King's College Chapel, University of Cambridge

The 438 new photovoltaic panels on the roof of the King’s College Chapel, Cambridge, marks a historic milestone for British architectural heritage.

An aerial view of a historic building and green spaces

Key information


Caroe Architecture


King's College, University of Cambridge



Year of Completion




King's College Chapel is a Grade I-listed building built between 1446 and 1515 and is considered to be among the finest gothic structures in Europe.

We worked with the college to develop a strategy to decarbonise its operations by 2038, reducing its carbon emissions by more than 23 tonnes each year. The new panels, combined with existing panels installed on the Wilkins Building and Old Garden Hostel student accommodation, will meet the chapel’s energy requirements and reduce the annual electricity demand of the college’s main site by approximately 6%, reducing the college’s reliance on the National Grid.

In the long term, technical analysis has assessed that – even after factoring in the payback of the embodied carbon of the panels themselves – the lost opportunity cost of not implementing the proposed PV panels would equate to the emission of approximately 410 tonnes of CO2 between now and 2050, independently of any electrification of heating demands.

Milestone project

The panels are part of the renovation of the 1950s lead roof of the chapel, which was no longer watertight. The college recognised a once-in-a-generation opportunity to install the PVs, as the chapel roof is the single largest potential opportunity for renewable electricity generation on the main college site.

Arrays of photovoltaic panels have been fixed to both of the north and south slopes of the chapel roof and will generate an anticipated 123,000 kWh/y which will feed into the college’s on-site electricity supply. The total potential peak output of the panels is 100 kWp.


of energy requirements of chapel met by PVs

123,000 kWh

generated per year

A worker walking crossing wooden bridge over the cathedral Cathedral roof with multiple spires reaching towards the sky

© Barnes Construction

"The need to replace the lead roof presented a once-in-a-lifetime opportunity to implement the largest PV array possible in the main college site. Rigorous analysis provided an evidence base to support the very sensitive design proposal which ultimately resulted in a successful planning application for this beautiful and remarkable Grade I-listed building. The system is now fully functional and has started its job of reducing carbon emissions and the consumption of grid-supplied electricity." 

Portrait photo of man in white shirt against a black background.

Director, MEP Engineering