Ventilation system C vs D (balanced): what does it cost in Belgium in 2026?
Short answer: According to Belgian price guides, ventilation system C costs roughly €1,500 to €5,000 installed and system D with heat recovery €3,500 to €9,000 for a standard build, up to €15,000 for thermodynamic versions. In renovation, expect about 20 to 40% on top because the ducts are fitted afterwards. A 6% VAT rate can apply if the home is over 10 years old.
Prices in this article are indicative Belgian market ranges, not Alpha Services Benelux's price list. Your fixed price is in the quote.
System C vs D: the difference and the installed price
System C (mechanical extraction, natural supply through vents) is the simpler, lower-cost mechanical option; system D (mechanical supply and extraction with heat recovery) costs more: according to Facq, a humidity-controlled C or C+ is two to three times cheaper than a D. Sources differ on VAT basis and finish level, so read the table source by source.
| Source | System C | System D | Note |
|---|---|---|---|
| Facq | €1,500 – €3,500 | €4,000 – €9,000; thermodynamic up to €15,000 | C price incl. VAT; D basis not stated |
| Prijs-Ventilatie.be | €1,500 – €5,000 (C+: €1,800 – €5,500) | €3,500 – €9,000 standard; €4,500 – €11,000 premium | Installed, incl. 21% VAT, depending on home type |
| Bobex | €3,000 – €3,500 (C/C+) | €5,500 – €7,000 (D with heat recovery) | VAT basis not stated |
| Bobex (French-language page) | – | Static €3,000 – €6,000; thermodynamic €6,000 – €15,000 | Excl. VAT |
What does the extra money buy? According to Facq, system D recovers 85 to 95% of the heat and saves €300 to €500 a year on heating. It also filters incoming air, which helps with allergies or a busy street. System C has no filtering, and in a well-insulated home the unheated incoming air can cause draughts near windows.
Price by home type
For a 120 m² terraced house, Prijs-Ventilatie.be gives €2,000 to €3,500 for system C and €4,500 to €6,500 for a standard system D. The larger the home, the more valves and ductwork.
| Home type | C | C+ (humidity-controlled) | D standard | D premium |
|---|---|---|---|---|
| Apartment 80 m² | €1,500 – €2,500 | €1,800 – €2,800 | €3,500 – €5,000 | €4,500 – €5,800 |
| Terraced house 120 m² | €2,000 – €3,500 | €2,500 – €4,000 | €4,500 – €6,500 | €6,000 – €8,500 |
| Semi-detached 150 m² | €2,500 – €4,000 | €3,000 – €4,500 | €5,500 – €7,500 | €7,000 – €9,500 |
| Detached villa 200 m² | €3,000 – €5,000 | €3,500 – €5,500 | €6,500 – €9,000 | €8,000 – €11,000 |
The same source notes a regional effect: Brussels 10 to 20% more expensive, Limburg 5 to 10% cheaper.
What drives the price in renovation
In an existing home, duct routing is the biggest unknown: Prijs-Ventilatie.be puts labour and materials 20 to 40% above new-build on average, because ducts must be fitted afterwards. System D needs space in false ceilings or casings; if that is not possible, Facq says a humidity-controlled C or C+ is often the realistic choice.
| Item | Indicative price |
|---|---|
| Heat-recovery ventilation unit | €1,500 – €2,800 |
| Ducts | €1,200 – €1,800 |
| Valves and grilles | €400 – €700 |
| Labour | €1,000 – €1,600 |
| Balancing and report | €350 – €600 |
- Drilling through concrete: €80 to €180 per hole.
- CO₂ demand control: €400 to €1,200 extra, with 25 to 40% lower yearly energy consumption according to the same source.
- Acoustic damping: €200 to €450 extra.
- Unit: budget units from €1,200, premium models €1,800 to €2,800.
A balanced system in a draughty, poorly insulated home delivers much less. Have a professional assess the building envelope first.
Maintenance and long-term cost
System D needs more maintenance than C, though it stays modest: replace filters once or twice a year. For C, Facq says cleaning the vents once a year is enough.
- Service visit: Bobex quotes €200 to €350 per visit (VAT basis not stated); duct cleaning is usually needed every 3 to 5 years.
- Over 20 years: Prijs-Ventilatie.be counts €200 of maintenance and filters for C, €400 for C+ and €1,600 for D.
- Official view: the Flemish Department of Environment confirms system D needs more maintenance than systems A, B and C.
