The Housing Ombudsman maintains a substantial learning resource on damp and mould, built from casework where landlords got it wrong. It is written for social landlords, but strip out the complaint-handling procedure and what remains is a fairly precise account of how damp problems are mishandled — by anyone.

Three failures that recur

Blaming the occupant. The classic response to reported mould is "lifestyle" — too much drying indoors, not enough ventilating. Occupant behaviour genuinely affects moisture load, but a home should be capable of handling normal household activity. If it cannot, the building is the problem. The Ombudsman has been consistent on this.

Treating the symptom. Wiping and repainting with anti-mould paint addresses the visible growth and nothing else. The mould returns because the cold surface and the moisture are both still there.

Not investigating properly. Assuming rising damp and installing a chemical damp-proof course, when the actual cause was a blocked gutter, a bridged cavity, or condensation on an uninsulated reveal. Different causes, different fixes, and the wrong one is expensive.

The homeowner version

If you own your home, nobody is going to hold you to a 10-working-day investigation standard. But the diagnostic order is the same:

  1. Where is the water coming from? External defect, plumbing leak, or condensation. Look at where the mould is — condensation appears on the coldest surfaces and in unventilated corners; penetrating damp appears where the water gets in.
  2. Why is that surface cold? Missing insulation, a thermal bridge at a reveal or wall junction, an unheated room.
  3. Where is the moisture supposed to go? Check the extract fans actually run, actually vent to outside, and are used.
  4. Then fix in that order. Not paint first.

Why this is converging with energy policy

Awaab's Law Phase 2 brings excess cold into the enforceable hazard regime from 30 November 2026, and the private rented sector faces a C-equivalent standard by 2030. Cold, damp and energy efficiency are increasingly the same conversation, and are increasingly measured by the same visit.

Our retrofit assessment covers ventilation and condition alongside the energy model. Get in touch if you want a look at a specific problem.