UCL Energy Institute

Prof Cliff Elwell

Prof Cliff Elwell

Professor of Building Physics

Bartlett School Env, Energy & Resources

Faculty of the Built Environment

Joined UCL
18th Oct 2010

Research summary

Cliff’s research interests build on his experience in physical sciences, physics and materials science, and in data analysis. He has an active interest in applying the tools and techniques – measurement, experimental design, statistical methods etc – of these disciplines in the energy demand domain.

Cliff’s core interest is in the measurement of energy use, and parameters related to it, to characterise the performance of buildings, building elements and systems. A physicist, his research includes understanding ventilation, the thermal performance of buildings and heating/cooling systems, combining physical principles with statistical analysis, including frequentist and probabilistic methods. He leads the Physical Characterisation of Buildings team, who undertake monitoring campaigns, develop physically informed models, undertake analysis and relate the outcomes to the complex socio-technical factors that affect building performance, and policies and practices that may support reductions in carbon emissions. Topics include:

  • characterising the thermal performance of occupied dwellings from in situ data;
  • the development of a novel technique to characterise the thermal performance of building elements utilising Bayesian analysis;
  • investigation into the distribution of airtightness test results for new UK dwellings, and how they relate to targets set for compliance purposes;
  • investigation of the thermal performance of floors and walls, and the unintended consequences of retrofitting;
  • estimation of the efficiency improvement associated with the replacement of conventional with condensing boilers in the building stock from national datasets.

Recently Cliff has contributed to a range of projects, including:

  • UK Centre for Research in Energy Demand Solutions (CREDS) (EP/R035288/1), leading sub-theme 1.2 “Disrupting the system performance and deployment of low energy/power retrofit and new build – through digital, business and market innovation”.
  • BEIS Green Homes Grant - Smart Meter Enabled Thermal Efficiency Ratings (GHG-SMETER) project (PI), investigating the application of these methods for policy evaluation and the change in heat transfer coefficient (HTC) observed following retrofit under the GHG.
  • BEIS Smart Meter Enabled Thermal Efficiency Rating (SMETER) Innovation Competition as part of the Technical Assessment Contractor (with Loughborough University (PI), Leeds Beckett University and Halton Housing).
  • IEA Annex 71: Building energy performance assessment based on in-situ measurements.
  • Centre for Energy Epidemiology, leading the Cliff led the Metrology Theme, researching whole house thermal characterisation.    

Cliff has won two medals for best papers in the Building Services Engineering Research and Technology (BSERT) journal from the Chartered Institute of Building Services Engineers (CIBSE). Napier Shaw Bronze Medal in 2020, with Jenny Crawley and Jez Wingfield, awarded for a paper showing a lack of clear relationship between ventilation strategy and airtightness, leading to revision of the Building Regulations. Carter Bronze medal in 2021 with George Bennett for a paper illustrating that the widely adopted practice of oversizing a gas boiler has significant impact on its energy use and the internal conditions experienced and recommending revised guidance and energy performance scores to better reflect boiler efficiency in real homes.

Teaching summary

Cliff is Course Director of the Smart Energy and the Built Envrionment MSc. He teaches the Smart Distributed Energy Systems module.

Cliff is Deputy Director of the EPSRC Centre for Doctoral Training in Energy Demand (LoLo) and the CDT in Energy Resilience and the Built Environment (ERBE). His role centres on delivery of the core goals of the CDT, primarily to promote and develop excellence in the provision of doctoral training, to undertake world class research on energy demand and the built environment and to deliver first class researchers into the workforce. More information on the centre is available on the LoLo webpage (http://www.lolo.ac.uk/).

Cliff supervises PhD and masters students on a range of topics related to his research interests.

Cliff has previously been Course Director of the MRes EDS and Departmental Graduate Tutor (Research) for the Bartlett School of Environment, Energy and Resources (BSEER), overseeing and providing support to the School's MPhil, PhD and EngD students and their supervisors.


Institute of Education
Other Postgraduate qualification (including professional), ATQ03 - Recognised by the HEA as a Fellow | 2014
University of Cambridge
Doctorate, Doctor of Philosophy | 2003
University of Cambridge
Other higher degree, Master of Natural Science (Honours) | 1998


Cliff Elwell is Professor of Building Physics at UCL Energy Institute, where he leads the Physical Characterisation of Buildings group, co-leads the UCL-Energy Buildings Theme, Course Director of the Smart Energy and the Built Environment MSc, and is Deputy Director of both the EPSRC Centre for Doctoral Training in Energy Demand (LoLo) and the CDT in Energy Resilience and the Built Environment (ERBE).

Cliff’s research interests are primarily in building physics, focussing on characterising the performance of buildings, building systems and building elements through in situ monitoring and analysis using a range of methods. His work often features the application of physically informed models and Bayesian analysis.