In social housing, few topics evoke as much concern and confusion as mould. From headlines warning of toxic spores to social media posts blaming ‘lazy’ tenants for its presence, the debate is often polarised. But scratch beneath the surface and it’s clear that we need a more nuanced, diagnostic approach, combining people, process and technology, not just annual mould washes.
The focus must shift from identifying and treating mould to understanding why it’s forming at all, and whether it’s even the most important factor affecting health.
“Is mould dangerous?” – The wrong question
Much of the conversation around mould is unhelpfully black-and-white. Public concern is often based on the idea that all mould exposure is acutely harmful. But a deep dive into the scientific evidence, including peer-reviewed human studies, reveals a more complex picture.
While mould is linked to respiratory and skins conditions, the direct link between mould and any disease or chronic neurological illness remains suggestive, not conclusive. Many studies point to inflammation and immune response as key mechanisms, but often in conjunction with other environmental stressors, such as poor air quality, under-heating or dampness.
A study of 49 residents living with mould concluded that, “In all cases, sensitisation to moulds was accompanied by allergy to other common allergens. No isolated hypersensitivity to moulds was found. […] Although the frequency of self-reported symptoms was high, the prevalence of atopy and allergic diseases seems to be similar to that found in the general population.”
Perhaps we’ve been asking the wrong question; instead of asking, “Is mould is toxic?”, we should be asking, “What are the conditions in this home, and how do they affect health?”.
A pragmatic & proportionate approach
That’s not to say mould should ever be ignored. Mould indicates excess moisture and it can be unpleasant, embarrassing and, in some cases, harmful. But like dust, pollen or even carbon monoxide, its risk depends on the concentration, duration of exposure and vulnerability of the occupant. A UCL study on normal background mould levels provides important context: low-level spores are always present.
This is where context and communication matter. Scaremongering headlines or dismissive contractor comments both miss the mark. A more proportionate approach means:
- Treating small patches of surface mould promptly and safely, whether that’s a housing provider or tenant responsibility.
- Providing guidance and tools to tenants for prevention.
- Ensuring building defects, leaks and ventilation failures are diagnosed and resolved.
- Investing in skilled surveyors, multi-skilled teams, increasing building pathology practice, environmental monitors and empathetic tenant engagement.
- Using AI-powered diagnostic and communication tools.
Just as with health, early intervention works best. By combining tools for accurate diagnosis with preventative maintenance, we can move from firefighting mould problems to foresight, stopping small problems before they escalate and harm both structure and wellbeing.
The advice for treatment:
- Organisations such as WHO and CDC stress that while mould should be prevented and removed, small-scale cleaning is often appropriate if done carefully.
- The UK government’s 2024 guide on damp and mould suggests tenants may reasonably clean or treat small areas, avoiding bleach.
From mould washes to modern maintenance
For too long, the go-to response has been the annual ‘mould wash’. It’s merely a ‘sticking plaster’ over potential problems and, in many cases, it also reinforces the behaviours that cause the mould in the first place.
In a project analysing five years of repairs data and tenant feedback, I found that tenants who treated mould themselves and were given clear advice were over twice as likely to report ‘no mould returning’ compared with tenants who received advice plus a mould treatment by their housing provider.
Those who succeeded said the advice was clear and simple, and that the changes they implemented improved their home environment. Those whose mould returned often assumed that because the housing provider had treated it, there must have been a structural defect and so felt that the advice didn’t apply to them.
The Ombudsman’s ‘It’s Not Lifestyle’ report and Awaab’s Law don’t exclude tenant behaviours from consideration, but they do shift the default. Housing providers must prove the absence of defects, consider improvements and offer meaningful signposting and support.
The bigger picture – It’s not always mould
Research consistently shows that homes with visible mould often have other overlapping risk factors, such as underheating and high levels of carbon dioxide. In some cases, homes with no visible mould may still be harming occupants through stale air, pollutants or excessive dryness. That’s why we must consider:
- Ventilation effectiveness, not just whether fans are installed;
- Temperature variation across the home, not just during inspections;
- Fuel poverty, tenant behaviour and fear of energy bills;
- Dust, VOCs, cooking pollutants and overcrowding;
- Mental health and behavioural habits, including hoarding or isolation.
Taking a whole-system view allows us to see how building condition, indoor environment and occupant health interact, and how good maintenance, data and advice can improve all three.
Communication is a diagnostic tool
Finally, none of this works without trust. Tenants often don’t report mould early due to fear of blame, previous bad experiences or not knowing what ‘normal’ is. At the same time, surveyors and operatives may fall back on routine scripts or misattribute causes to ‘lifestyle’.
We need better conversations. That means:
- Using SET communication models (support, empathy & truth);
- Avoiding loaded terms such as ‘tenant fault’;
- Being honest about uncertainty and how we’re investigating it;
- Explaining next steps and timeframes clearly.
Communication isn’t just customer service, it’s part of the diagnostic process.
Diagnosis over decibels
As public awareness grows, the social housing sector is rightly under scrutiny. But our response must be calm, evidence-based and focused on systems, not symptoms.
Mould is real. Its health effects are plausible but they’re also often entangled with other avoidable environmental and social factors. Treating the wall is easy; understanding the home and supporting its inhabitants takes more skill.
If we embrace technology, train our people well, engage tenants meaningfully and commit to accurate diagnoses over cosmetic fixes, we won’t just reduce damp and mould, we’ll improve homes and health for the long term.
Rosie Wills is a chartered construction manager (MCIOB) and building surveyor (AssocRICS) at Nova Surveyors.
