In his 15-year career, Mr. Majcen has notched 45 buildings, including a 50-story sprint up the stairs of the Millennium Tower, the tallest building in Vienna.

WSJ: Runners Find Stairways to Heaven Amid Asia's Skyscraper Boom

The 60-acre site is currently undergoing a major transformation and is home to the Glasgow Science Centre, Imax Cinema, the Millennium Tower and Pacific Quay Developments' business park.

BBC: Artist's impression of Pacific Quay bridge

The well-known venture capitalist recalled the incident while sitting on a leather sofa in his staggering penthouse: a newly completed two-bedroom, three-bath 5, 500-square-foot apartment on the 60th floor of the Millennium Tower with views from the Golden Gate Bridge to the Bay Bridge and beyond.

WSJ: Tom Perkins's Penthouse Fit for King