College Lake Wildlife Visitor Centre

Principal Investigator(s): Professor Rajat Gupta


Project start: September 2012

Project finish: September 2014

Funded by: Innovate UK

About us

Category: Non-domestic in-use building performance evaluation.

Objective: Widening our understanding of real energy performance in civic buildings.

The building forms the main visitors centre at the College Lake nature reserve, run and managed by the Berks, Bucks and Oxon Wildlife Trust and gives vital teaching and office spaces for the Trust to communicate its message to the public.

The scheme is designed to a high environmental agenda and far exceed the building regulations. The building has been designed to be low energy based on ‘fabric first’ approach, focussing on elements such as airtightness, earth-retaining structure, high insulation levels, innovative rammed chalk material for internal walls, solar shading, thermal mass, stack ventilation system combined with 'high level' glazing and low energy fittings. The annual CO2 emission rate from the EPC is 23.37kg CO2/m2/year which is 50% less than the notional building of the same category.

This BPE study will verify the extent to which the design aspirations are met in reality and the reasons for the gap.

The areas of focus are (1) Effectiveness of ‘fabric first’ passive approach (2) Energy use compared to CIBSE, industry benchmarks using TM22 (3) Comfort criteria in office, meeting spaces with reference to summertime overheating (4) Performance of air-source heat pumps (5) The effect of the specified construction systems on moisture levels (6) The impact of the users on energy management and use.

Indoor view of the building, showing windows and roof


Rajat Gupta

Professor Rajat Gupta

Professor of Sustainable Architecture and Climate Change, Director of OISD and LCB Group

View profile


  • Energy data was collected over two years and two heating seasons. Techniques included a review of handover process and commissioning, assessment of natural ventilation strategy, and addressing supply chain issues as mentioned in the suggestions.
  • Detailed assessment of annual energy consumption over 2 years using CIBSE 22 procedures.
  • Long-term monitoring of temperatures, humidity and CO2 levels, to determine technical performance, spot checks and measurements was be undertaken in different seasons, using thermography, smoke pencils and true power meters.
  • Walkthrough surveys took place to identify any wastage of energy. This was triangulated with feedback from staff (and visitors) using BUS questionnaires to ascertain whether needs were met and issues with usability of controls.
  • Structured interviews with management investigated reliability, maintenance and maintainability.

An view of the Visitor Centre roof


Findings from the study were captured through interim and final reports, categorising recommendations on costs, impact and disruption caused. Recommendations were then fed back to the occupants, building owner, operator, design and building team.

Project details

Funded by:

  • Innovate UK (formally known as Technology Strategy Board)

Project Partners:

  • A+G Architects
  • Berks, Bucks and Oxon Wildlife Trust
  • Institute of Sustainability
  • Edgar Taylor contractors

  • Total project value: £58,290
  • Income to OBU: £40,250


  • Gupta, R. and Kapsali, M. (2015). Leading-by-example: comparative evaluation of the actual performance of two low-carbon community buildings in UK, Proceedings of 31st International PLEA Conference, 9-11 September 2015, Bologna, ITALY