Designed to boost Heathrow’s capacity by 30 million passengers, the single-span terminal building is the largest in the UK. Speirs + Major was commissioned in July 2000 to solve the numerous challenges of lighting a range of external and internal spaces, including entry roads, car parks, bus and rail stations, terminal buildings and a new air traffic control tower.

The lighting solution was developed through two routes. First was a holistic approach, which involved masterplanning the lit image of the entire T5 campus. The second looked at evolving ways to ensure the proper delivery of the system for each individual area of the project.

The primary objectives were to maximise the use of daylight, assist with the routing of passengers, support wayfinding, provide general illumination for flexible spaces, and develop a distinct character for each key area. There were also secondary aims which included facilitating the strategy for general signage, supporting the objectives of the retail schemes, integrating with the requirements for commercial displays and providing the opportunity for change and spectacle.

All these aims had to carefully balanced with a wide range of design criteria, including the need to maintain a safe and secure environment, meet energy targets, consider buildability and make sure that the lighting system would be both robust and easy to maintain.

Despite its massive scale, the final scheme for Terminal 5 demonstrates how a simple, well-devised design strategy can be carefully communicated over a long period across a wide range of contractors and suppliers to achieve a consistent quality of both light and detail.