Damp and mould in rental properties used to be treated, too often, as a relatively ordinary maintenance issue. A patch on a wall. A note on a check-out. A disagreement about windows, heating or condensation.
That world is disappearing.
Under the changing rental landscape, damp, mould and condensation are becoming something much bigger. They are now a health issue, a compliance issue, a tenant communication issue, a property management issue and, increasingly, an evidence issue.
The Renters’ Rights Act has already brought significant change to private renting in England. From 1 May 2026, Section 21 “no fault” evictions were abolished, most new and existing private rented tenancies became assured periodic tenancies, and landlords must now rely on specific legally valid possession grounds if they need to end a tenancy. Letting agents acting on behalf of landlords also need to follow the new rules. (Housing Hub)
But the Act is not only about evictions. It sits within a much wider direction of travel: higher standards, clearer responsibilities, more scrutiny and better evidence.
The government’s implementation roadmap says the second phase of reform, from late 2026, will introduce a Private Rented Sector database and a Landlord Ombudsman. It also says phase three will focus on raising standards through the extension of Awaab’s Law and a modernised Decent Homes Standard to the private rented sector, although the timescales for those changes remain subject to consultation. (GOV.UK)
For landlords, agents and inventory clerks, the message is clear: damp and mould can no longer be treated as a vague note in the margin.
It needs to be understood, recorded, reported and followed up properly.
The important shift: from “who caused it?” to “what evidence do we have?”
One of the least helpful conversations in the rental sector is the immediate argument about blame.
Landlord says: “The tenant is not ventilating the property.”
Tenant says: “The property is defective.”
Agent says: “We need more information.”
Clerk says: “I can only record what I can see.”
And often, everyone is partly right.
This is why damp and mould is such a difficult subject. It is rarely one thing. It can involve condensation, inadequate ventilation, insufficient heating, poor insulation, penetrating damp, rising damp, leaks, blocked gutters, failed extractor fans, overcrowding, lifestyle factors, design defects or a combination of several issues.
The more useful question is not always “who caused it?”
The better first question is:
What do we know, when did we know it, and how well was it recorded?
That is where the sector has to improve.
What landlords are expected to do
Government guidance on damp and mould is clear that damp and mould can pose serious health risks. It says landlords should respond quickly, document the location of mould before removal, tackle the underlying causes, and understand that simply removing surface mould will not prevent it from returning if the cause remains. (GOV.UK)
The same guidance encourages landlords to have clear processes to document, manage and act on damp and mould reports, to understand the condition of their homes, and to make interventions around ventilation, energy efficiency and building deficiencies before damp and mould occurs. (GOV.UK)
That point matters.
A landlord who treats mould as a cleaning problem may miss the bigger issue. A landlord who treats every report as “tenant lifestyle” may miss a repair obligation. A landlord who treats every report as a building defect may miss practical steps around ventilation, heating and moisture management.
The professional response is not assumption.
The professional response is investigation, documentation and action.
The role of ventilation: the boring detail that may become the big issue
Ventilation is not glamorous. It is not usually the part of the property people notice first. Nobody rents a flat because the extractor fan has a good backstory.
But ventilation is one of those boring details that quietly determines whether a property works.
The latest HHSRS landlord and agent guide includes ventilation and moisture control within its baseline indicators. It refers to issues such as moisture-laden air being exhausted externally from bathrooms, kitchens, clothes dryers and basements, habitable rooms having openable windows or doors, and ventilation being maintained in good repair and working order. It also includes a moisture and contaminant control indicator that no room should have observable damp or mould growth or deterioration of internal finishes exceeding 5% of the wall or ceiling surface. (GOV.UK)
That does not mean inventory clerks are expected to become surveyors. They are not.
But it does mean property professionals should start paying more attention to the visible signals:
Are extractor fans present?
Are they working at the time of visit?
Are trickle vents present, open, closed, painted over or missing?
Are windows openable?
Is there condensation on glazing?
Are there signs of black spot mould around window reveals, ceilings, external walls or behind furniture?
Are there signs of staining, blistering paint, tide marks, peeling wallpaper or musty odours?
Are there obvious leaks, blocked vents or damaged seals?
Small observations can become very important later.
What agents should be thinking about
Letting agents are often the bridge between tenant, landlord, contractor and clerk. That makes their process crucial.
A good damp and mould process should make it easy to answer:
When was the issue first reported?
Who reported it?
Was it treated as urgent?
Were photographs requested?
Was an inspection arranged?
Was the landlord informed?
Was a contractor instructed?
Was the tenant updated?
Was the underlying cause investigated?
Was there a follow-up after works were completed?
Has the issue appeared before?
The government’s damp and mould guidance recommends that landlords maintain up-to-date records on housing conditions and reports of damp and mould, including informal reports and any investigation or remediation action. It also recommends follow-up systems to check treatment has been effective and that damp and mould has not reappeared. (GOV.UK)
This is where many disputes are won or lost: not at the point of argument, but months earlier, when the first report was or was not recorded properly.
What inventory clerks should record
Inventory clerks are not there to diagnose the root cause of damp and mould unless they are specifically qualified to do so.
That is an important distinction.
A clerk should usually avoid definitive language such as:
“Tenant-caused mould.”
“Rising damp.”
“Penetrating damp.”
“Structural damp.”
“Poor tenant ventilation.”
Those may be possibilities, but unless the evidence is clear and the clerk is qualified to make that assessment, they are risky conclusions.
Better wording is factual, neutral and visible-evidence led:
“Black spot mould-like marks noted to ceiling above window.”
