The Heathrow Terminal 5 project was one of Europe's largest and most complex infrastructure projects, with a peak monthly spend of $80 million and up to 8,000 workers on site. The construction of T5 consisted of 18 main projects divided into 140 subprojects across a 260 hectare site. It was completed in two phases from 2002-2008, allowing Heathrow to increase its passenger capacity by 30 million per year. Risk management was a major focus, with BAA adopting an integrated team approach and insuring key project risks. Advanced technology like a single 3D project model helped reduce costs by 10%. Lessons learned included the importance of leadership, planning, logistics management, and community engagement.