Latest News

Data for Damp and Mould

How can social housing providers rapidly assess their whole stock for the risk of damp and mould?

The Health Risk Prediction service from Parity Projects assesses a clients housing stock data – whether its complaints, monitoring or survey data – and determines risk levels across all homes to help landlords meet their legal obligations to address the risk of damp and mould.

WHY TACKLE Damp and mould?

Last year the Government published its guidance to landlords on the health risks of damp and mould. It is a direct response to the Coroner’s report on the tragic death of 2-year-old Awaab Ishak in 2020, due to mould in his family home.

In addition to underlining the legal standards on damp and mould in rented homes, the report highlights that landlords should not blame damp and mould on tenant behaviour. They must take any reports seriously, and address the causes whether that is through improvements to structures or ventilation.

We’ve been talking to our clients about the causes of damp and mould, solutions and how Parity Projects’ Health Risk Prediction service can help assess risk across the stock.

Causes of Damp and mould in SOCIAL HOUSING

Poor Ventilation

One of the most common causes of damp and mould in social housing is poor ventilation. When indoor air cannot circulate properly, excess moisture accumulates on surfaces, creating ideal conditions for mould growth. Kitchens and bathrooms are particularly vulnerable areas due to the high humidity they generate.

Landlords can install or repair extractor fans in kitchens and bathrooms, or install whole house ventilation systems. Our clients reported tenants are generally positive about centralised ventilation once installed, provided consideration is given to noise and any slight cooling effect from inlets. However, we also hear of refusals to Government-funded insulation installations where tenants do not want the accompanying ventilation as it requires undercuts on doors or trickle vents. The sector is learning the time required to engage tenants on some of these elements, time that is just not available under publicly-funded programmes.

Building Defects

Structural problems such as leaky roofs, damaged gutters, and poorly sealed windows or doors can allow water to infiltrate the building, leading to dampness. This can be a pervasive issue in older social housing properties, homes with flat roofs and basement flats.

Regular maintenance checks and prompt repairs of any structural defects are essential. Roof maintenance and regular inspections can help prevent water ingress, and landlords can use Parity Projects’ Portfolio service to identify homes with risk factors from their age and built form.


Condensation occurs when warm, moist air comes into contact with cold surfaces, leading to water droplets forming. It often affects windows, walls, and ceilings, creating an environment where mould can thrive. Parity Projects’ clients report two particular risk factors: single-glazing and cold spots in bedrooms where walls meet the roof.

In addition to ventilation that removes the moist air from homes, landlords can provide insulation and double-glazed windows to reduce condensation. This can be particularly challenging at the edge of roofs, with one landlord recommending an approach that adds insulation under tiles rather than into the loft.

Insufficient Heating

Inadequate heating can contribute to damp and mould problems. Cold rooms are more prone to condensation, and the lack of warmth can hinder the drying of damp areas. The cold further exacerbates the health risks facing tenants.

Using existing property data, landlords can identify those homes that are hardest to heat and helping landlords identify potential improvements to reduce heating costs.  Parity Projects recommends this is assessed using heat demand rather than SAP ratings alone. Smart controls and monitoring services can be used to monitor for the risk of underheating, and to understand if further support is required but landlords currently have a limited number of units available to monitor homes. Parity Projects Health Risk Predictor service identifies homes most in need of monitoring, and the risk assessment can also learn from those homes where issues have already been found through monitoring.

Lifestyle Factors

There is a risk that, with the guidance, tenant behaviour is not discussed, and therefore their needs are not identified and met. Activities like drying laundry indoors, not using extractor fans, and overcrowding can exacerbate damp problems. But they also indicate lack of facilities, ventilation and/or space.

Some education on ventilation may be appropriate, but only as part of a package of interventions and it takes time. Tenants need alternatives that work such as drying spaces, secure ventilation and sufficient living space.

Identifying risk

Landlords identify risks through multiple channels: primarily complaints but also gas safety checks, resident meetings, neighbourhood officers, voids and stock condition surveys. Parity Projects Portfolio service can help by identifying homes that may be harder to heat, are bedsits, or have characteristics that create risk such as single glazing or flat roofs. But what about less obvious patterns across the stock?

Parity Projects Health Risk Predictor service applies machine learning to landlords’ data to predict health hazards across their stock. This service identifies risks for each address by layering stock condition data from monitoring and surveys with Portfolio or Pathways data, and applying machine learning and statistical predictions over the combined datasets.

The service predicts – at address level – the likelihood of damp or mould; excess cold; fires; electrical hazards; risks from carbon monoxide or poisoning from other fuel combustion or risks from falls inside or around the property. If you are a landlord or local authority who would find this helpful to make sense of data across your stock, contact us to find out more.