CPD module: Using data to make decisions on indoor air quality

Poor indoor air quality has long been recognised as a major health risk, linked to asthma, heart disease and even cancer. Social landlords are under increasing pressure to reduce these risks, especially those posed by exposure to damp and mould in their homes.

Under Awaab’s Law (see box), from October 2025, housing providers will have a legal duty to investigate and fix dangerous damp and mould. In addition, landlords will need to demonstrate that urgency of intervention has been prioritised and the remediation has been completed in an appropriate timeframe.

Landlords’ decisions to improve indoor air quality can be guided by the data they hold, collect, and analyse. This CPD module, in association with home safety device specialist Aico, will examine how data can provide insights and drive decisions for social landlords as they face this new legal duty and seek to improve indoor air quality and the lives of those who occupy their homes.

There are multiple biological, chemical and physical agents in the home, which can present health risks to residents. Sources of poor indoor air quality range from cigarette smoke, to damp, mould, outdoor air quality (in urban areas), gas cookers and boilers and, in some parts of the country, radon gas (see box).

This module’s main focus will be on damp and mould and radon gas, given the significant health risks these pose if left unchecked. These can all be measured and better managed by analysing data from sensors placed in residents’ homes.

The primary causes of poor indoor air quality are a complex combination of property use, household vulnerabilities, lack of knowledge, financial capacity and the quality of the building itself. Adding to these complexities, housing providers manage a range of property types from different eras and with differing heating, insulation and ventilation characteristics – and each type of property might perform differently in relation to indoor air quality.

Damp and mould in homes is clearly linked to humidity and air temperature, as well as the thermal quality of the property, leading to condensation. In some cases, excess humidity is caused by water entering homes through a variety of routes, including breached damp courses, leaky roofs and front or rear doors.

But in most cases, damp is caused by condensation created within the home where humidity levels have been elevated due to occupancy levels or other circumstances, such as pet ownership. Vivarium tanks for exotic pets like lizards, for example, can introduce additional moisture into a home. Condensation problems are also linked to temperature levels and insufficient ventilation.

In some parts of the country, radon gas permeates through people’s homes. There are quite high levels in parts of Cornwall where Coastline Housing is based, along with Bristol, areas of Wales, Cumbria and parts of the Peak District. A map of areas with significant levels is available from Public Health England.

Poor indoor air quality affects health and can cause disease or even premature death. It is linked to allergies, asthma, chest infections, other respiratory diseases, low birth weights and even cancer. Children growing up in homes with mould are up to three times more prone to coughing and wheezing, according to the Chief Medical Officer’s Annual Report 2022.

People exposed to poor indoor air quality may experience higher instances of cold and flu-like symptoms. Some may be even more susceptible to such health problems because they have weaker immune systems due to other underlying health conditions.

Poor indoor air quality is a particular public health concern because we spend around 90% of our time indoors, most of this being at home. Indoor air pollution can also disproportionately affect people with a lower socio-economic status. Lower-income households spend longer in their homes, due to higher levels of unemployment, according to recent research in the International Journal of Environmental Research and Public Health.

Radon gas levels within homes can fluctuate and it is incredibly hard to predict when they will go up and down. Radon produces radioactive particles in the air. This radiation can damage lungs and over a long period cause lung cancer. This makes the use of sensors particularly important to keep track of them. Gas levels can change in response to interventions in nearby homes or new development.

Awaab’s Law was introduced in the Social Housing (Regulation) Act 2023. It requires all landlords to investigate and fix reported health hazards within set timeframes. The law was introduced following the death of two-year-old Awaab Ishak in December 2020. During an inquest, the coroner found that his death was directly linked to exposure to mould in the social home his family lived in, owned by Rochdale Boroughwide Housing.

This law is being introduced in a phased approach, starting in October with a requirement to investigate dangerous damp and mould. This requirement will be later extended to cover more health hazards. In 2026, it will cover excess cold and excess heat, fire and structural collapse, among other hazards.

The third phase of the roll-out is expected in 2027.

Collecting data linked to indoor air quality helps us understand how a property performs and why it is performing that way. People who occupy our homes will all have slightly different habits, such as how they heat their homes, cook or bathe, all of which this data can pick up on. Housing providers are also facing a legal duty to investigate and fix dangerous damp and mould in tenants’ homes, which is an area of particular focus through Awaab’s Law, which comes into force in October this year. This legal obligation is due to be extended next year to cover cold and excess heat as temperatures across the UK continue to rise.

Installing sensors in homes allows us to collect data on levels of humidity, carbon dioxide and temperature. Housing providers should inform tenants and residents what the sensors they are installing are detecting and how the data can be used to improve the performance of homes.

Humidity and temperature are key measures linked to the prevalence of damp and mould. High moisture in the air increases the chance of mould growth, and lower temperatures, combined with ineffective ventilation, are known to exacerbate this problem.

Carbon dioxide levels can help identify habitual causes of high moisture levels in homes, which can lead to poorer indoor air quality and damp and mould problems. They may show that the presence of pets such as very large breeds of dogs, such as St Bernards, are contributing to damp and mould problems.

