W2UP13 – Whole-house ventilation systems in low energy UK housing; investigating user acceptance of innovative technologies
22nd October 2015 Carrie Behar

Whole-house ventilation systems in low energy UK housing; investigating user acceptance of innovative technologies

Carrie Behar, UCL

Project Title:

Whole-house ventilation systems in low energy UK housing; investigating user acceptance of innovative technologies


An effective and widely adopted mechanism for reducing the energy consumed in buildings is to increase airtightness and reduce ventilative heat losses through the building envelope. The challenge of ensuring sufficient ventilation whilst maximising energy efficiency is being addressed by the construction industry though the provision of purpose-provided ventilation, which can be mechanically or passively operated. A gap in the knowledge exists regarding the performance and acceptance of these systems in practice.

In this thesis, a case study approach is adopted to investigate three ventilation systems, namely passive stack ventilation (PSV), mechanical extract ventilation (MEV) and mechanical ventilation with heat recovery (MVHR). Although these innovative technologies have great potential, the identification of a performance gap between predicted and actual building energy consumption has led academics to question whether technological solutions alone can solve the problem of decarbonising the UK’s housing stock?

The UK’s housing stock is responsible for almost a third of total UK CO2 emissions, which need to be reduced by 80% to fulfil the obligations of the Climate Change Act (2008). Yet buildings serve an essential purpose to protect and nurture society; needs which must not be compromised at the expense of meeting ever-pressing energy targets. In particular, we spend a large portion of our time at home, an environment which should be kept thermally comfortable and free of pollutants.

The research problem is addressed via a sociological investigation of the actors involved in the process of designing, specifying, installing and using the ventilation at each of the sites.These actors include architects, contractors, landlords and residents.

Fieldwork was conducted in 2012 and 2013. 30 semi-structured interviews were carried out with a range of actors involved at each site. Resident interviews were conducted in in their homes, and, where possible, included a walk-through of the property. The interview data are supported by analysis of design and construction documentation. An interpretive and inductive framework is being used to analyse the collected data, using empirical data as the foundations from which to generate theoretical explanations.

Preliminary findings indicate a lack of understanding of how energy efficiency ventilation technologies (are supposed to) work. Surprisingly, no connection was found between this level of awareness and user comfort and satisfaction. Instead, a resident with no expert understanding of the system was able to appropriate the technology in a way that she understood. The user and the technology seem to be mutually adapted to one another, because she was socially embedded in the community and therefore able to receive the help she needed to settle into a routine of environmentally positive practices. On the other hand, a potentially motivated resident is in a state of extreme dissatisfaction with her home due to lack of support from her landlords. She cannot understand the purpose of the ventilation; it doesn’t seem to be working and so she has rejected the technology.

Ongoing analysis suggests that the experience of living in a low energy dwelling and interacting with new ventilation technologies is influenced by a set of complex and interconnected social, spatial and technological aspects. Simply providing residents with more information or more intuitive systems is unlikely to prevent shortfalls in dwelling performance. Instead a more holistic approach is recommended for the successful integration of energy efficient ventilation technologies into the UK’s housing stock.

The original contribution to knowledge of this thesis is to present empirical evidence about why, how and to what extent residents in the UK adapt their practices when they live with energy efficient ventilation systems, and to critically evaluate the circumstances where such technologies are rejected or misused by users. This information is required if we are to ensure that the shift to continuous whole house ventilation in UK housing results in the predicted and required energy savings, without compromising occupant health and comfort.


1. Regulations are changing the way we ventilate our homes:

Increased airtightness is an effective mechanism for reducing ventilative heat losses in dwellings.
New homes are constructed with purpose-provided ventilation, to address the challenge of ensuring sufficient ventilation whilst maximising energy efficiency.
The need to reduce energy demand in dwellings is driving increasingly strict building regulations.
Consequently, we are having to change the way we ventilate our homes.
A shift in ventilation systems, strategies and practices is expected, from traditional naturally ventilated homes to dwellings incorporating whole-house systems, technologies once found exclusively in non-domestic buildings.
2. Innovative technologies pose new challenges:

People’s ventilation behaviour can have an impact on energy use and indoor air quality (IAQ) and may be responsible for the ‘performance gap’ between predicted and actual building energy use.
Residents are often unaware of the benefits of whole-house ventilation, and of the potential energy and health implications related to their use.
Research indicates that some dwelling occupants use windows and ventilation technologies in different ways to those intended by the designer; people have been found to open windows and trickle vents while the heating is on, and even to disable mechanical ventilation systems.
Most ventilation systems require maintenance which users are failing to carry out properly.

Project Team

Carrie Behar
Tadj Oreszczyn
Ben Croxford
Lai Fong Chiu


Conference poster

Whole-house ventilation systems in low energy UK housing; A user perspective on innovative building services technologies

Presented at CIBSE Technical Symposium, 2013.

Ventilation Systems in Low-energy UK Housing; A user perspective of behaviour and ‘adaptability’

Poster presented at Behave Conference on Energy Efficiency and Behaviour, 2012.



LoLo Annual Colloquium 2013 Poster

Poster presented at the 2013 LoLo Colloquium: ‘Ventilation in energy efficient UK homes Understanding users’ experience of new technologies’

LoLo Annual Colloquium 2012 Poster

Poster presented at the 2012 LoLo Annual Colloquium, where guests included members of the CDT advisory board, adademic colleagues and industry stakeholders. Poster title: How can we ensure that energy efficient ventilation technologies are integrated into the UK’s housing stock in a way that is acceptable to residents?

LoLo Summer Event 2012 Poster

Poster presentation at LoLo annual summer 2 day event in Cambridge. Poster summarises research area and presents some inital findings.



LoLo Annual Colloquium 2013 Project Presentation

Presented PhD project at LoLo Annual Colloquium. ‘Whole house ventilation in low energy housing; how do people adapt to living with new ventilation technologies?’

LoLo Annual Colloquium 2013 Paper Presentation

Presented prizewinning paper at LoLo event.

Ventilation in energy efficient UK homes; Understanding users’ experience of new technologies

Presented at ‘Building Performance: The Bigger Picture’ – UCL Energy Institute Masterclass with Bill Bordass and Adrian Leaman.

Investigating Ventilation Technologies in Low Energy Homes

Short presentation delivered at UCL Anthropology event:’Sustainability: Concepts & Materials’. This was a student conference hosted by the UCL Anthropology sustainability reading group.