Since the term “Silicon Roundabout” was coined in 2008 to describe the changing face of Old Street, the area has become a vibrant community of start-ups and established digital corporations.
As well as the technical revolution going on, the area at the edge of east London has undergone changes in construction, particularly around the roundabout itself. The egg-shaped apartments, in the south-east corner, have been a talking point over the past few years, dividing Londoners with their unusual structures.
Client Derwent London
Main Contractor Multiplex
Architect Allford Hall Monaghan Morris
M&E Engineer Arup
Structural Engineer AKT II
Project Manager Jackson Coles
CDM Coordinator Jackson Coles
Quantity Surveyor Aecom
Specialist Facade Engineer Arup Facades
Fire Consultant Arup Fire
ICT Arup IT & Communications Systems Consulting
However, it is next to this, in the south-west corner that another striking building is nearing completion. With its cladding aptly looking like a circuit board, the White Collar Factory is being championed as a new type of office for a new way of working. The £76m project is aiming to be greener and much more flexible than traditional speculative office developments, with bare concrete walls and exposed services as well as cutting-edge technology and IT interfaces.
The overall concept of the 16-storey building centres on tried and tested environmental principles: large open floors and tall ceilings for flexibility and good daylight; an exposed concrete structure for thermal mass; and natural ventilation to reduce energy consumption.
Central to achieving a better indoor air quality is the skin of the building itself. It is wrapped in a facade where shading, glazing, openings, and insulation are tailored to respond to each elevation’s orientation to the sun, which means each facade is designed differently.
Jonathan Wilson, facade engineer at Arup, explains that from the start developer Derwent London and architect AHMM were keen to move away from the traditional London offices that feature traditional glazing. They wanted to develop a facade that responded to the low-energy cooling system, maximised daylight, provided natural ventilation and responded to the high acoustic requirement demanded by the site, as well as responding to the “White Collar Factory” industrial aesthetic.
How the panels are designed to suit the orientation
Wilson says: “During the early design phase of the project AHMM, Arup and other consultants were all involved in client presentations to Derwent on the facades of the White Collar Factory, where Derwent was a fundamental partner in the development of a truly performance-led multi-functional facade design. This was all done prior to any tenders and before any work was done to ensure the facade met the performance requirements of the building.”
The basic module component is a unitised curtain walling system, which is broken down into three key elements: opaque; fully glazed; and glazed 2m high inward opening windows that are partially shaded by large perforated panels.
The external perforated panels are a key feature of the facade. The 4mm-thick natural anodised panels have vertical corrugations pressed into them as well as the large punched holes. According to Wilson these were inspired by Jean Prouvé’s Maison Tropicale, a 1950s prefabricated housing system. “It embodies the factory aesthetic that the building is about,” says Wilson.
During the early design phase the architect, facade engineer and building services engineer worked closely to define the balance between glazed and opaque based on solar and thermal performance. Parameters in terms of glazing percentage depending on orientation were supplied to the architect allowing them to develop their elevations.
The shading factor of the perforated panels helped to maximise the amount of glazing. A double-glazed unit with a highly selective solar control coating was selected. The glass was chosen based not only on its shading performance but also to maximise the amount of visible light the glass allowed into the building. Once the parameters had been set for the performance of the glass, sampling exercises were undertaken to inspect the visual quality and colour of the glass.
The unitised curtain walling
Following the appointment of the main contractor, Multiplex, the design team was novated and Yuanda Europe, the European division of Chinese cladding contractor Yuanda, was awarded an £11m contract to develop the design and fabricate the building envelope.
Wilson says: “So there was one main facade panel used predominantly on all the facades from level one upwards
and that’s the unitised system manufactured in China. The Prouvé aluminium panels and glass were made in Europe and then shipped to China where the facade elements were assembled in strict factory conditions.”
Wilson says all parties – Multiplex, Derwent, AHMM and Arup – were involved in all stages of the design and sourcing and this was key to ensuring a smooth supply chain and that the products were of the right standard.
“When Derwent went to China to see the facility with Multiplex and AHMM, at that time we had built several mock ups of each of the main facade types so they could sign off. We went out to China three times ourselves as Arup, but worked closely with our facade engineers in our Beijing office who made regular trips to Yuanda’s factory and also to North Glass, the glass supplier.”
“That was fundamental to the success of the project, Yuanda knew we were going to work collaboratively with them to ensure we delivered the best.”
Further up on the top two floors of the building there are also a number of porthole windows which can again be opened by the occupants depending on the needs of the workers.
One of the biggest challenges on the project according to Wilson was the fact that the building is located on one of the most active roundabouts in London, almost constantly busy and noisy.
