Vatican City, the Empire State Building, and the Sydney Opera House have all employed low-energy solutions in one form or another in recent years. “High profile projects can highlight the importance of retrofitting and cause people to think about installing renewable energy systems on the micro level,” says John Alker, director of policy at the UK Green Building Council.
While retrofits of historic structures require sensitivity, particularly to building façades, improving insulation, replacing windows, and making air conditioning more efficient usually have negligible impact on aesthetics. Tower Bridge in London is one of the latest iconic retrofit projects. The 100-year old span will be outfitted with an LED lighting system that will reduce energy consumption by 40%.