How much does condensation control cost?
The figures that matter, what moves them, and why a survey first often saves money overall.
Quick answer
A positive input ventilation (PIV) unit costs £400–£800 installed and is the most cost-effective whole-home fix for most houses. Whole-house MVHR costs £3,000–£8,000 and suits new build or major refurbishment. An independent condensation or damp survey costs £200–£400 and is worth it where the cause is unclear.
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What the main items cost
Positive input ventilation (PIV) unit, installed
£400–£800What moves the price: Loft access and layout, whether an existing loft hatch run can be reused, heated vs unheated variant, and whether any electrical work is needed.
MVHR (mechanical ventilation with heat recovery), whole house, installed
£3,000–£8,000What moves the price: Property size, number of wet rooms and habitable rooms, ductwork routing difficulty, and whether it is fitted during a refurbishment (much cheaper) or retrofitted into a finished home.
Independent condensation or damp survey
£200–£400What moves the price: Property size and location. A written report — not a free contractor sales visit — is what makes it worth paying for.
Ranges are indicative UK figures for a typical residential property. Always get written quotes.
Priced per property — get a quote
These vary too much with the property to give a meaningful single range — they depend on room count, access, the existing system and the fabric:
- Continuous extract fans (dMEV) — per fan or per property
- Intermittent extract fan, supplied and fitted
- Trickle vents retrofitted to existing windows
- Loft, cavity or solid-wall insulation
- Heating system upgrades and controls
- Dehumidifier — unit cost plus running cost
When the survey pays for itself
A £200–£400 survey is cheap insurance against a four-figure mistake. Pay for one when: the cause is genuinely unclear; a previous “fix” didn’t work; a contractor has diagnosed rising damp and wants to inject a DPC; or you are a landlord who needs written evidence of investigation. Skip it only when the cause is obvious and the fix is low-cost and low-risk (e.g. replacing a dead bathroom fan).
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Condensation control cost — FAQs
- How much does a PIV unit cost to install?
- A PIV unit including installation typically costs £400–£800. It is one of the most cost-effective interventions for condensation mould in a property with loft access. Price varies with loft layout, the PIV variant (some include a heater), and any electrical work required.
- How much does MVHR cost?
- A whole-house MVHR system typically costs £3,000–£8,000 installed. It is significantly cheaper when fitted during a refurbishment, when ductwork can be run before rooms are finished, than when retrofitted into an occupied home. It is best suited to new build or substantial renovation.
- Is a condensation survey worth paying for?
- Usually yes, if there is any doubt about the cause or the property has had failed fixes before. An independent survey (£200–£400) with a written report tells you whether you are dealing with condensation, rising damp, penetrating damp or something else — and stops you spending four figures on the wrong solution. Be wary of free surveys from contractors who sell the treatment.
- What is the cheapest way to reduce condensation?
- Making sure existing extract fans work and are ducted outside, opening or fitting trickle vents, and keeping heating steady rather than intermittent cost little or nothing. If that isn't enough, a PIV unit is the lowest-cost effective whole-home step in a house with a loft.
- Will insurance or a grant cover condensation work?
- Building insurance generally excludes condensation and gradual damp. Some energy-efficiency schemes and local authority programmes can contribute to insulation and heating improvements for eligible households, which also reduce condensation. Availability changes — check current schemes on GOV.UK and with your local council.