LED lighting upgrade for London’s Square Mile

The challenge

The City of London, also known as the Square Mile, is home to some of London’s most iconic landmarks, including the Bank of England and St. Paul's Cathedral.

In 2018 the City embarked on an LED replacement programme. ​The objective: to improve the quality of life for its workers and residents, by avoiding unnecessary light pollution, over-lighting, excessive glare and inconsistencies in lighting design.

Clients and partners


  • Client

    The City of London

Key project requirements

  • Replace old stock with newer lighting technology.
  • Allow individual control of a lantern and provide the City with a Smart City Network.
  • Ensure the right light, in the right place, at the right time. CCT’s of 4000K were selected for main highways, 3000K for minor roads and 2700K for places of interest and heritage lighting.
  • Ensure that light and darkness are better balanced, meeting both a functional and aesthetic need.

The solution

After an extensive evaluation process where performance and cost were balanced, Kirium Pro street lanterns were successful. Kirium Pro 1 and Pro 2 lanterns have been installed, in both 4000K and 3000K colour temperatures, to provide quality lighting along the major and minor roads around London’s Square Mile. A mixture of column and wall mounted versions have been deployed.

Kirium Pro represents the ideal low maintenance solution for local authorities. Its Diamond+ technology directs the right amount of light exactly where it is needed, efficiently achieving >174lm/W.

In combination with Urban Control CMS and an 80% dimming schedule, the City of London are now saving in excess of 40% in energy. The lanterns performance exceeded expectations, therefore the dimming schedule will be changed to 60% which is predicted to deliver a further 10% in energy savings.

Furthermore, the future-ready benefits of the range are easing the process of rolling out a Smart City Network across the district.

" The City of London is happy to partner with DW Windsor as our lantern supplier for the City’s LED replacement programme. Their knowledge, attention to detail and helpful manner have greatly aided the City with the ordering and delivery of equipment and they have also provided an excellent lighting design service "

Andy Rogers, Mechanical & Electrical Manager

Department of the Built Environment, City of London

Products featured

Projects featuring Kirium Pro