“Condensation present to inside of bedroom window at time of inspection.”
“Extractor fan present in bathroom; not tested / appears operational / no visible operation observed.”
“Brown staining noted to wall below window sill.”
“Peeling paint and bubbling plaster noted to external-facing wall.”
“Musty odour noted on entry to room.”
“Tenant reports issue has been raised with agent; not independently verified at inspection.”
The goal is not to win an argument.
The goal is to create a reliable record.
That distinction is very AIIC. Independent inventory work is most valuable when it is calm, neutral and precise.
Awaab’s Law: why the direction of travel matters
Awaab’s Law currently applies to most social housing tenants, not private rented sector tenants. Under the current social housing guidance, significant damp and mould hazards must be investigated within 10 working days and made safe within 5 working days after the investigation finishes; emergency hazards must be dealt with within 24 hours. (GOV.UK)
However, the Renters’ Rights Act roadmap confirms that Awaab’s Law is expected to be extended to the private rented sector in a later phase, subject to consultation. (GOV.UK)
So even before the private rented sector extension arrives, landlords, agents and clerks should treat this as a warning shot.
The future is likely to be more time-sensitive, more evidence-led and less tolerant of vague handling.
Practical hints for landlords, agents and clerks
Here are some practical steps worth considering now.
1. Take every damp and mould report seriously
Even if the issue appears minor, record it properly. Make a note of the date, location, description, photographs, tenant comments and next action.
2. Avoid jumping straight to blame
Condensation may be linked to ventilation and heating patterns, but it may also be linked to design, insulation, defective extraction or property condition. Start with evidence.
3. Photograph before cleaning or treatment
Government guidance specifically recommends photographing and documenting the location of mould before removal to help identify the source. (GOV.UK)
4. Check ventilation as part of the property picture
Extractor fans, trickle vents, openable windows, blocked vents and moisture-heavy rooms all matter. Ventilation is not a side issue; it is often part of the story.
5. Use neutral reporting language
Inventory and inspection reports should describe what is visible, not overreach into technical diagnosis.
6. Follow up
If remedial work is carried out, the question should not simply be “was the mould removed?” It should be “has the issue returned?” Government guidance recommends inspecting the home at least 6 weeks after remedial work to ensure the issue has been fixed and damp and mould have not reappeared. (GOV.UK)
7. Train the people who see properties most often
Clerks, agents, contractors and property managers are often the first people to spot patterns. If they are not trained to notice and record the right things, the evidence may be lost before the issue becomes serious.
The bigger point: damp and mould is a trust problem
There is a Rory Sutherland-ish way to look at this.
Damp and mould is not only a physical defect. It is a trust accelerant.
A small patch of mould can become a major dispute because it changes how everyone interprets everyone else.
The tenant may think: “They do not care.”
The landlord may think: “They are not using the property properly.”
The agent may think: “We need proof.”
The clerk may think: “This needs to be recorded carefully.”
The problem becomes worse when nobody has a shared factual record.
Good reporting does not magically solve damp and mould. But it does create a common starting point. It gives landlords better information. It gives agents a clearer audit trail. It gives tenants greater confidence that the issue has been seen. It gives contractors better context. And it gives clerks a more valuable role in the professional management of rented homes.
In other words, better evidence is not paperwork.
It is how the rental sector reduces suspicion.
Do you want to get up to date?
The AIIC is currently taking notes of interest for a practical training course on damp, mould and condensation in rental properties, provisionally planned for Wednesday 14 October 2026.
The course will be aimed at inventory clerks, letting agents, landlords and property professionals who want to better understand:
What has changed in the rental sector
What landlords and agents are expected to consider
How damp, mould and condensation should be recorded
What language to use, and what language to avoid
How improved ventilation fits into the wider picture
How to keep reports factual, neutral and useful
Why evidence and follow-up are becoming more important
To register your interest, email:
Subject line suggestion:
Damp and Mould Training Interest
Damp and mould is not going away as an issue. If anything, it is moving closer to the centre of property standards, tenant safety and rental sector professionalism.
The question is not whether landlords, agents and clerks will need to understand it better.
The question is how soon they choose to get up to date.
FAQ section
What should landlords do when damp or mould is reported?
Landlords should take reports seriously, record when and how the issue was reported, inspect or investigate the problem, document the location with photographs, identify and address the underlying cause where possible, communicate clearly with the tenant and follow up after any works are completed. Government guidance says simply removing surface mould will not prevent it from returning if the underlying causes are not tackled. (GOV.UK)
Is Awaab’s Law already in force for private landlords?
Awaab’s Law currently applies to social rented housing. The government’s Renters’ Rights Act roadmap says it is expected to be extended to the private rented sector in a later phase, subject to consultation. (GOV.UK)
Should inventory clerks diagnose the cause of damp and mould?
Generally, no. Unless specifically qualified, inventory clerks should avoid diagnosing causes such as rising damp, penetrating damp or tenant-caused condensation. The safer and more professional approach is to record visible evidence clearly, neutrally and accurately.
What should an inventory report say about mould?
A good report should describe the location, appearance, extent and context of visible mould-like marks. It may also note related observations such as condensation, staining, peeling paint, extractor fans, ventilation, window condition and any tenant comments, while making clear what has and has not been independently verified.
Why is ventilation important in rental properties?
Ventilation helps manage moisture. Poor or ineffective ventilation can contribute to condensation, damp and mould. The HHSRS landlord and agent guide includes ventilation and moisture control within its baseline indicators, including working ventilation and the removal of moisture-laden air from areas such as kitchens and bathrooms. (GOV.UK)