CO2 levels are a helpful indicator of occupation, as levels will drop off when the property is vacated and increase when the property is occupied. Subsequent analysis of the data can identify patterns in these levels, which can help inform what kind of interventions may improve poor indoor air quality in homes.

Once these interventions are in place, this data can also show if and how well these interventions are working.

Monitoring devices should be placed away from kitchens, bathrooms and external doorways because they can affect the results. They should be installed where there is some airflow between rooms. One device is sufficient for a one-bedroom flat or a bungalow. However, larger properties may need two or three sensors.

Trends, issues and patterns can be identified in the data if it is collected over an appropriate time period. Ideally, sensors should be installed for a minimum of 12 months as this allows the housing provider to build up a profile of the house’s performance throughout the year. This approach will capture data for the cold months over autumn and winter, but also during the summer when there is a risk of overheating in the home.

Data on humidity, temperature and CO2 levels should be compared side by side and preferably benchmarked with other similar homes to identify any interventions that are needed.

The results of the analysis should also be used alongside the results of a tenant survey. These surveys can identify the location of the damp and mould problem and its scale. They should be carried out alongside conversations with tenants about their heating use, their understanding of how ventilation fans work and discussions about the affordability of utility costs.

Data can be organised into dashboards and run through analysis tools to pinpoint whether homes are at a low, medium or high risk of moisture and humidity.  The results of the analysis can then be used to identify appropriate interventions to improve the performance of tenants’ homes.

• Damp and mould
• Radon gas
• Cleaning products
• Cigarette smoke
• Poor-quality outdoor air

Data on indoor air quality can be used by housing providers to inform longer-term housing management plans.

Sensors can be installed reactively in homes where there are reported damp and mould problems to help diagnosis and provide better-informed decisions. They can also be used proactively to pinpoint wider problems with particular types of homes. For example, sensor data from a small number of properties with damp and mould problems may point towards potential problems in other homes of a similar type.

If three homes in a group are shown to have a damp and mould problem, landlords should consider whether to survey the whole group. They might want to check whether the extraction fans are working properly and whether the tenants have noticed damp and mould.

At Coastline, our tenancy and housing teams have been looking at our technology to see how it could be adapted for wider use. For instance, data collected to measure indoor air quality has been adapted within Coastline Housing to help with our fuel poverty strategy. Sensors have also been installed in new build properties to help customers understand their energy usage. They are used by our damp and mould team who refer cases to the tenancy team if they identify tenants who are at risk of damp and mould in their properties because they are struggling to pay their heating bills.

Data analysis shows where tenants are not turning on their heating during the colder months, which may be a sign that they are in financial distress and are struggling to pay their heating bills. We can offer these tenants sustainability payments to help them cover the cost of heating through the colder months. As well as keeping their homes warm, this will reduce the risk of damp and mould in their homes.

The use of indoor air quality monitoring can provide landlords with strong proof that they are complying with the first two planned phases of Awaab’s Law. From October this year, all social landlords will have to investigate and fix damp and mould in their homes within a set period. In 2026, the government plans to expand the requirements of this law to cover a wider range of hazards, including excess cold and heat.

Indoor air quality monitoring will not only help pinpoint and remedy damp and mould problems in tenants’ homes, it will also timestamp any interventions put in place to tackle these problems and how they worked. This will help housing providers to take any further measures they need to tackle poor indoor air quality linked to these health hazards in their properties. It could also provide proof in disrepair claims of the actions landlords have taken to comply with the requirement to tackle these health hazards and how effective they have been.

This data will also help landlords meet the later requirement to ensure tenants’ homes are not subject to excess cold and heat and will help build heat profiles which could pinpoint problems in heating systems.

• What are the sources of poor indoor air quality in your homes?
• What data do you have available to monitor indoor air quality in your homes?
• To what extent is this data and any methods of analysis you use able to inform your decisions on fixing and preventing health problems linked to poor indoor air quality?
• How could you adapt your data collection methods for monitoring indoor air quality to other uses in your organisation?
• Do you have the data you need to investigate, fix and evaluate interventions used to reduce health hazards related to indoor air quality in order to ensure compliance with Awaab’s Law?

Poor indoor air quality is linked to a range of public health problems, including allergies, respiratory illnesses such as asthma, and cancer. There are multiple sources of poor indoor air quality, including damp, mould and radon gas. The collection and analysis of data on key markers such as humidity, temperature and carbon dioxide levels can help housing providers pinpoint problems with the performance of homes and design interventions to remedy them.

Data collection devices can be installed reactively in response to tenants’ reports of damp and mould, but also proactively to pinpoint additional homes which may be at risk. Air quality data can also be adapted for wider uses, such as to identify people who may be struggling to pay their heating bills.

The phased introduction of Awaab’s Law from October will put increasing pressure on housing providers to investigate and fix health hazards related to poor indoor air quality, such as damp, mould and excess cold and heat.

Next, answer the questions below. Get all the questions correct and you will receive a certificate confirming your award of 30 CPD minutes within 10 working days via email. Get any questions wrong and you can retake the test by refreshing your web browser.

• UK government, Chief Medical Officer’s Annual Report 2022: Air pollution
• National Housing Federation, What is Awaab’s Law?
• UK Health Security Agency, UK maps of radon
  

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