“We worked with Arup Acoustics and their technicians at design phase on testing the outside to inside acoustics. As you go up the building the glass spec slightly changes in terms of the build-up glazing that responds to the external noise environment.
“One of the innovations in the facade design was the incorporation of a perforated acoustic panel on the inside of the opaque elements. The ‘factory’ aesthetic lead to the use of exposed internal concrete soffits and structure with minimal options for inclusion of sound absorption. The facade acoustic panel was fully integrated into the united element and helped to respond to the internal noise conditions.”
Arup also conducted two full scale weather performance tests on the facade with an aeroplane engine simulating various harsh weather in order to ensure it could withstand all conditions.
“The facade had to perform well in every sense, thermal, solar, acoustics and aesthetics.”
The panels were shipped to Europe in a container and according to Wilson due to it being unitised work on construction and the cladding was much easier and could “slot in easily”. Work began October 2015 and cladding was completed last August.
Tried and tested – from tech to temperature
Nothing left to chance in digital and sustainable exemplar
One of the key innovations and principles underlying the design of the White Collar Factory building is to optimise the climate control benefits of its passive design to reduce the amount of mechanical air conditioning needed.
To do this it uses concrete core cooling, which works by circulating chilled water though the pipes embedded in the floor slabs. The cooled slabs provide radiant cooling and thermal mass to absorb any heat generated in the offices from computers, lighting and people.
Unlike conventional air conditioning it is a passive cooling system which is quieter to run with less air movement within the space.
Besides the concrete cooling system, careful thought has gone into the rest of the design to integrate new tech and IT. This can be seen in the openable windows throughout the building. There will be a traffic light system on each floor to guide occupants on when to have the windows open and when to close them depending on the outside temperature: green for open, red for closed.
Workers and building managers will also be able to “see” in real-time how the space they’re working in is operating via an app linked to the building management system – and provide feedback to improve comfort and energy performance.
The building is the first in the UK to achieve a Wired Certified Platinum for Development & Redevelopment rating.
The Wired Certification scheme was launched by former mayor of London Boris Johnson in November 2015. It acts as a trusted mark for buildings independently certified to provide leading-edge digital infrastructure. It’s meant to give greater transparency to tenants signing leases and provides landlords with insights to improve their building’s connectivity standards. White Collar Factory will provide 237,000 sq ft over the 16 floors of office space with super high-speed connectivity.
Another example of forward thinking on the project was that before actual construction started, Derwent built a full-scale working prototype, essentially a 325 sq m slice of the White Collar Factory floor. The prototype building not only served as a marketing suite but also as a testing facility for its tech and how the building would work with its environment.
Throughout the summer and autumn of 2013 bespoke software, installed on an iPad, was used to test how much energy was being consumed within the prototype and to monitor comfort levels. The prototype was populated with workers and monitored to see if the office they inhabited was a suitable environment.
By populating the prototype and then monitoring conditions throughout a hot summer and variable autumn season the designers were able to verify the performance of the building services design before work started.
French dressing inspires White Collar design
Architect Jean Prouvé’s industrial look informs Derwent’s building
The £76m White Collar Factory has already inspired its own buzzword with developers and designers exclaiming they want the new “White Collar look”.
Work began on the project in 2014 and it is Derwent London’s vision of a new type of office aiming to revolutionise the workplace.
The concept for the design of the new office buildings is one that combines well-built industrial spaces with best practice office design, based around the principles of reducing lighting, heating and cooling while allowing maximum flexibility and adaptability.
It is inspired by mid-20th century French architect Jean Prouvé, who introduced manufacturing technology into architectural design, bringing a bare, stripped-back, industrial feel, but with 21st century technology.
The office building is the centrepiece of contractor Multiplex’s commercial office-development Old Street Yard. The development comprises six new builds, including the refurbishment of two buildings. Behind the tower, the redundant service yard will be surrounded by five low-rise buildings providing offices, restaurants and apartments.
The 16-storey 237,000 sq ft office building also has a roof terrace with an integrated running track.
The stability of the building is provided by two reinforced concrete cores. The floor slabs are supported on a 9m x 9m grid with varying spans in parts based on a multiple of the 1.5m internal planning grid. All floors are constructed from in-situ reinforced concrete which is left exposed on the underside.
Internally, the clear floor-to-ceiling height is 3.5m, which includes a 200mm-high raised access floor for electrical services and ICT, including a fibre optic “spine”.
Much of the concrete structure is exposed. A “board mark” finish – achieved from carefully selected timber shuttering – is being used for feature walls in reception, the ground floor external walls and the walls of the lift lobbies.
The building has already been 60% let to companies such as Adobe, AKT II, BGL, Capital One and The Office Group. Seen as the crowning glory, the building’s top two storeys comprise a double-height penthouse with an open mezzanine level.
