MVHR Installation Costs UK — What to Charge to Supply and Fit a Whole-House MVHR System in 2026

What MVHR Is and Where It Gets Specified

An MVHR system continuously extracts stale, moist air from wet rooms — kitchens, bathrooms, utility and en-suites — and supplies fresh, filtered air to habitable rooms such as bedrooms and living spaces. The two airstreams pass through a heat exchanger inside the central unit, recovering 85–95% of the heat from the outgoing air and transferring it to the incoming fresh air. The result is whole-house ventilation without throwing your heating out of the window.

In UK Building Regulations terms, whole-house MVHR is the System 4 ventilation designation under Approved Document Part F. It is specified where it makes the most sense:

• New builds and airtight homes: once a dwelling is built to a low air-permeability figure, natural ventilation alone cannot meet Part F, and MVHR becomes the obvious route.
• Deep retrofits: whole-house refurbishments and EnerPHit-style upgrades where airtightness has been dramatically improved and trickle vents would undo the work.
• Basement and difficult conversions: spaces with limited or no opening windows where mechanical ventilation is the only practical way to meet ventilation requirements.

The key thing to communicate to customers: MVHR only performs to spec in a reasonably airtight building. Fitting it to a leaky house wastes the heat-recovery benefit and risks cold draughts. Part of your job at quoting stage is being honest about whether the building is suitable.

The Main Cost Drivers

Two identical-looking houses can come in thousands of pounds apart. Before you put a number on anything, work through the factors that actually move the price.

Unit Size and Specification

The central heat-recovery unit is sized to the property's total extract and supply airflow. A small flat may need a compact unit rated for low airflow; a large family home needs a higher-capacity unit. Spec also drives cost: summer bypass, humidity sensors, integral frost protection, higher-efficiency exchangers and quieter EC fans all push the unit price up. Budget units start around £700–£1,200; mid-range whole-house units sit at £1,200–£2,200; high-end or large-capacity units run £2,200–£3,500+.

Number of Rooms and Valves

Every supply and extract terminal is a valve, a length of duct, a fitting and time. A two-bed flat might have five or six terminals; a four-bed house with multiple bathrooms can have ten to fourteen. More valves means more ducting, more drilling, more sealing and more commissioning points to balance — room count is one of the strongest predictors of total cost.

Ducting Type — Rigid vs Radial / Semi-Rigid

This is the single biggest variable in many quotes. Rigid duct (galvanised or rigid plastic, typically 150mm spiral or flat channel) is cheaper in material terms but slower to install, harder to route and unforgiving of tight bends. Radial / semi-rigid systems use small-diameter flexible runs (often 75mm) from a central manifold to each terminal — far quicker to route through joists and around obstacles, quieter, but the manifolds, connectors and proprietary duct cost more in materials. On retrofits, semi-rigid radial usually wins on total cost because the labour saving outweighs the material premium; on new builds with open joists, rigid can still be economic.

Duct Runs, Routing and Building Fabric

How far the air has to travel and what it has to travel through is where jobs quietly blow their budget. Long runs to a loft-mounted unit, routing through engineered joists, threading around steels, crossing cold lofts (which then need insulating to prevent condensation) and getting ducts to roof or wall terminals all add hours. A simple, central plant position with short, direct runs is cheap; a unit in a far corner feeding terminals at the opposite end of the house is not.

Commissioning

Commissioning is not optional and it is not free. Every terminal must be measured and adjusted to its design flow rate, the system balanced supply-to-extract, and the figures recorded for Building Control. On most domestic jobs this is half a day to a full day of skilled time with calibrated equipment, and it is the part inexperienced installers most often underprice or skip — at their peril.

Typical Price Bands with Worked Examples

The numbers below are supply-and-fit totals including a commissioned, signed-off system. They assume the building is suitably airtight and that builder's work (chasing, making good) is either included or clearly excluded — be explicit about which in your quote.

Small Flat or Apartment — £2,500–£4,000

A one or two-bed flat with five or six terminals, a compact unit and short duct runs. Worked example: a two-bed flat with a kitchen and bathroom extract, two bedroom and one living-room supply, semi-rigid radial ducting to a cupboard-mounted unit. Unit £900, ducting and terminals £550, sundries £200 — materials around £1,650. Labour two days plus commissioning, roughly £1,400. Total in the region of £3,000–£3,400 before margin and VAT considerations.

Typical 3-Bed House — £4,000–£7,000

The bread-and-butter MVHR job. Three or four bedrooms, one or two bathrooms, kitchen and utility — eight to twelve terminals. Worked example: a 3-bed semi with a loft-mounted mid-range unit, semi-rigid radial ducting, insulated runs across the cold loft and roof terminals. Unit £1,600, ducting, manifolds and terminals £1,300, insulation and sundries £400 — materials around £3,300. Labour three to four days plus a full commissioning day, roughly £2,200–£2,800. Total typically £5,500–£6,200.