Dirty filters reduce efficiency and air quality. According to Bobex, a maintenance contract works out cheaper over time than separate visits.
What is mandatory: EPB, new-build and renovation
The type of work sets the requirements: according to the 2026 Flemish EPB brochure, they differ for new construction, ordinary renovation and deep energy renovation (IER). New builds and IER need a complete ventilation system; ordinary renovation faces lighter requirements.
- Flanders: for new construction and IER, a ventilation reporter must also be appointed and a start declaration submitted.
- Ordinary renovation: requirements depend on the type of work and the year of the application. Have your architect or an accredited EPB reporter confirm them before you pick a system.
- Brussels and Wallonia: the PEB rules differ by region and type of works; ask your PEB adviser what applies to your file.
Facq notes that ventilation is among the most common non-compliances at EPB inspections. A properly balanced system with a measurement report avoids disputes later.
6% or 21% VAT on ventilation
When renovating a home older than 10 years, VAT can be 6% instead of 21%. Conditions according to Bobex: the home is over 10 years old, used only as a private residence, and the same contractor supplies and installs the system. Materials you buy yourself stay at 21%.
Prijs-Ventilatie.be illustrates the difference: on €3,000 excl. VAT you save €450; on €5,000, €750; on €7,000, €1,050. Always ask whether a quote is excl. or incl. VAT and which rate was applied; more detail in our guide to 6% VAT on renovation.
Grants and loans change regularly: check the current situation on the official regional portals (vlaanderen.be, wallonie.be and Homegrade via homegrade.brussels).
Comparing quotes without surprises
Only compare quotes that cover the same scope: same home, same system type and the same VAT basis. A low-priced quote without ductwork or balancing is not a real saving.
- Which type (C, C+, D), which unit and which filter class?
- Number of valves and vents, and where do the ducts run (false ceilings, casings)?
- Are drilling, making good and finishing included?
- Are balancing and the measurement report included?
- What does maintenance cost, and how often are filters replaced?
- Is VAT 6% or 21%, and under which conditions?
If ventilation is part of a wider interior renovation, a site visit is essential to judge the duct route. Alpha Services Benelux, a contractor with its own team and active since 2014, works with a fixed written quote after a site visit; see also our renovation page or call 0485 44 55 12. The amounts on this page are market ranges, not the price list of Alpha Services Benelux.
Fixed quote after a site visit
Alpha Services Benelux does the work with its own team, active since 2014. VAT BE 0541.320.178.
Request a quoteFrequently asked questions
How much does a system D ventilation cost in Belgium?
For a standard system D with heat recovery, sources give €3,500 to €9,000 installed (Prijs-Ventilatie.be), €4,000 to €9,000 (Facq) and €5,500 to €7,000 (Bobex). Premium and thermodynamic versions reach €11,000 and €15,000. VAT basis and home size explain the gap.
What is the price difference between system C and D?
System C costs roughly €1,500 to €5,000, system D €3,500 to €9,000 for a standard build. Facq calls a humidity-controlled C or C+ two to three times cheaper than a D. D recovers 85 to 95% of the heat and filters incoming air; C does neither.
Can I fit system D in an existing home?
Yes, if there is room for ducts in false ceilings or casings. Renovation costs on average 20 to 40% more than new-build (Prijs-Ventilatie.be). If the ducts cannot be routed without major work, Facq says a humidity-controlled C or C+ is often more realistic.
How much does system D maintenance cost?
Bobex quotes €200 to €350 per service visit, with duct cleaning every 3 to 5 years. Filters are replaced once or twice a year. Over 20 years Prijs-Ventilatie.be counts €1,600 of maintenance for D versus €200 for C.
Does 6% VAT apply to ventilation?
Possibly, if the home is over 10 years old, privately used, and the same contractor supplies and installs the system. Materials bought separately stay at 21%. On €5,000 excl. VAT the saving is €750 according to Prijs-Ventilatie.be.
Sources
- Systeem C of D: welke mechanische ventilatie kiezen voor uw woning in België? — Facq
- Prijs ventilatiesysteem in België (2026) — Prijs-Ventilatie.be
- Kosten ventilatiesysteem: richtprijzen, types en premies — Bobex
- Prix d'un système de ventilation pour maison — Bobex (FR)
- Ventilatiesystemen — Departement Omgeving, Vlaanderen
- Nieuwe EPB-eisen voor nieuwbouw en renovatie 2026 — Vlaanderen (VEKA / Departement Omgeving)
- Energy performance legislation for new construction and renovation (EPB) — Vlaanderen.be