KJ Tait

St John’s College Student Hub, Cambridge

KJ Tait were appointed by St John’s College to carry out an assessment on how to increase the daylight levels within the student hub.


The project consisted of the provision of:


  • Average Daylight Factor (ADF) to all other occupied spaces in accordance with Lighting Guide 5 (LG5).

The objective was to work closely with the Architect on roof options to enhance the existing flat rooflights to provide a more architectural look with the added advantage of additional daylight.


The first option was a very flat cone design which increased the average daylighting from 3% to 4%. However, by remodelling the cones to have an angled top surface, this allowed much more daylight in due to the south facing orientation.


By doing this we managed to increase the average daylight to over 6% which is more than double the existing provision.


According to CIBSE Lighting Guide 5 (LG5) anything over an average daylight factor of 5% is predominantly daylit and artificial lighting will not be required.