Sky opens up to timber

Media behemoth Sky’s marketing tag is ‘believe in better’, so expectations were high for the design of its flagship HQ building. Ray Philpott finds out if it lives up to the hype

Sky Central in Osterley, Middlesex, is an impressive building that successfully combines two distinct but equally effective design aesthetics.

From the outside it is a large, striking and elegant silver aluminium and glass envelope, a calm, sophisticated and slick reinterpretation of an industrial warehouse. Step inside PLP and AL_A’s building and you are struck by a large, open, busy space with a light-filled, with a three storey high atrium at its centre, giving off a real buzz.

The building’s expansive interior, large areas of timber roof structure, oak flooring and wooden staircases have a distinctly warmer feel than its glossy and cool envelope would indicate.

At ground level a busy circulation area, known as ‘Sky Street’, runs east to west for 100 metres. From there a whole range of facilities can be accessed, including six cafes and restaurants, a dry cleaner, postal services, shoe repairs, a cashless Little Waitrose supermarket, and a 200-seat cinema with a state of the art sound system. Informal and large meeting areas plus a major open event space have been created in column-free areas.

A series of ‘neighbourhoods’ – team-based work spaces for up to 200 people – surround the atrium, all but one on the first and second floors. These neighbourhoods offer wide vistas where workers can see ‘hub’ activity or look across at each other.

Glass-sided lift shafts and exposed ramps and staircases located on the outer edges of the broadly H-shaped atrium link all three floors together, and have been carefully designed and positioned to reinforce the feeling of space and light.

A series of stacked, floating mezzanines, set slightly below normal floor level, serve as ‘breakout’ areas and connection points for the lifts and stairs.

Presiding over all of this is the Sky News Studio, a large transparent glass box on the second floor above Sky Street, where presenters can be watched broadcasting live news as people go about their work. Clearly, this is not a typical office.

Concept

Launched in 2016, Sky Central is the largest building to be added to Sky Campus, the UK-based broadcasting giant’s headquarters complex in the West London suburb of Osterley.

While architect AL_A was responsible for planning and the overall external concept, PLP Architecture was appointed by Sky as the interior design and executing architect in 2013 with a brief to “reimagine” the interior of the building.

“Sky wanted something game-changing and intuitive,” explains PLP director Cindy Lau. “Our design needed to support a wide range of agile working styles and the evolving structures of teams, stimulate collaboration and encourage chance, unexpected interactions between people. Sky also wanted the building to support employees’ wellbeing.”

PLP responded with an internal architectural design promoting flexible and collaborative workspaces by creating 11 distinct neighbourhoods around a central hub linked by the mezzanines. At the same time the concept sought to generate a bright, open space promoting visibility and movement, a place where people could easily interact.

To achieve this, the architects felt some changes were required to aspects of the design concept, primarily the roof and circulation areas.

Lau comments: “The original design was intended to be read as a shed with a floor to ceiling space that created a sense of light and openness. We decided to take that a step further.”

Industrial chic

Building on their experience of office projects in the City and working closely with structural engineers Arup, the architects redesigned the roof to create greater concentrations and quantities of skylights bringing in more light, and amendments were made to the recessed glazing in the external walls.

While timber was always part of the original roof concept, PLP accentuated its use, employing 1.3 metre deep spruce glulam-beams up to 21 metres long and spaced 3 metres apart to support a prefabricated timber cassette roof deck.

This structural approach opens out – and reduces the density of – one of the largest timber roofs in Europe, enabling increased use of glazing.

The dimensions of the floor plate were also revisited and the atrium reconfigured into a single large central area that spatially feels more open without losing floor space.

Structurally, the building is built around a concrete frame on a 9 metres by 10.5 metres and 9 metre by 9 metre grid, stabilised by six evenly placed concrete cores. The design shifted circulation services out of the cores and into the atrium, enabling the architects to regain some internal floor area.

“Moving the stairs and glazed lift shafts into the atrium created a vertical circulation area connected by mezzanines and made them highly visible architectural features to be celebrated,” Lau points out. “When you arrive there’s a sense of movement and animation created by a combination of people’s activities and the mechanics and inner workings of the lifts and services on show.”

