Winter Damp and Mould Checklist for UK Landlords

Short answer: most damp and mould complaints arrive between November and March, when homes are shut up, heating is rationed and outside surfaces are cold and wet. The landlords who avoid them do four things before the cold sets in: make sure every wet room can get moisture out, make sure the heating and insulation keep surfaces warm, make sure the outside of the building keeps water out, and make it easy for tenants to report problems early. Then they keep a record of all of it.

This checklist is written for England, where the updated Housing Health and Safety Rating System (HHSRS) and, for social landlords, Awaab's Law set the standard. The building checks apply anywhere in the UK.

Why winter matters more than ever

The HHSRS changed in June 2026. Councils in England now work from baseline indicators, including a limit of 5% observable damp or mould on any wall or ceiling surface in a room. Our HHSRS 2026 explainer covers the detail.
Penalties went up. Failing to comply with an improvement notice can now bring a civil penalty of up to £40,000.
Awaab's Law is widening for social landlords. From 30 November 2026 the timeframes extend to further hazards, including excess cold. See Awaab's Law Phase 2.
Private landlords are next in line. The government is consulting on applying Awaab's Law to the private rented sector, with the consultation closing on 18 December 2026. No start date is set, but the direction is clear. Track it on our private rented sector page.

1. Ventilation

Test every extractor fan. Bathrooms should extract at least 15 litres per second on an intermittent fan; kitchens 30 l/s if the extract is over the hob, 60 l/s elsewhere (Approved Document F). If a fan can't hold a sheet of toilet paper to its grille, it probably isn't close.
Check fans run long enough. An overrun timer or humidistat keeps them going after the shower or cooker is off.
Check ducts actually reach outside, especially in lofts, and aren't crushed or disconnected.
Check trickle vents are fitted, not painted shut, and not missing their covers.
Service whole-house systems. PIV, dMEV and MVHR units need filter changes and a check that they're running.
Tumble dryer venting. If a vented dryer is supplied or allowed, make sure there's a proper outside vent.

Our guide to trickle vents and Approved Document F covers the requirements.

2. Heating and insulation

Boiler or heating service done before the first cold snap, with a gas safety certificate in date where relevant.
Every habitable room has a working heat source that the tenant can control, ideally with thermostatic radiator valves.
Loft insulation checked for depth and gaps, especially at the eaves and above bathrooms. Government guidance on damp and mould suggests at least 270mm.
Cold spots noted from previous winters: corners, window reveals, wall-to-ceiling junctions. These are often thermal bridges that need insulating rather than cleaning.
EPC. Private rented homes in England and Wales generally need an EPC rating of E or above to be let. Damp and cold often go together.

3. The building envelope

Gutters and downpipes cleared after leaf fall and checked for leaks at joints.
Roof checked for slipped or missing tiles, failed flashing and blocked valleys.
Pointing and render checked for cracks that let water into walls.
Window and door seals intact; sills shedding water away from the wall.
Ground levels and air bricks. Soil or paving shouldn't be piled above the damp-proof course, and air bricks shouldn't be blocked.
Plumbing. Exposed pipes in lofts and outbuildings lagged against freezing; the tenant knows where the stopcock is.

Damp that appears after rain rather than after cold nights usually comes from outside. If you're unsure, our guide to condensation or rising damp helps, and an independent damp survey settles it.

4. Tenant communication

Tell tenants how to report damp and mould, and make it easy: one email address or a form, with photos encouraged. Ask them to report early.
Explain the ventilation: keep trickle vents open, run fans, leave whole-house systems on.
Give practical tips on drying washing, without blaming. Government guidance says it is unreasonable to blame damp and mould on tenants' "lifestyle choices". Our post on drying clothes indoors without mould is written to be shared.
Ask about vulnerable occupants. Babies, older people and anyone with lung conditions or a weakened immune system are at higher risk, and that should affect how quickly you act.
Arrange access properly. For inspecting the condition of the property, give the tenant at least 24 hours' written notice.

5. Response plan

Decide now what happens when a report comes in, rather than at 6pm on a Friday in January.

Who triages it, and how quickly someone looks at photos.
Who inspects, and within what timeframe. Social landlords must investigate significant hazards within 10 working days and emergencies within 24 hours under Awaab's Law. Private landlords have no fixed timeframe yet, but working to similar standards is sensible.
Which contractors you'll use for mould treatment, ventilation, roofing and plumbing, with contact details agreed in advance. Find verified specialists near you.
What "fixed" means. Cleaning mould is not a repair. Find and deal with the cause, and re-inspect afterwards; government guidance suggests a follow-up at least six weeks after treatment.

6. Records

Keep a simple log for every property:

date each report was received and how
date inspected, by whom, and what they found (with photos)
cause identified and work done
dates the tenant was updated
follow-up inspection result

If a tenant ever complains to the council or a tribunal, this log is the difference between "we acted reasonably" and "we can't prove it". Letting agents can use our guide to setting a damp and mould policy.

FAQs

When should landlords do a winter damp check?

Ideally in October or early November, before heating demand peaks and before leaves block gutters. Then respond quickly to any reports through the winter.

Is a landlord responsible for condensation mould?

Often, yes, where it's caused by inadequate ventilation, heating or insulation. Our guide who is responsible for damp and mould? explains how responsibility is decided.

Do private landlords have to follow Awaab's Law this winter?

No. It currently applies to social landlords only. Private landlords are subject to the HHSRS and the duty to keep homes fit for human habitation.

What's the quickest win on this list?

Testing and upgrading extractor fans. It's cheap, quick, and fixes a large share of bathroom and kitchen mould.

Winter damp and mould checklist for landlords