. We tried very hard to use every possible structure to integrate lighting, so that each building element had its own identity but still contributed to the overall space.

The scheme involves many layers of lighting from a number of directions. This is deliberate and ensures the vertical and horizontal lighting is as even as possible — and yet the appearance is that it varies greatly. This is a good trick — in the darker areas there is more light than you would think, but in the brighter areas it is not as high as you would imagine. There is much written on horizontal illumination levels, but the key here is vertical illumination and how bright the space feels.

Despite the level of integration, there were large areas where we had to add light. The majority of the plaza illumination is delivered from three 20m bespoke stainless steel columns, each housing an array of individually focused LED spotlights. Strategically positioned to align with the historic station frontage, the LED arrays have been carefully designed to provide a low glare crisply functional appearance against the warmly glowing façade. Great effort went into placing and scaling them correctly, and then conducting an exhaustive and detailed design process to ensure they had the right feeling of permanence, solidity and elegance.

Glare was a concern for our clients where the columns were concerned. Views of the newly revealed façade were sacrosanct — and local residents, businesses and hotels also had to be considered. We designed the columns to have dual sources — one to provide focused, controlled downward illumination and one to provide a backlighting element to reduce contrast and also even cut the appearance. All lighting elements were specially made for the project and we viewed a number of mock-ups from iGuzzini before we were happy. Each spotlight on each column has been specifically aimed so that we created a very soft field of illumination across the square - without the glare often associated with these types of exterior lighting installations.

Smaller columns are positioned to guide commuters to the ticket concourse, and a variety of low-profile lighting elements have been designed into the various structures and forms — such as the benches and trees — to provide supplementary illumination and localised accent.

We had a number of clients on this project - Network Rail, London Underground, Camden City Council, Islington City Council. Transport for London and English Heritage — each of which had a different set of lighting standards. All of these vary in terms of luminance, illuminance, permissible colour appearance and colour rendering, adding to the complexity.

In addition, we proposed from the outset to design an all-LED scheme — we knew from the beginning this was the right route for the client in terms of energy, cost and maintenance cycles — which meant that most of these required proof that LEDs would provide the quality, quantity and longevity of lighting. We made sure that all products were robust, could be maintained easily and came complete with five to seven-year warranties.

As well as collaborating with the architect from an early stage — essential for the seamlessness of the scheme – we worked very closely with manufacturers to select luminaire types that could provide the right lumen outputs and be a small enough to successfully integrate into the architecture – elements such as the granite slots in the ventilation shafts are particularly small and we had a set opening (due to airflow and aesthetics) to work with. This lighting was needed to contribute to the ambient lighting levels while providing visual interest across the square.

The project led a number of manufacturers to create new LED luminaires and we pushed them to speed up their LED development. Aside from iGuzzini creating bespoke LED modules for the lighting columns, Selux introduced the LED M125 for the London Underground entrances and Kemps Architectural Lighting produced newly developed linear LED fittings.

The attention to detail is impressive across the square, the result of the close cooperation with the architect throughout the design phases and across the phased construction programme. The project has transformed Kings Cross Square from a neglected site into an exemplary public urban space – already well used by day and night.