Damp and Mould Monitoring for UK Social Housing: Meeting Awaab’s Law with Continuous Sensing

Last updated: 2 July 2026

TL;DR: Damp and mould monitoring uses IoT sensors to track temperature, relative humidity and CO2 in social homes so landlords catch condensation risk before it becomes a health hazard. Under Awaab’s Law, in force for the social rented sector from 27 October 2025, landlords must investigate damp and mould hazards within 10 working days. Continuous sensor data gives early warning and a defensible evidence trail of proactive compliance.

The death of two-year-old Awaab Ishak changed how England regulates damp in rented homes. This guide explains the law, the numbers behind the problem, and the concrete monitoring stack a landlord can deploy now. It is written for housing providers who need to act, not just react.

What is Awaab’s Law and when did it come into force?

Awaab’s Law is a set of legal repair timescales for the social rented sector, introduced through the Social Housing (Regulation) Act 2023. It came into force from 27 October 2025. From that date, social landlords must address emergency hazards and all damp and mould hazards that present a significant risk of harm to tenants within fixed, legally binding timeframes (GOV.UK).

The law is named after Awaab Ishak, who died in Rochdale. The Prevention of Future Deaths report, issued by HM Senior Coroner Joanne Kearsley on 16 November 2022, found that his death followed prolonged exposure to mould in his home (Courts and Tribunals Judiciary). The case exposed how normal condensation, left unaddressed, can become fatal.

The regulations are being phased. From October 2025 they cover emergency hazards and damp and mould. In 2026 they extend to further hazards such as excess cold and heat, falls, structural collapse, fire and electrical safety. In 2027 they extend to all remaining Housing Health and Safety Rating System hazards apart from overcrowding (GOV.UK). Damp and mould sit in the very first wave, which is why this hazard is the immediate compliance priority.

What are the exact Awaab’s Law timescales for damp and mould?

For a hazard presenting a significant risk of harm, the guidance for social landlords sets clear clocks. Landlords must investigate the hazard within 10 working days of becoming aware of it. They must produce a written summary of findings and issue it to the tenant within 3 working days of the investigation concluding. If the investigation identifies a significant hazard, relevant safety work must begin within 5 working days (GOV.UK).

Emergency hazards run to a far tighter clock. Landlords must investigate and make the home safe within 24 hours of becoming aware of the emergency (GOV.UK). These are not aspirations. Missing them is a breach a tenant can enforce.

How big is the damp and mould problem in social housing?

Damp is common and getting worse. The English Housing Survey 2024 to 2025 found that 1.4 million dwellings, or 5% of all stock, had a damp problem in 2024, with statistically significant increases since 2022 in the owner occupied and social rented sectors (GOV.UK). Damp affected 7% of social rented homes.

Within social housing the picture varies by landlord type. Local authority dwellings were more likely to have a damp problem, at 8%, than housing association dwellings, at 6% (English Housing Survey, GOV.UK). The most common form of damp was severe condensation, at 3%, more prevalent than penetrating damp at 2% or rising damp at 1%.

The Regulator of Social Housing ran its own survey after the coroner’s report, with a 99% response rate from larger landlords. Its best estimate was that less than 0.2% of social homes have the most serious damp and mould problems, 1 to 2% have serious problems, and a further 3 to 4% have notable damp and mould (GOV.UK). The regulator noted that weaker landlords relied on reactive approaches rather than proactively looking for evidence. That distinction, reactive versus proactive, is exactly what sensing changes.

Why does continuous damp and mould monitoring catch risk early?

Continuous damp and mould monitoring works because mould is a lagging indicator. By the time a black patch appears on a wall, the conditions that grew it have persisted for weeks. Sensors measure those conditions directly, in real time, so a landlord sees the risk building rather than the damage after the fact.

The science is settled on the threshold. Consensus among microbiologists puts the critical relative humidity for adverse biological activity on building envelope surfaces at 70%. Where relative humidity above 70% occurs at a surface, mould growth, dust mite growth, decay and corrosion can occur (Building Science Corporation). Sustained high humidity is the fuel; a cold surface is the trigger.

This is where dew point matters more than air humidity alone. When a wall surface cools to or below the dew point of the surrounding air, that air reaches saturation and liquid water forms on the surface. A room can read a comfortable relative humidity while a cold corner behind a wardrobe or under a window sits soaking wet. Measuring temperature and humidity together lets you calculate dew point and flag the exact cold spots at risk, long before mould is visible.

CO2 adds the third dimension: ventilation. Rising CO2 in an occupied room signals that stale, moisture-laden air is not being exchanged. When CO2 climbs and humidity climbs with it, you are watching condensation risk accumulate in near real time. Together, temperature, relative humidity and CO2 describe both the moisture load and whether the home can clear it.

What monitoring stack should a social landlord deploy?

A landlord can deploy a practical damp and mould monitoring stack today using LoRaWAN, a low-power wireless standard built for exactly this: battery devices that report for years and penetrate concrete and brick across a block. The stack has five layers, and each maps to a proven product class.

