UCL Energy Institute


Physical Characterisation of Buildings

The Physical Characterisation of Buildings Group investigates the empirical energy performance of buildings. We research (hygro)thermal performance and ventilation, applying physics and statistical techniques to both develop methods for the evaluation of the real, observed, thermodynamic behaviour of buildings and to derive a greater appreciation of the performance of the built stock. 
The group’s research addresses energy efficiency improvements, heating decarbonisation, understanding the conditions experienced by occupants and enabling more flexible operation. This supports energy policymaking, improving living conditions, decreasing operating costs and improved energy security.  

Our research interests

The Physical Characterisation of Buildings Group research addresses the in-situ thermal performance of buildings, their components and systems. We measure the characteristics of performance (e.g. energy use, internal temperature, CO2 concentration) to create large datasets and use a wide range analytical tools to derive insights into building performance and the impacts of occupant practices. We also undertake socio-technical research by collaborating with social scientists to deliver both detailed insights and practical solutions.  

Characterising the whole house thermal performance of occupied buildings 

Photo of a person using a thermal imaging camera on a house
The Physical Characterisation of Buildings Group have been at the forefront of the development of new methods to characterise the thermal performance of occupied buildings, spanning the application and development of simple energy signature methods that only require smart meter data, up to complex grey-box models including a range of data inputs, dynamic models and solved via Bayesian statistics.

Decarbonising heating and cooling

Photo of a heat pump attached to the side of a building
Our research aims to support the shift from fossil fuel boilers to decarbonised heating and cooling, provided by heat pumps, by addressing the whole system performance: the heating plant, heat distribution, fabric, controls and occupants.

Elemental thermal performance 

Thermal image of many buildings in a city
It is important to better understand the thermal performance of building elements to provide insights into how they may be improved, or accounted for. Our research has focussed on the development of new methods to characterise elemental performance, primarily using dynamic models and Bayesian statistics.  

Ventilation and indoor environmental quality

Photo of ventilation on the side of a building
Our research into this field addresses the trade-off between ventilation and energy use, aiming to understand the relationship between the ventilation observed in real buildings, indoor environmental quality and energy use. It is important to better understand these relationships, to enable the decarbonisation of heating and cooling in buildings, while ensuring those buildings are safe and healthy. 

Enabling the flexible operation of heating

Photo of a digital thermostat on a wall
A huge shift in the energy system is taking place due to the electrification of heat and transport, and shift to renewables. More flexibility needs to be built into demand to enable these changes. Our work in this area aims to explore how buildings may be operated more flexibly, for example by limiting heating within peak hours, whilst maintaining good internal conditions for occupants.    

Research with impact

The Buildings Theme and Physical Characterisation of Buildings group focus on delivering impact through research to support decarbonisation and improved quality of life. Our research is highly applied and involves working with partners in government (e.g. the Department of Business Energy and Industrial Strategy), industry (e.g. PassivUK) and non-governmental organisations (e.g. Ofgem, the UK Health Security Agency). Through research and consultancy, we aim to provide a solid evidence base for decision making and tools to enable future insights. 

Photo of a radiator

Boiler oversizing reduces efficiency and increases carbon emissions

Gas boilers dominate domestic heating in the UK and whilst previous our research highlighted the positive impact of condensing boilers on emissions (and subsequently costs), recent research has highlighted that scope for improvement remains. Research by the our group won the CIBSE Carter Bronze Medal in 2021 for the best research published in the BSERT journal in 2020 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. The paper also recommended revised guidance and energy performance scores to better reflect boiler efficiency in real homes. 

Read the paper on SAGE journals ►

The airtightness of properties: hitting the target and missing the point

Our team published a series of papers exposing unexpected results in the airtightness test results for new build properties in England and Wales, undertaken to check their quality. These revealed issues with the current testing and lodgement system that cause a distortion to the reporting of accurate results; the relation between construction and airtightness; and the lack of clear relationship between airtightness test results of new homes and their ventilation strategy. This latter research resulted in the award of a Napier Shaw Bronze Medal by the Chartered Institute for Building Services Engineers (CIBSE) for the highest rated article in the Building Services Engineering Research and Technology (BSERT) journal 2019. This work is also directly cited as evidence in the government response to the consultation on the Future Homes Standard, identifying that the use of ventilation strategy must be related to the airtightness of the fabric and subsequently leading to a revision of the updated Building Regulations.

