The Co-operative Insurance Tower, more commonly known as the CIS Tower or CIS building, is the second-tallest building in Manchester, England. Measuring 387 feet (118 m) tall, the glass roofed building on Miller Street is home to Co-operative Financial Services. The Tower was built in 1962 and overtook the Shell Centre as the tallest building in the United Kingdom. It would retain the title for only a year, being replaced by the Millbank Tower in Central London. The architects were Gordon Tait and G. S. Hay.
The building recently underwent a major facelift as it was clad in photovoltaic panels, the UK's largest solar power project to date, which will generate 180,000 kWh per year, or, on average, 21 kW. (Electricity usage per capita in the UK is about 5,000 kWh per year.) In 2006, the tower lost its title as the tallest building in Manchester to the Beetham Tower which is 554 ft (169 m) tall.
The Tower originally was clad with millions of mosaic tiles, inspired by the buildings of New York such as the Seagram Tower. However, pollution and numerous repairs had rendered the once shimmering tiles a dull grey colour, a factor in the decision to cover the building in solar panels.
The Co-operative Insurance Tower was clad in PV panels at a cost of £5.5 million and started feeding electricity to the National Grid in November 2005.