Publication - Independent report

Coronavirus (COVID-19): care home outbreaks - root cause analysis

Published: 3 Nov 2020

Findings of the rapid review of COVID-19 outbreaks in four care homes, including a list of recommendations based on risk factors that were found to be common in at least two of the homes.

Coronavirus (COVID-19): care home outbreaks - root cause analysis
14. Built environment issues

14. Built environment issues 

Care homes historically have accommodated frail, older residents, however many residents now have additional and increasingly complex needs, and we heard several times of the challenges associated with this, such as residents with dementia who would 'walk with purpose', and the resulting ability of care staff to ensure contact with surfaces was hygienically managed. Key issues have emerged in the pandemic which indicate considerations for repurposing space and responding to the challenges posed by the need to limit virulent disease transmission within the built environment. The extent to which latent design features impact on the ability to limit disease transmission varies between care homes, however in each care home engaged with throughout this review, environmental factors were an important consideration.  

The extent to which homes were able to fully incorporate guidance in relation to social distancing, PPE storage and availability, separation/ isolation and staff cohorting was variable and dependent on the design of the home. Additionally, the key issues of design, ergonomics, communal spaces, corridor width and shared shower and bathing facilities, together with the complex nature of the residents' conditions, made the provision of effective isolation challenging. We heard of some unintended consequences of changes to practices in the built environment, such as kitchen staff delivering meals to resident's rooms because they were in isolation that unwittingly resulted in further transmission risks. We heard of circumstances in care homes where although toilet and hand-washing en-suite facilities were available, there were shared shower and bathing facilities, some of these had no windows for natural ventilation, one relied on electric extraction fans. Small confined spaces with no natural ventilation present a high transmission risk. One care home described that a two hour timeframe between residents using the bath or shower is enforced to reduce the risk of transmission, supplemented by enhanced cleaning regimes.

Ventilation was not considered as a control measure in any of the homes we reviewed and is not a focus in extant UK COVID-19 IPC guidance; only recently has the Centre for Disease Control (CDC) (October 2020)[20] and the World health organisation ( WHO) (July 2020)[21] recognised the importance of longer range aerosols as a potential route for transmission, whilst recognising that the main route remains droplet and short range aerosol. Any situation in which people are in close proximity to one another for long periods of time increases the risk of transmission. Indoor locations, especially settings where there is poor or no ventilation, are riskier than outdoor locations. The 3Cs for high risk of transmission outlined by WHO include: Crowded places with many people nearby, Close-contact settings, especially where people have conversations very near each other, Confined and enclosed spaces with poor ventilation. Many care homes are high risk settings in this context, and the built environment is a key infection prevention and control measure is key for mitigating risk of outbreaks and impact of these.

Ventilation may become increasingly important in this context as winter develops, therefore adaptation of spaces and dilution of air is dependent on natural ventilation (window opening). UK SAGE[22] has recently developed guidance for consideration of this and this should be used to inform care home best practice principles, such as not recirculating air if it can be avoided and ensuring rooms are adequately ventilated to mitigate the risk of transmission.


  • Infection prevention and control specialist support for individual care homes is required when considering the built environment and risk assessment
  • Risk assessment inclusive of advice relating to the built environment covering areas such as fire and falls is required, to ensure that no unintended consequences of changes in the built environment due to IPC measures, are present.
  • Ventilation guidance should be considered nationally to share general principles to mitigate transmission risks re aerosols over the winter months in care homes