Cycling inspired the concept for the Velodrome, the bike is an ingenious ergonomic and aerodynamic object, honed to unrivalled efficiency. We wanted the same application of design creativity and engineering rigor that goes into the design and manufacture of the bike to manifest itself in the building. Not as a mimicry of the bicycle but as a three-dimensional response to the functional requirements of the stadium. By applying the same thought processes and form finding approach, the aesthetics and shape of the stadium have emerged from the process.
As a publicly funded project in the public eye, the competition-winning scheme has been subject to numerous rounds of Value Engineering. These were embraced in a positive manner by the design team leading to further increase in the efficiency of the design and a reinforcement of the original concept. Not only has this enabled the design to remain on target in terms of cost but it has also ensured that the amount of material, embodied and operational energy has been kept to a minimum. As a result of the use of the structurally-efficient cable net roof structure it has been calculated that approximately 1000 tonnes of steel have been saved compared to a more standard form of roof.
The design strategy focused on minimizing demand for energy and water and integrating this into the fabric of the building to reduce reliance on systems and infrastructure. The daylighting strategy applied to the main cycling arena exemplifies this approach. Rather than investing in PVs on the roof of the Velodrome or other ‘bolt-on’ technologies, designing for maximum daylight proved to be a much more economical solution which yielded far greater benefits in terms of reducing carbon emissions. A great deal of effort was put into developing and optimizing rooflights in the main arena to provide sufficient daylight for training purposes for most of the year. Special diffusing glass was used to prevent patches of sunlight appearing on the track and to give a high level of diffuse light inside the building. Energy efficient artificial lighting linked to an intelligent control system can be used to provide elevated lighting levels for major events. This achieves the best balance between energy savings due to daylight use without incurring excessive glazing areas, which would compromise the thermal strategy of the building.
The main arena is highly insulated and fully naturally ventilated in mid-season and summer, significantly reducing energy demand. Extensive computational simulation was used to refine the area requirements for air inlets and outlets to achieve the required level of ventilation. These are seamlessly integrated into the building facades and in combination with exposed thermal mass in strategic locations allow passive cooling of the building in the warm season.
Rainwater is harvested from the Velodrome roof and stored in the undercroft at the west end of the building behind the berm. Recycled rainwater is used to supply the WC/Urinal flushing and any wash down points, along with irrigation of the Velopark when completed post–Games. Using the park-wide non-potable water only as top-up for the rainwater system in periods of low rainfall or high water demand and the use of water saving fittings throughout the building the Velodrome is predicted to achieve an annual reduction of 75% in potable water demand.
Due to their high sustainability aspirations the Olympic Delivery Authority has set a number of sustainability targets. Through carefully consideration and integration of the architecture, structure and building services the design has met or exceeded these requirements.
London 2012 Velodrome Project Facts
Gross Floor Area - 21,700 m²
Treated Floor area - 16,740 m²
Total Steel Weight - 1029 Tonnes
Environmental Rating - BREEAM Excellent
Total Project Cost - £95 Million
Architects - Hopkins Architects
Structural Engineer - Expedition Engineering
M&E Consultant - BDSP
Track Designer - Ron Webb
Main Contractor - ISG
Quantity Surveyor – CLM
Client – Olympic Delivery Authority
Construction Start - 23 February 2009
Contract Duration - 98 Weeks
Annual energy/CO2 consumption for space and water heating (excluding any contributions from onsite renewables which should be noted below) - 58 kWhrs
x 0.19 kgCO2/kWhr - 11 kgCO2/m2
Annual energy/CO2 consumption for electrical usage (excluding any contributions from onsite renewables which should be noted below) - 218 kWhrs
x 0.43 kgCO2/kWhr - 94 kgCO2/m2
CO2 emissions/m² treated floor area - 105 kgCO2/ m²
Notes on the Above Figures
Energy prediction calculations were undertaken at Design Stage E using EDSL TAS software. These were based on a Legacy/Post-Games operation with the building usage based on National Calculation Method with alterations to incorporate specific usage patterns identified in the Legacy Business Plan. Unregulated energy uses such as small power, external light, lifts and catering were accounted for in the energy prediction, including the extensive AV/IT installations (server rooms). The energy prediction calculations were undertaken by BDSP Partnership and were subject to external peer review by the Olympic Delivery Authority Sustainability team.
Olympic Park specific targets and methodology were set by the Olympic Delivery Authority for energy prediction and water consumption estimation. These allowed the evaluation of energy/carbon savings achieved in the design as well as potable water demand reduction in relation to ‘typical’ sports venues. The Velodrome surpasses these targets achieving estimated 75% potable water demand reduction (target of 40%) and 30% carbon emission reduction (compared to the 15% reduction target set by the ODA in relation to Part L requirements). BREEAM Exce llent has been achieved by the Velodrome at the interim design stage using a bespoke BREEAM assessment created for the Olympic and Paralympic venues.
The Velodrome benefits from the Olympic Park district energy network. In this way, the Velodrome not only benefits from but also contributes to the wider energy strategy of the Olympic Park, using the larger scale as a way of reducing the overall environmental impact of the Park as a whole. The electricity and heating provided to the building thus come partially from renewable or low carbon sources. Heating is provided by biomass boilers as well as CHP (combined heat and power) plant, reducing carbon emissions associated with heating by approximately 30%. Electricity also comes from the CHP plant, with a reduced emissions rate of 0.264kgCO2/kWhr (37% reduction). Overall, the CO2 emissions of the building taking into account this contribution is 67kgCO2/m2.