Lau continues: “The mezzanines and circulation areas are designed in an architectural language of industrial chic Sky wanted, separating them from the concrete superstructure.”

“Everything within the atrium is of lightweight construction, much of it prefabricated off-site. We made extensive use of timber framing, architectural steel and oak flooring. For example, we used those materials on the stairs and on the mezzanines, while a structural timber frame runs across the whole width with oak flooring on top in place of more typical concrete decking.”

Wiring, ducting and other services are deliberately on view as part of what Lau describes as the “honest design ethos”. Crucially however, the architects worked closely with the engineers to carefully plan and implement the building’s lighting and other essential systems so service installations on show are visually balanced, not random and potentially unsightly by-products.

Flexibility

Externally, the long exterior of building is broken up by a series of 1 metre-deep reveals holding the glazed elements incorporated to add interest to the overall facade reading and providing passive shading to the windows. Sky wanted its exterior to share a similar architectural palette applied to other recently completed buildings on its campus; the Believe in Better Building, The Hub and Sky Studios all feature silver-coloured finishes.

However, the interior design of Sky Central isn’t required to follow the other facilities. Nevertheless, bearing the future in mind, PLP chose a limited colour palette, primarily utilising neutral white and grey along with timber tones.

“We believe architecture should stand the test of time and this building offers clients the flexibility to change things later on,” points out project lead and PLP Director Wayne McKiernan.

PLP’s 200-person ‘neighbourhood’ concept also offers the flexibility needed for the kind of agile working Sky favours. At full capacity there’s only enough desk space for 70 per cent of the 3,500 working there, and no-one has a personal desk.

McKiernan says: “Each neighbourhood is self-sufficient but sharing two ‘home zones’ with its adjacent neighbours. The Home Zone is an on-floor kitchen for preparing drinks and food, bringing a human touch, and acting as familiar landmarks within the very large floor plates.”

They share a range of common elements, including: breakout areas; formal meeting rooms and open meeting areas; plus quiet, standard and larger ‘shared’ desking types.

In helping create the work environment PLP liaised initially with Sky’s own work space team, and later with experts from specialist in the sector Hassell to configure the work spaces, particularly regarding how the common elements are positioned and interact with the internal architecture and services.

Again, the grey, white and timber palette is applied across the neighbourhoods, along with other common features such as timber flooring, black steel frames to demarcate open areas and wall tiles for the breakout areas.

“Although the appearance of common elements vary slightly between neighbourhoods, Sky wanted each neighbourhood to be broadly similar, not designed around a specific team.

“That way if an individual moves, or a team changes neighbourhood, familiarity is maintained and transitional confusion minimised,” explains McKiernan.

Sustainability Being keen on sustainability, Sky drove significant use of timber and extensive internal planting involving some 27,000 plants. The structure’s been awarded a BREEAM Excellent rating but the company has endeavoured to exceed that standard where possible.

It utilises a highly efficient thermal model combining fabric design and an internal system selection which aims to reduce overall carbon emission by up to 40 per cent better than current legislation. Some 1400 highly efficient PV panels have been installed across the roof, generating power, while triple glazed north-facing skylights with low-e side glazing, combined with passive internal shading form the glulam beams, help to reduce solar gain.

Rewarding

Reflecting on the project, Wayne McKiernan comments:

“We had a very tight two-year window to design and complete the project after our appointment in 2013.

“So we were carrying out the design with construction already in progress, which was pretty challenging but thanks to a combination of our experience and great, established working relationships with the engineers and Sky’s team, we achieved the project’s ambitions.

“Sky were extremely encouraging and allowed us to break away from the design of a typical office building – we had the freedom to create a truly ground-breaking work environment.

“Ultimately we’ve created a building with the kind of inner space you just wouldn’t expect from outside. When you walk in and see live broadcasting taking place right in front of you, surprise and excitement grabs you straight away. That’s very rewarding for a visitor and leaves a lasting memory.”