Ventilation

System D: balanced ventilation with heat recovery

System D extracts air and blows in fresh air at the same time, via a central unit with heat recovery. This unit extracts heat from the extracted air and transfers it to the fresh air coming in, up to around 90 per cent. That way, you don't let all your heat escape outside in winter. System D does, however, require a complete network of ducts for supply and extraction, so it's mainly an option for new-builds or major renovations where you're carrying out work throughout the property anyway. We'll assess together whether it's suitable for your home.

• Both supply and extraction are mechanical
• Heat recovery of around 90 per cent
• Filters block dust and pollen
• Mainly for new-builds or major renovations

What Ahmed does with your ventilation system

The electrical side is a job for an electrician: connecting the unit to the mains, laying the wiring for the sensors and the controls, and fitting the switches. Ahmed mounts the unit, connects up the extraction in the kitchen, bathroom and toilet, and balances the airflow room by room. He runs the ducting as short and tidy as possible, and finishes the vents off neatly in the ceiling or wall. A well-chosen, properly set-up system runs quietly, so you'll barely notice any draughts or noise.

• Connecting the unit to your electrical installation
• Wiring for sensors and control systems
• Airflow adjusted for each room
• Ducting and grilles neatly finished

Mandatory when renovating, and grants

In Flanders, you're required to install a full ventilation system in new-build properties and for major energy renovations. If you're replacing your windows, your home has to demonstrably meet the ventilation requirements; otherwise you won't be eligible for a grant in that category. For properties over ten years old, the reduced VAT rate of 6 per cent usually applies to installation by a contractor, rather than the standard 21 per cent. For the latest grant amounts, it's best to check the official grant simulator, as the rules changed on 1 March 2026. For new-builds and major renovations, a ventilation assessor draws up the mandatory reports. Request a quote, and we'll calculate the indicative price for your property.