Influence of ventilation design on the prevalence of anti-microbial bacteria in homes

This project will investigate how contemporary housing design affects the indoor microbiome, and what the effects of this might be on anti-microbial resistance. In the early 19th century, the way that houses were designed led to considerable improvements in public health, largely as a result of improvements in sanitation, but also access to fresh air and sunlight.

In recent years, however, commercial interests and building legislation have largely dictated design issues. During this time the ways that buildings have been designed and constructed has changed significantly, mainly as a response to issues of climate change. Improved thermal performance and increasing airtightness has been able to isolate the building from the external environment. Whilst this will have benefits in terms of reduced carbon dioxide emissions, lower running costs and better comfort, it is becoming increasingly clear that levels of ventilation and consequent standards of indoor air quality (IAQ) are reducing and there is emerging evidence that this might have negative health impacts.

Whilst there are a number of dimensions to IAQ, one area that has not been researched is the prevalence and nature of microorganisms. People - especially vulnerable groups such as the old and very young - spend a great deal of time in the home, and so any change to the indoor microbiome may significantly affect occupants' health. There is a concern that isolation from the outside environment may reduce diversity and result in the proliferation of harmful microorganisms, including those that have anti-microbial resistance.

This study aims to close this gap in knowledge by undertaking an assessment of contemporary housing to determine the ventilation characteristics and relate this to the presence and nature of microorganisms in the home, with the specific aim of identifying factors that would impact the presence and proliferation of anti-microbial resistant microorganisms. It anticipated that this could lead to changes in the way that we design buildings, in particular ventilation provision, and the project will aim to address this through a programme of academic, industry and public dissemination.


This study has the potential to change the way that housing is designed, and consequently affect occupant health. Specifically, the study could lead to the development of 'bio-informed' design that reduces the risk of AMR (and other health factors) in homes. Given that housing is a ubiquitous built form, the impacts of this could be very significant.

The study will begin to develop a more robust evidence base for the health effects of ventilation in homes. This can be used to develop design guidance for architects and clients that can inform design. It also provides a basis for revised legislation on building standards - the present regulations state that homes should not adversely affect the health of occupants. However, there is no health evidence or consequent metrics available to support this.

The information produced by the study can be used by designers and clients to identify design standards and best practice. The identification of health impacts (and costs) of design decisions helps to establish a case for improved design quality and investment to produce better outcomes. This could lead to use of design as a preventative measure, to reduce health costs and risks. The study has the potential for significant impact through the contribution to an evidence base for building standards for ventilation. There are precedents for this in terms of other buildings such as hospitals.

The design of housing was used to improve health in the early 19th century, and this work could contribute to a contemporary knowledge base here which would facilitate improvements in health and well-being. If the study can identify associations between housing design, ventilation and AMR, then there will be a significant public health and clinical impact. The study will provide initial evidence as to whether homes are likely to be a significant community reservoir for AMR bacteria. If we find that this is the case, the outcomes have a substantial influence on future AMR policy. Impacts would be medium to long term and could range from recommendations around ventilation use, cleaning and hygiene, to the use of design to reduce the risk from infection and so reduce reliance on antibiotics.

The outputs of the study will also be used to increase public awareness of ventilation, indoor air quality and AMR in homes, through public dissemination, information sheets, advice to clients and landlords for tenants and owners, and through media - previous work undertaken by both the MEARU and the Leeds investigators has led to BBC news and national newspaper coverage which has had a considerable public impact.

The study will also produce an evidence base for use by key groups and advocates, particularly those concerned with health and well-being issues, e.g. charities for older people, COPD, asthma. It may also be used in clinical and GP diagnosis to identify risks of home environment on the efficacy of drug treatments, risks of re-infections, etc.

Publications and outputs

Dancer, S (2018) What is the Microbiome of the Human Home? Holgate S (2020) The inside story: Health effects of indoor air quality on children and young people.

Holgate S (2020) Environmental Pollutant Exposures and Public Health

McGill, G (2018) What's inside our homes: the impact of energy efficient design strategies on indoor air quality. 

McGill, G (2019) Towards healthy and energy efficient new homes: current issues and future directions.

McGill, G (2018) Indoor Home Environment: UK Perspectives

McGill, Grainne (2020) Home Ventilation Performance in Practice. In: State-of-the-Art ventilation solutions.

Moreno-Rangel A (2020) Indoor Air Quality in Passivhaus Dwellings: A Literature Review. in International journal of environmental research and public health

Sharpe T (2020) Influence of ventilation use and occupant behaviour on surface microorganisms in contemporary social housing. in Scientific reports