Sense. Put an indoor air quality sensor in each at-risk room. A device such as the Milesight AM103 measures CO2 from 400 to 5000 ppm, temperature and relative humidity across 0 to 100% RH, on replaceable batteries rated for around 4.5 years in typical settings (Milesight). Multi-parameter units like the AM319 add particulate and VOC channels where a fuller picture is needed. One sensor per property is enough to establish a baseline; two or three cover the rooms most prone to condensation.

Connect. A single LoRaWAN gateway on a block or estate collects readings from hundreds of sensors without tenant WiFi or SIM cards. This keeps per-property cost low and removes any reliance on a resident’s broadband, which matters for fair, consistent coverage.

Secure. Data from homes is sensitive. Encrypted transport and network segmentation keep readings private and the estate network hardened, an increasingly explicit expectation as housing data platforms grow.

Control. Rules turn readings into action. When humidity holds above 70% for a set window, or a surface approaches dew point, the platform raises a case automatically and routes it to the repairs team, starting the Awaab’s Law clock with a documented trigger.

Manage. A dashboard shows the whole portfolio at a glance, ranks homes by risk, and stores the full history. That history is the compliance evidence.

Which sensors and gateways fit UK social housing?

Indoor air quality sensors that combine CO2, temperature and humidity are the core device, because they measure moisture load and ventilation in one unit. LoRaWAN suits multi-dwelling buildings because one gateway serves a whole block and battery life runs to years, so there is no annual truck roll to swap cells. Explore the hardware options on the Indiott shop, or read our Milesight LoRaWAN gateway buyer’s guide for gateway selection.

How does sensor data prove proactive compliance?

Sensor data proves compliance by creating a continuous, timestamped record of conditions in every monitored home, plus an auditable log of when a risk was detected and when the landlord acted. That record is the difference between saying you take damp seriously and showing it.

The government’s guidance is unambiguous about responsibility. It states that it is “totally unreasonable to blame damp and mould in the home on lifestyle choices” and that the fundamental cause “will be due to building deficiencies, inadequate ventilation, inadequate heating and/or poor energy efficiency, not tenants’ normal domestic activities” (GOV.UK). Continuous data helps landlords honour that. Instead of arguing about tenant behaviour, the readings show whether a home can physically stay dry, and where the fabric is failing.

The Housing Ombudsman reached the same conclusion earlier. Its October 2021 spotlight report, titled “Spotlight on: damp and mould, it’s not lifestyle”, urged a zero tolerance approach and made 26 recommendations for landlords (Housing Ombudsman). Sensing operationalises zero tolerance: you are not waiting for a complaint, you are watching the conditions.

For the most vulnerable residents this matters most. The government notes that children and young people, older people, and those with conditions such as asthma, COPD and other lung diseases are at greatest risk from damp and mould (GOV.UK). Early warning protects exactly these households first, and the data shows a regulator that intervention was proactive, not prompted by harm.

Frequently asked questions

When did Awaab’s Law come into force?

Awaab’s Law came into force for the social rented sector from 27 October 2025, introduced under the Social Housing (Regulation) Act 2023. The first phase covers emergency hazards and all damp and mould hazards that present a significant risk of harm, with further hazards phased in during 2026 and 2027 (GOV.UK).

How long do landlords have to investigate damp and mould under Awaab’s Law?

Landlords must investigate a significant damp and mould hazard within 10 working days, issue a written summary of findings to the tenant within 3 working days of concluding the investigation, and begin relevant safety work within 5 working days where a significant hazard is found. Emergencies must be made safe within 24 hours (GOV.UK).

What humidity level causes mould in a home?

Mould risk rises sharply once relative humidity at a surface exceeds 70%, the critical threshold for biological growth agreed among microbiologists (Building Science Corporation). Because cold surfaces raise local humidity, condensation and mould can appear even when the room’s air reads a comfortable level, which is why dew point and surface conditions matter.

Can IoT sensors really prevent damp and mould?

Sensors do not dry a home on their own, but they detect the conditions that cause damp and mould weeks before visible growth, allowing ventilation, heating or fabric repairs to be actioned early. The value is early warning and evidence, turning a reactive repairs service into a proactive, data-led one.

Do the sensors need tenant WiFi?

No. LoRaWAN sensors connect to a single gateway serving a block or estate, so they do not depend on a resident’s broadband or a SIM card. Batteries last several years, which keeps installation and running costs low across large portfolios.

Conclusion

Awaab’s Law has made damp and mould the first hazard social landlords must chase to a legal clock. Continuous sensing of temperature, humidity and CO2 is the most direct way to catch condensation risk before it harms a resident, and to prove that the response was proactive. Start with a baseline sensor in the homes most at risk, connect them over LoRaWAN, and let the dashboard do the watching. See how the layers fit together on our smart heating and HVAC solution, or explore the wider smart buildings platform to plan a portfolio rollout.