Blinds & Shutters hears about the work carried out by Levolux and Lutron at Unilever House which has ensured the additional natural light created by an updated building causes no problems

Seventy years on, this Grade II listed building was in need of major refurbishment to meet Unilever's present-day operational needs.

After almost four years of work, the redevelopment is now complete and the dark interior of Unilever House has been replaced with an airy, state-of-the-art working environment. With this alteration, Unilever HQ has been presented with a new challenge – how to manage so much additional natural light. Working alongside companies such as Lutron and Levolux, the latest in natural light control technology has been installed to manage the ever changing balance between the artificially and naturally lit interior.

With a corporate mission statement to “add vitality to life” Unilever achieved this in a very physical sense when it initiated the refurbishment of Unilever House back in 2004. Following an extensive consultation process with Unilever, the City of London and English Heritage, proposals were developed by architect’s, Kohn Pedersen Fox Associates (International) PA, that achieved a balance between retaining the important historic fabric of the building – including the dramatic front façade – whilst providing a transformed workplace and spatial experience for the many visitors to the building.

Increased interior light levels were a requirement on the initial brief and the end result speaks for itself. The horizontal dichroic glass fins on the new west façade emphasise the play of light within the atrium with an ever changing spectrum of colour throughout the day, whilst the internal floor plan focuses on maximising natural light as much as possible. With the increased light levels came the challenge for Kohn Pederson Fox Associates to find a suitable method of managing the introduction of this immense amount of natural light to the interior spaces.

Solar heat gain and glare throughout the South Easterly side of the building were major issues for the architects. Unilever House sits 45 degrees onto the Thames, giving it some of the best views of the river, however its position also means that the 8th floor dining area, director’s dining room and meeting spaces, as well as all cellular offices from floors three to seven are vulnerable to considerable solar heat gain and glare as light levels increase throughout the summer months.

Working alongside Levolux over 200 electronically controlled fabric blinds that manage solar heat gain and glare were installed throughout the South Eastern and Northern sides of the building alongside blackout blinds for particular meeting rooms. In addition to solar heat gain and glare, there were concerns about the aesthetic appearance of the blinds when viewing the building from the exterior, thus marring the overall impact of the highly symmetrical Art Deco facade. Kevin Bloxam, director, Levolux commented: “Apart from solar heat gain and glare reduction, one of the principal remits on the job was to manage the internal natural and artificial light levels, whilst avoiding a 'gap tooth smile' effect from the blinds that were not lined up at the end of the day. With this in mind, I recommended that Levolux fabric roller blinds be installed with Lutron’s Sivoia QED motor drives. Not only do the drives have near-silent mechanisms, but they can be interfaced so precisely that the blinds will all lower and rise at exactly the same level across any number of windows day in, day out.”

Lutron’s Sivoia QED technology is a sophisticated and versatile electronic drive for controlling roller blinds and curtains and allows for complete control of natural light in commercial applications. Sivoia QED was designed with flexibility in mind and as such, does not require group controllers, relays or line-voltage wiring between Electronic Drive Units.

Programming is easy and can be reconfigured at the point of control without rewiring or access to the Electronic Drive Unit. As well as Levolux linking the Sivoia QED eletronic drives to Lutron keypads for individual control as required, the entire network of blinds at Unilever House was also linked to Levolux photosensors. Kevin continued: “The linking of the blinds to photosensors has enabled all of the blinds to be progammed to lower and rise automatically throughout the floors as light levels alter throughout the day and evening. This also has the added benefit of ensuring that at the close of play each day, the ‘gap tooth smile’ is avoided.

”The end result at Unilever House speaks for itself. The 350,000ft2 of the structure has been stylishly redeveloped providing Unilever with high-quality, flexible spaces ideal for the company’s modern office and operational requirements. In the words of the ‘Morning Post’ who wrote about the opening of the building back in July 1932: "Unilever House will delight the eyes and minds of all who appreciate beauty in Architecture".

• Lutron