Read the paper on SAGE journals ►

Characterising whole house thermal performance

Our research has made a sustained contribution to the development of new methods to characterise the thermal performance of occupied dwellings, initially through the IEA EBC Annex 71: Building energy performance assessment based on in-situ measurements; then through the UK government Smart Meter Enabled Thermal Efficiency Ratings (SMETER) Innovation Competition, where UCL formed part of the Technical Assessment Contractor; and latterly through leading the Green Homes Grant – SMETER project.

Find out more about the SMETER project ►

Our projects

The Physical Charactisation of Buildings group has contributed to a range of different projects to undertake high quality original research into the energy performance of buildings. We work with colleagues across the UCL Energy Institute researching Energy & Buildings, and collaborate with researchers in other institutions to develop scientific, policy and socio-technical insights.

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Energy performance of buildings in teaching

students in an energy modelling lecture

The Physical Characterisation of Buildings group are closely engaged with teaching the Smart Energy and the Built Environment MSc, also acting as dissertation tutors for the MSc Energy Systems and Data Analytics. We aim to relate our research to taught material, providing cutting-edge lectures and tutorials that are both engaging and relevant to students.  

We also support and work closely with the EPRSC Centre for Doctoral Training in Energy Resilience and the Built Environment, teaching and supervising students in addition to contributing to the wider training programme.

Smart Energy and the Built Environment MSc

The physical performance of buildings and the systems within them, such as heating plant and ventilation, is central to understanding how the built environment can transition to smarter operation, set within the context of practice and policy: we aim to bring these aspects to the Smart Energy and the Built Environmeny MSc degree. 

All modules within Smart Energy and the Built Environmeny MSc are relevant to the Physical Characterisation of Buildings group’s work, but in particular Fundamentals of Smart Energy and the Built Environment and Smart Distributed Energy Systems relate closely to our interests and research.

We support a wide range of dissertations, primarily focussed on the physical performance of buildings. These include the analysis of datasets to better understand building performance, derive the metered energy saving of a retrofit and to determine how a heat pump is working. Students may measure energy use or other factors such as ventilation rates, or explore secondary data and we aim to tailor the research to students’ interests and skills. Previous dissertations include “Physical constraints on the energy flexibility of homes with heat pumps” and “Developing a linear regression model for prediction of UK residential energy consumption”. 

View Smart Energy and the Built Environment MSc in the UCL Prospectus ►

Doctoral Research (PhD)

Our group is closely engaged with the EPSRC Centres for Doctoral Training in Energy Demand (LoLo) and Energy Resilience and the Built Environment (ERBE); Cliff Elwell is the Deputy Director and Jenny Crawley the Academic Manager of these CDTs. Our team is engaged in all aspects of these programmes, including teaching courses, providing training and supervising students. We additionally seek to supervise non-CDT students who share our research interests. Current students:

Doctoral research relating to Physical Characterisation of Buildings

  • Minnie Ashdown - Understanding the variability of air infiltration in buildings through statistical analysis of CO2time series data and a probabilistic conservation law
  • Laurence Childs - Data driven approach to identifying building retrofit pathways
  • Cairan Van Rooyen - The relationship between ventilation practices, indoor air quality, noise and overheating, and their impact on health
  • Adria Martin Vilaseca - Transforming home heating: How smart platforms can help users navigate new everyday experiences and trade-offs
  • William Markiewicz - Data Driven Approach to Modelling the Resource Footprints of Live Data Streams in Digital Twins

Our researchers

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Jenny Crawley
Research Associate
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Cliff Elwell
Professor of Building Physics
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Virginia Gori
Lecturer in Energy and Buildings
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Clare Hanmer
LoLo & ERBE Academic Manager and Research Fellow in Buildings and Energy
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Frances Hollick
Research Fellow in Physical Characterisation of Buildings
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Jez Wingfield
Senior Technician – Physical building Performance
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Minnie Ashdown

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Laurence Childs

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Cairan Van Rooyen