Project of the week: Sky's Osterley HQ
The new 'Sky Central' building on Sky's Osterley campus, built by Mace, has just opened after three years' work. Alan Robertson, operations director at Mace, talks to James Kenny about the challenges of taking on Europe's largest timber roof and adapting plans to meet Sky's high expectations.
Describe the project
The £210m building is the latest to open on Sky’s HQ campus in Osterley, west London. Named “Sky Central”, it is home to 3,500 workers from the whole 7,500 on the campus and provides all front and back office facilities.
The three-story 37,000 sq m building has a large triple-height central atrium above a 100m-long stretch on the ground floor which connects the main entrances – this has been dubbed “Sky Street”.
The working area has been split into 18 different areas or “neighbourhoods”, where people can exchange ideas, converse and such.
One of the building’s highlights is an elevated, glass-walled live Sky News broadcast studio that visitors and people can see as soon as they enter.
Also of note is the roof, which was designed to maximise natural light. It has a grid of skylights that allow daylight to penetrate through the building and light up workspaces, reducing facade glazing and reliance on artificial light.
For staff and visitors there’s also a Waitrose, which is the UK’s first ever completely cashless supermarket, six different places to eat and drink as well as a 200-seat 4K Sky cinema and a tech central area.
Sky Central was built under a JCT 2011 design & build contract, two-stage tender. The overall project value was £210m, the base build is about £190m and then a £20m fit-out.
Sky acquired the Osterley campus in 2011 with a masterplan to build a number of buildings across the 13-hectare media campus. Mace was contracted for the Central building and work began in 2013. It was finished in April 2016, the fitting out was going on concurrently, and they moved back in July.
Among those who worked on the building were: AL_A (building concept), PLP Architecture (interior and executive architect), Hassell (workplace design) and Arup (engineer).
What did the works entail?
Working with engineer Arup, it was decided that modularisation and offsite prefabrication should be used for much of the build, mainly to ensure that there was no major disruptions to the full Sky campus, but also to keep costs down, on track and firm up health & safety on site.
The primary structure is a reinforced concrete frame on a 9m x 10.5m and 9m x 9m grid, stabilised by six concrete cores. There are 6km of glulam beams on the project. The roof is 1.3m deep timber fins at 3m centres, spanning 18m and 21m, to support a lightweight timber cassette roof deck and skylights.
The cassettes, including skylights, were prefabricated offsite and raised into place in 10.5 x 3m sections, helping the high speed of construction.
You had worked with Sky before on other projects, how did this inform Sky Central?
We worked with them before to build the 3,000 sq m “Believe in Better” building, which is also on campus and is our educational facility for graduates, apprentices and staff training. We also worked on a health and fitness centre. So we knew the high standards and what they expected from us, it also gave us a taste for working in the area and the logistics of working in a busy HQ.
What was the big challenge on the Sky Central project?
Besides the roof, which is one of the largest timber roofs in Europe, I think it was just managing Sky’s expectations. They know what they want and we wanted to deliver it. The work was taking place in the midst of a fully operational media headquarters, so extensive planning with regard to logistics and noise was needed.
We also had to alter the plans to not only reduce costs but to improve overall elements of safety. The design of the more than 400 roof light cassettes changed from a metal composite to the better-value timber option.
We also altered the roof design from timber-clad steel beams to glued laminated (glulam) timber. By pre-assembling these offsite and in multiple locations we reduced the need to work at height and other hazardous jobs.
What were the key innovations?
I had not worked on a project with so much technology linked to it. Obviously working at a Media HQ means the construction is planned and centres around the ongoing use of the studio as well as installation of a huge number of screens everywhere. I hadn’t done such an amount of tech before on a project, screens, computers and everything wired and connected obviously, so working on that was interesting.
There’s probably been a few, like in most jobs. I guess one was when the fitting-out was coming together and the building was almost complete. The roof finish was obviously a very big one, it’s such a huge roof and really is impressive.
From my personal point of view it’s just seeing people here and the place working, seeing the studio in use and the news readers live, it’s really fantastic to see the buzz. The buzz at a live studio is just unique.
All images: Hufton + Crow
Concept Architect: AL_A
Interior and Executive Architect: PLP Architecture
Workplace Design: HASSELL