PBC Today asks whether Awaab's Law is making a difference on damp and mould. The legal answer is that it has put hard timescales on social landlords: investigate a potential significant hazard within 10 working days, provide a written summary within 3 working days of concluding, and carry out safety work within 5 working days where a significant hazard is found.

The building answer is more stubborn, and it applies to owner-occupiers just as much as to tenants.

Most "damp" is condensation

Genuine rising damp exists and is rarer than the damp-proofing industry suggests. Penetrating damp from a failed gutter or a cracked render is common and fixable. But the majority of what we see reported as damp in London flats and terraces is condensation — water vapour produced indoors meeting a cold surface.

A household of four generates a substantial volume of moisture daily through cooking, washing, drying clothes and simply breathing. That moisture has to leave the building. In an old, leaky house it left through gaps. In an improved house, it does not.

The improvement trap

Here is the sequence we see repeatedly:

  1. New double glazing goes in, sealing the largest source of accidental ventilation.
  2. Draughts are proofed, chimneys blocked, letterboxes brushed.
  3. Trickle vents are closed because they feel draughty in January.
  4. Extract fans are either absent, not ducted to outside, or too weak to meet required flow rates.
  5. Mould appears in the coldest corners — window reveals, external wall corners, behind furniture.

Every individual step was an improvement. Together, without a ventilation strategy, they created the problem.

What to do instead

Insulation raises the temperature of internal surfaces, which genuinely reduces condensation risk — so insulating is part of the solution, not the cause. The cause is sealing without ventilating. Any competent retrofit specification pairs the two, which is why PAS 2035 makes ventilation assessment part of the process rather than an afterthought.

Practically: extract fans in kitchen and bathroom that actually work and actually vent outside, background ventilation left open, and heating that maintains a reasonably even temperature rather than short violent bursts.

Our retrofit assessment looks at condition, occupancy and ventilation alongside the energy modelling. We do not fit measures, so the recommendations are not a sales document.