Damp and Mould in London Lets: How to Force a Repair

What is in force, and what is not

If a letting agent tells you Awaab's Law now covers your flat, they are wrong, and it matters. Awaab's Law has applied to social landlords in England since 27 October 2025, under the Hazards in Social Housing (Prescribed Requirements) (England) Regulations 2025. Private landlords are not yet inside it. The Renters' Rights Act 2025 contains the power (section 60) to extend the same duty to assured tenancies, but the regulations that would set the timescales and the start date are still waiting on a government consultation. Guidance published this summer by the Federation of Damp, checked in June 2026, says no date has been confirmed.

The useful part: you do not need it. The tools that force a repair on a private landlord this month are older and blunter, and the Act has just made two of them considerably more dangerous to ignore.

The 2035 date on that last row is not a typo. The government's policy statement of 28 January 2026 confirmed a single five-criterion standard across social and private renting, including a new standalone criterion that a home must be free of damp and mould before it becomes a health hazard, and gave the private sector until 2035 to comply. Anyone selling you the Decent Homes Standard as a live right today is selling you 2035.

The scale of the problem, in official numbers

The English Housing Survey headline report for 2024-25, published in January 2026, found that 10% of private rented homes had a problem with damp, against 7% of social rented and 4% of owner-occupied homes. Private rented homes were also the most likely to have more than one type of damp at once (2.9%). Severe condensation was the most common form nationally at 3% of all homes, ahead of penetrating damp at 2% and rising damp at 1.5%.

That distinction is the whole argument you will have with your landlord. Condensation is the type they blame on you.

On the Decent Homes Standard, the same survey puts 22% of private rented homes below the current version. The government's impact assessment for the reformed standard estimates that around 48% of private rented homes would fail the updated definition, most of them on disrepair. Read that as: roughly half of London's rented stock has nine years to sort itself out.

The escalation chain that works today

Step one: create the paper trail, this week

The 2018 Act is a contract claim. It works by amending sections 8 and 10 of the Landlord and Tenant Act 1985 so that your landlord must keep the property fit for human habitation at the start of the tenancy and throughout it. Barristers on both sides agree on the test: a small patch of mould is not enough. You must show the defect is serious enough that the home is not reasonably suitable for occupation, which in practice means a real risk to health. The Act also gives your landlord a defence where the problem is caused by your own default.

So build the record that kills the lifestyle argument before it starts.

• Report in writing, by email, every time. Not WhatsApp voice notes to the agent's personal mobile.
• Photograph each affected wall with something in frame for scale, and repeat monthly from the same spot. Growth over time is the evidence.
• Log a humidity reading in the affected room, and one in an unaffected room, at the same time of day.
• Note what you do to ventilate: windows open, extractor fan on, no drying laundry indoors. If the fan does not work, or the bathroom has no fan, say so in the email. That is a defect, not a habit.
• Ask your GP for a note if anyone in the household has a respiratory complaint. Under Awaab's Law in social housing, medical evidence accelerates the clock, and private landlords' insurers are already treating it as a red flag.
• Keep every reply. Silence is also evidence.

One line to put in that first email: "Please confirm in writing whether you consider the cause to be condensation, penetrating damp or rising damp, and on what basis." An agent who cannot answer has not investigated, and that is the point you will make later.

Step two: your borough's environmental health team

Councils enforce the Housing Health and Safety Rating System. A damp and mould hazard scored as Category 1 obliges the council to act, usually by improvement notice, and Category 2 hazards can be enforced at the council's discretion. You do not need your landlord's permission to make the request, and the council inspects the flat rather than interviewing you about your drying rack.

Two things to know before you ring. First, check whether your flat needs a licence. Kamma's 2026 analysis of licensing enforcement found 28 of the 32 London boroughs operating licensing restrictions, with fines in London reaching £25m. An unlicensed flat gives you a second, easier route. Second, ask the officer to send you a copy of the notice or inspection outcome. That document is the foundation of everything below it.

