Velodrome for the London 2012 Olympic and Paralympic Games, by Hopkins Architects
Hopkins’ Velodrome is a six-week show-stopper that’s built to last, says Hattie Hartman. Photography by Richard Davies
A good brief doesn’t always mean a good building, but it certainly helps. The Velodrome had two enormous advantages over the other major London 2012 venues: a clear brief and an end user.
Nothing demountable like Populous’ stadium, no temporary wings like Zaha Hadid’s Aquatics Centre. A 250-metre track and 6,000 spectators - both during the Olympic and Paralympic Games and in legacy - were fixed from the outset.
In marked contrast to the current debacle over the conversion of the Olympic Stadium into a permanent football venue, the Velodrome benefitted from the early input of a cycling club which was previously located on the site.
The volume is very taut with nothing superfluous
Its users were consulted early on to clarify how the Velodrome - primarily a venue for elite cyclists - could also become a hub for amateur cycling enthusiasts.
The legacy business plan anticipates capacity audiences around six times a year, with typical daily use by school groups and cycling clubs averaging fifty to a hundred people during the week and more at weekends.
The Velodrome was not without its own design challenges, starting with its highly variable occupancy pattern.
Moreover, Olympic cyclists require warm temperatures - 26-28°C - which lowers air density, enabling them to shave milliseconds off their times. But spectators must be kept cool, even on warm days with capacity crowds during the Games.
Lastly, the Velodrome sits on one of the most contaminated sites in the Olympic Park, the former West Ham tip. Costly excavation had to be kept to a minimum.
Selected through competition from a shortlist which included David Chipperfield, FOA, Wilkinson Eyre and FaulknerBrowns with Heatherwick Studio, the team led by Hopkins Architects senior partner Mike Taylor proposed a double-curvature structure wrapped around the track, with a glazed concourse allowing views onto the track and over the park.
Another key initial concept was to split the seating into upper and lower tiers so the Velodrome would not feel so vast when partially occupied.
Given its modest occupancy in legacy and prompted by the Olympic Delivery Authority’s (ODA) sustainability agenda, the design team sought to create as efficient and compact a venue as possible, envisaging the building as a track with a ‘shrink-wrapped’ envelope.
‘We wanted it to feel like a bicycle in terms of its engineering, very taut with nothing superfluous. The volume is as tight as we dare go. Everything is sort of on the edge,’ says Taylor.
The result is elegant and memorable without being monumental.
Inside, the sloped track of Siberian pine combines with the birch-ply underside of the roof cassettes, the blue infield and the neutral grey seating to create a sense of airiness and light.
Midway through design, the discovery of contaminated soil meant that the building had to be raised 1.6 metres out of the ground to minimise excavation. The building sits high, sailing over the site.
Conscious of what it’s like to be a pedestrian approaching a 22-metre high building, the architects have worked hard to mitigate the scale of the building for passers-by, burying the concrete seating bowl. Landscaping has yet to mature, so it’s difficult to judge the final experience of circumnavigating the completed building.
Refining the design was an iterative process between the architects and engineers Expedition for structures and BDSP for services.
BDSP’s Klaus Bode says that the delivery of this environmentally performative building was only possible due to truly integrated design.
‘Each member of the team was willing to look beyond their own remit, and that included the designers, client and contractor,’ says Bode.
The early engagement of contractor ISG at Stage C was critical in determining the building’s most innovative feature: its double cable-net roof.
Although early costing studies had indicated that a conventional steel roof would be cheaper, one of ISG’s first moves was to commission a study which examined the cost, programme and environmental aspects of different roof options.
The cable net option eliminated three months from the programme, saving £2 million and significantly reducing the amount of steel in the roof. At 30kg/m2, the London cable net roof weighs less than half of the Beijing velodrome’s roof structure.
Rooflights provide daylight and reduce electric lighting loads, immensely logical given the Velodrome’s predicted low occupancy.
Discussions with the International Olympic Committee are ongoing on whether to change its standard approach of blacking out all venues during the Games before installing high-definition lighting for television.
No matter how this is resolved, the Games are just a six-week blip in the life of the Velodrome, so what is key is the legacy design.
The ODA’s sustainability targets, particularly for 20 per cent recycled content in materials, drove both architects and contractor to carefully interrogate specification choices.
Hopkins Architects partner Chris Bannister notes that they were also useful in holding on to aspects of the design during value engineering. ISG’s Simon Attwood, who monitored sustainability throughout construction, observes that early contractor involvement meant an eight-month lead in time, luxurious by most project standards.
With ISG’s input, much of the shuttering for the concrete was re-dimensioned to eliminate 100mm cut-offs, reducing plywood waste on the job from the industry standard of 20 to 3 per cent.
When the fireworks of August 2012 fade, London will be left with a series of buildings in a park in Stratford.
Will Londoners make the trek to the Queen Elizabeth Olympic Park for a day out? Will it become one of London’s visitor must-sees?
Will it be a green lung for a regenerated Stratford and a community recreational outlet, attracting a lively mix of residents and visitors? In Munich, almost 40 years later, Olympiapark - also located off-axis from the city centre - is a popular, vibrant place.
The London Velodrome sets a high standard, full of promise, and is likely to become a destination not only for cyclists but also an orienting landmark for park users and motorists on the adjacent A12.
But its success will depend on careful programming of the park’s public realm to draw a large and diverse audience.
London 2012 - Sustainable Design: Delivering an Olympic Legacy by Hattie Harman will be published in late 2011
Because of the Velodrome’s low occupancy in legacy, engineers BDSP examined the viability of an unheated venue, but thermal modelling demonstrated that it would not be possible to achieve the high temperatures required by cyclists on the track without heating.
Therefore, the design team made the venue as compact as possible to reduce the volume of air which needs conditioning; the cubic volume of the final building is 15 per cent leaner than the competition scheme.
The envelope is heavily insulated and has what Hopkins’ Mike Taylor refers to as ‘a clever breathing strategy’. That means that both heating and ventilating can be easily adapted to different occupancy patterns; the building has no cooling, with the exception of its few offices and the server room.
Underfloor heating supplies the track where temperatures are critical. In summer, the building is entirely naturally ventilated without fan assistance.
Air passes into a plenum under the seating tiers through louvres in the timber cladding and into the occupied arena through perforations in the risers under the seats.
The stack effect evacuates exhaust air through the cladding louvres at the building’s two high ends. In winter, rapid-response boost heating can be supplied by modular air-handling units located in the same plenum under the seating.
The air-handling units can be switched to feed either the same perforated risers under the seats or jet nozzles in the vertical face of the floor structure.
Start on site 23 February 2009
Contract duration 98 weeks
Gross internal floor area 21,700m2
Total cost £90m
Form of contract NEC3
Client Olympic Delivery Authority
Architects Hopkins Architects
Structural engineer Expedition Engineering
M&E consultant BDSP
Legacy landscape consultant Grant Associates
Facade engineering Arup Facades
Acoustic consultant Paul Gillieron Associates
BREEAM assessor Southfacing
Track designer Ron Webb
Main contractor ISG
Quantity Surveyor CLM
Fire engineering Arup Fire
Crowd engineering Arup Crowd
Roofing Kalzip and Sarnafil
Curtain walling Schuco
Light fittings Phillips
Predicted annual C02 emissions 67kg/m2
CO2 emissions reduction beyond Part L 2006 31%
Recycled content 28% (target 20%)
Bowl: 0.15 W/m2K; Glazing: 1.3 W/m2K; Roof: 0.15 W/m2K; Floor slab: 0.24 W/m2K