What a properly designed MVHR install actually costs in 2026.
Primary question · What should I budget for MVHR, and what drives the variance between a £6,000 quote and a £14,000 one?
The unit itself is a small fraction of the bill. The honest cost driver is the ducting strategy, the airtightness work that may need to happen first, and a competent commissioning engineer at the end. A first-fit during new-build construction is the cheapest moment, and a deep retrofit through finished plasterboard is the most expensive.
Anyone budgeting a real installed cost rather than a manufacturer-list ballpark.
New build first-fix: £4,500 to £8,000. Deep retrofit in a 3-bed: £7,500 to £14,000. Premium 4-bed install: £12,000 to £22,000.
- Captures the ducting and commissioning that decide whether the system works
- Honest about the airtightness work that often belongs in the budget
- Listed buildings and very compromised plans sit outside these bands
Insist any quote includes a written commissioning sign-off, with measured flow rates at each diffuser within ten per cent of the design figures.
The cheap MVHR quote is almost always the quote that quietly leaves out the commissioning. The premium one is usually the one that survives ten winters without a complaint. The middle ground is rare, and worth being suspicious of when you find it.