Step three: the money

The Renters' Rights Act sharpened both financial routes as of 1 May 2026. Maximum civil penalties for landlord offences rose to £40,000 per offence, replacing the previous £30,000 cap. Rent repayment orders doubled: Shelter's legal guidance confirms that for offences committed on or after 1 May 2026, a tenant or the council can apply to the First-tier Tribunal for up to two years of rent, within two years of the offence, and the landlord does not need to have been convicted first, though the Tribunal must be satisfied beyond reasonable doubt.

Failing to comply with an improvement notice is an offence. That is the link most tenants miss between a council inspection and a five-figure repayment.

Separately, a disrepair claim under the 2018 Act can ask the court to order the works and award damages, and it follows the Pre-Action Protocol for Housing Conditions Claims. Solicitors will take these on a conditional fee basis. Before you sign with a claims firm that cold-called you, get the council inspection done anyway. It costs nothing and it strengthens the claim.

What the end of Section 21 changes about complaining

The old calculation was rational and grim: complain in month four, get two months' notice in month five. The Deregulation Act 2015 offered some retaliatory-eviction protection after an improvement notice, but only if you had already got that far.

Since 1 May 2026, no new Section 21 notice can be served in England, and section 8 of the Housing Act 1988 is the only statutory route to possession. Generation Rent's summary of the position is blunt: landlords now need a valid reason. Fixed terms have gone, all tenancies are periodic, and tenants can give two months' notice at any point. Rent can be raised only once a year, by the statutory section 13 procedure, with two months' notice, and you can challenge it as above market rent at the Tribunal.

Retaliation has not vanished. It has become identifiable. A landlord who suddenly discovers an intention to sell three weeks after your mould email is relying on a ground with its own notice requirements and restrictions, and a Tribunal that can be shown a dated email chain. Keep the chain tidy for that reason alone.

Two smaller housekeeping items worth chasing this week. Every landlord had to give tenants the official Renters' Rights Act Information Sheet 2026 by 31 May 2026, with a penalty of up to £7,000 per tenancy for missing it. If you never received it, ask. Landlords also cannot demand more than one month's rent in advance, or accept above the advertised rent, which is worth knowing if you are searching now. Our piece on how open banking is reshaping rent payments covers the payment side of that.

Which London councils actually act

Published enforcement records are a better guide than a council's damp webpage. Kamma's ranking of licensing enforcement singles out Camden and Islington for running a pipeline that converts council prosecutions into rent repayment order applications, and Tower Hamlets for providing free legal representation to tenants. Newham has the longest-running borough-wide licensing scheme in the country and a correspondingly large prosecution list.

If you are renting in a borough with a thin enforcement record, the 2018 Act claim carries the weight instead, because it does not depend on the council doing anything.

Viewing checks, and why August viewings flatter a flat

Winter is when a damp flat confesses. In August, a flat with a serious condensation problem can look and smell fine after a week of open windows. These are the tells that survive summer, keyed to the stock you will actually be shown.

• Victorian and Edwardian conversions (Walthamstow, Tooting, Hackney): solid brick walls, no cavity. Press the wall behind the bed head and in the corner of the coldest external wall. Look for fresh paint on one wall only, and for a skirting board that has been replaced while its neighbours have not.
• Lower ground floor and garden flats (Camden, Islington, Kennington, parts of Lewisham): check where the external pavement sits relative to the internal floor. If the ground outside is higher, ask what damp-proofing was done and when. Tide marks under a radiator are not from a spill.
• 1930s mansion blocks (Maida Vale, Streatham, Golders Green): single-glazed steel casement windows are the giveaway. Look for black mould at the window reveals, and ask whether the block has a planned window replacement programme.
• Ex-local authority blocks (Southwark, Tower Hamlets, Barking): cold bridging at panel joints produces mould in tight straight lines rather than patches.
• Office-to-residential conversions (Croydon, Wembley): find the extractor fan and switch it on. Many of these units rely entirely on mechanical ventilation, and a dead fan is a damp flat within one winter.

Ask the agent, by email so you keep the reply: has this property been treated for damp or mould in the last two years, and can you send the works record? Also ask for the EPC. A band E or F flat in solid-walled stock will be cold, and cold walls are where condensation lands. The energy retrofit rules matter here, because privately rented homes must reach EPC C by 1 October 2030, and a landlord facing that bill has a reason to talk to you now.

An agent who answers those two questions in writing is telling you something. So is one who does not.