Larger or Difficult Retrofit — £7,000–£12,000+

Large detached homes, awkward period properties, multi-bathroom houses, or retrofits where access is poor and routing is tortuous. Worked example: a four/five-bed retrofit with twelve to fourteen terminals, a high-capacity unit, long rigid-and-radial hybrid runs, lifting and re-laying floors to route ducts, and significant making-good. Unit £2,600, ducting and fittings £2,400, access and builder's work £1,500 — materials and subcontract around £6,500. Labour five to eight days plus commissioning, £3,500–£5,000. Totals from £9,000 up past £12,000 are normal here, and the worst-access jobs go higher.

Labour vs Materials Split

On a typical domestic MVHR job, materials (unit, ducting, terminals, insulation, sundries) account for roughly 45–55% of the total, with labour and commissioning making up the rest. The material share is highest on simple new-build jobs with short runs, and lowest on difficult retrofits where labour and access dominate.

The mistake that kills margins is treating MVHR like a boiler swap — pricing the kit accurately but guessing the labour. Ducting first fix, second fix, commissioning and making-good coordination are where the days go. Price labour off the duct route and terminal count, not the unit box.

Quick Reference: MVHR Installation Prices UK 2026

Commissioning and Flow-Rate Balancing

Commissioning is what separates a working MVHR system from an expensive noise generator. Each room has a design flow rate — supply rates for habitable rooms and extract rates for wet rooms — set out in the system design. After installation, you measure the actual airflow at every terminal with a calibrated anemometer or flow hood and adjust the valves until each one hits its target. You then confirm that total supply and total extract are balanced so the house is neither pressurised nor depressurised.

This data must be recorded. Under Part F, commissioning results have to be provided to Building Control before a domestic ventilation system is signed off. A clean commissioning sheet is also your protection: if a customer later complains about draughts, condensation or noise, your recorded flow figures show the system was set up correctly. Always quote commissioning as a distinct, visible line — never bury it.

Common Things That Push the Price Up

Most MVHR overruns come from the same handful of issues. Check for these before you commit a price:

• First fix / second fix coordination: on new builds and refurbs, MVHR ducting has to go in around the same time as plumbing and electrical first fix. Poor sequencing means return visits, standing time and clashes with other trades — all chargeable, all best flagged up front.
• Duct routing through joists: drilling or notching joists within permitted zones, working around engineered I-joists, and finding routes that don't compromise structure can turn a one-day duct run into three.
• Plastering and making good around terminals: ceiling and wall terminals need cutting in, and the customer or another trade has to plaster and decorate around them. Define clearly whose scope this is — unclaimed making-good is a classic source of disputes.
• Cold-loft insulation: ducts in unheated lofts must be insulated to prevent condensation. It is easy to forget and not cheap to add.
• Roof or wall terminations: getting intake and exhaust through the roof or external wall, with weatherproofing, can need roofing or rendering work you didn't allow for.
• Access and lifting floors: retrofits frequently need floorboards up to route ducts, then relaid and made good — easily a day or more.

How to Quote MVHR

A good MVHR quote is built from the design, not pulled out of the air. Work in this order:

• Confirm the design and airflow: total extract and supply rates, room-by-room. This sizes the unit and tells you how many terminals you're fitting.
• Survey the duct route: where the unit goes, how runs reach each terminal, what they pass through, and where the roof/wall terminations land. This drives most of your labour.
• Choose the duct system: rigid vs radial / semi-rigid based on access and run lengths — and price the material premium against the labour saving.
• Price materials, then labour separately: unit, ducting, terminals, insulation, sundries as one block; first fix, second fix, commissioning and making-good as another.
• List commissioning explicitly: show flow-rate balancing and the Part F sign-off documentation as a named line so the customer values it.
• Define exclusions: state clearly whether plastering, decorating, scaffolding and structural work are in or out. Ambiguity here is where margin disappears.

Quote materials and labour as separate, visible blocks. It shows the customer where their money goes, justifies the price against cheaper installers who skip commissioning, and makes it obvious when a change in scope — a longer run, an extra terminal — should change the price.

Frequently Asked Questions

How much does it cost to install MVHR in a 3-bed house in the UK?

For a typical 3-bed house, expect £4,000–£7,000 supply and fit including a commissioned, signed-off system. The figure depends on terminal count, ducting type and how difficult the routing is.

Is MVHR cheaper in a new build than a retrofit?

Usually yes. New builds give open joists, planned plant positions and short, direct duct routes, so labour is lower. Retrofits often need floors lifting, awkward routing and more making-good, which is why difficult retrofits run £7,000–£12,000+.

Why is the ducting so important to the price?

Ducting and the labour to route it usually cost more than the heat-recovery unit itself. The choice between rigid and radial / semi-rigid, the length of runs and what they pass through are the biggest swing factors in any MVHR quote.

Does an MVHR system have to be commissioned?

Yes. Under Building Regulations Part F, the system must be commissioned — every terminal balanced to its design flow rate and the results recorded for Building Control. Always price commissioning as a separate line; it is skilled work, not an afterthought.

Will MVHR work in a draughty old house?

Not well. MVHR relies on a reasonably airtight building to recover heat effectively. In a leaky house the heat-recovery benefit is lost and you can get cold draughts. Improving airtightness should come first, or the system won't deliver what the customer paid for.