The Principal Tower, a 50-story mixed-use structure, is a striking addition to London's skyline. Its unique design, featuring three shapes of varying heights arranged in a cruciform, posed significant challenges during construction. WSP, the consultancy firm overseeing the project, had to navigate complex logistical constraints, including a nearby railway and Victorian-era tunnels, while ensuring structural stability and adhering to strict design codes. Leveraging innovative technology and meticulous planning, WSP successfully completed the project within budget and schedule.