The Velodrome is the most energy efficient building on the Park, with a 31 percent improvement over Part L of the Building Regulations. There were some key challenges in achieving this, but a collaborative, interdisciplinary approach to working resulted in a naturally lit and ventilated design that has excelled in carbon efficiency.
KEY CHALLENGES FOR THE DESIGN
- Cyclists prefer higher temperatures (78–82°F) as lower air density means they can gain a few milliseconds and break records.
- Spectators want to be cooler.
- Games/events lighting requirements are energy consuming and heat emitting.
- There are restrictions in opening windows at ground floor level due to security/safety concerns.
The Project team adopted the philosophy of primarily minimizing demand for energy as far as possible through passive measures. They carried out energy modelling early on and analysed the energy systems to achieve the best efficiency.This high level of energy efficiency was achieved by putting sustainability at the core of the design from the onset and getting a combination of energy efficiency measures to work together as a complete, integrated solution:
Natural Ventilation - The Main (passive) cooling strategy for most of the building, with active cooling restricted to rooms with high concentrations of people or equipment (for example, conference rooms and server rooms).
Compactness - Achieved by designing a double curvature roof, minizing the overall heated volume of air in the main cycling arena. The high ends of the roof allow heat to rise out and also help with extra seating.
Glazed Areas - (Windows and Roof Lights) were optimized, allowing adequate daylight into the field of play and also into administration spaces (such as offices), reducing dependency on artificial lighting energy.
Thermal Mass - In the form of exposed concrete, this permeates most of the building's rooms, which, coupled with night ventilation, moderates the internal environmental conditions and reduces energy demand for heating and cooling. Night time purging.
Improved Insulation - In the external envelope, and mainly in the roof helps minimize heat losses in winter, thus reducing the heating demand.
Air Tightness - Assured through careful detailing and cooperation with the main contractor to ensure high standards of construction.
Ventilations Systems - Including low fan power due to short duct runs and heat recorvery (Air Handling Units (AHUs)) are located under the upper tier seats, within the ventilation plenum and close to air intakes, minimizing duct runs.
Air Recirculation - Will be used whenever possible (when not fully occupied) to reduce heating energy consumption.
Heating - Provided by a combination of underfloor and air heating, taking advantage of low temperature systems for base load, but allowing rapid response for events and other special occasions.
A Building Management System (BMS) - Coupled with sensors is designed to control the building mechanical, electrical and plumbing (MEP) systems, assuring efficiency.
Variable Speed Inverters - Control fans and pumps and reduce electrical demand.
Future proofed design enables windows to open (at ground floor level), when security might not be such a prominent issue. Night ventilation controls are included in the BMS, but can be overridden by the operator in case of security concerns.
Ventilation Vents - Can be closed in winter to retain heat. Vents also work during the night for a night purging (without incurring a security problem). The size and detailing of the holes was refined to support passive ventilation and also stop light spilling out.
Low Energy Light Fittings - Specified throughout the building, coupled with appropriate lighting controls, daylight linked wherever possible.
3D Modeling of the services - used to prevent clashes and allow a very compact design (which was therefore also cheaper).
The Velodrome demonstrates best practice in low carbon design, particularly in an elite sporting complex. Although there are many individual elements that contribute to this, it is the successful integration of these solutions that creates the biggest win. Undoubtedly the most important contributor was the early decision to instil a culture of interdisciplinary working within the Design team.
This type of working not only requires strong leadership, openness and flexibility, but also needs to have systems and tools in place, such as 3D modeling which allow the team to optimize the design and check their assumptions at each state of the design process.
The interdisciplinary approach and passive design principals have not only resulted in a low carbon footprint and reduced energy bills for the Legacy owner, but also informed an elegant design which has recently been shortlisted for the prestigious RIBA Stirling Prize.