Custom ventilation plan: guide, rules & local approach

Imagine: you invest in a brand-new ventilation system, but soon you experience complaints about drafts, dry air, or stubborn lingering odors. Chances are it went wrong in the design phase. A standard ventilation plan starts from minimum requirements, but does not take into account how your home actually breathes. A custom ventilation plan translates your specific situation into an optimal indoor climate.

What exactly is in a ventilation plan?

A professional ventilation plan is much more than a sketch of some pipes. It includes:

• A floor plan with exact positions of supply and exhaust openings per room.
• Calculation of the air volumes required for each room, tailored to the number of users and the function (e.g., bedroom vs. kitchen).
• An isometric diagram showing the heights and connections of ducts in 3D.
• Use of symbols according to standard, so that every contractor can read the plan correctly.
• Choice of the type of ventilation system (e.g., system C or D) with justification.
• Indication of any silencers, filters and control technology.

A good plan forms the basis for correct installation. Without a plan, you risk supply and exhaust being out of balance, leading to uncomfortable indoor climate or even structural damage due to condensation.

Requirements in Flanders since 2016

In Flanders, a ventilation plan is not just a recommendation, but a legal requirement. Since 2016, every newly built home and every building undergoing a major energy renovation (IER) must have a ventilation plan that complies with EPB regulations. This plan must be submitted with the permit application. Strict requirements also apply to residential care centers because vulnerable residents benefit extra from constant, healthy air quality.

Always check with your municipality whether a ventilation plan is required for your project. Our advisors know the local rules and guide you from A to Z.

Make your own ventilation plan or hire an expert?

With some technical knowledge and free software, you could theoretically draw up a plan yourself. However, in practice we often see that DIY plans do not meet the standard or prove unworkable. The pitfalls: incorrect flow rate calculations, underestimation of resistance in long ducts, or conflicts with other systems (electricity, heating). A ventilation specialist thinks beyond just ventilation: he coordinates the system with the entire home. Moreover, you have the guarantee that the plan will be approved in the EPB declaration.

Absolutely want to tackle it yourself? Then choose proven self-build kits that supply ready-made components with an accompanying plan. Keep in mind that you remain responsible for correct execution.

Different systems, each their own plan

A custom ventilation plan selects the most suitable system. The most common types:

• System C+: mechanical exhaust in wet rooms, demand-controlled via sensors. Often combined with recessed ducts or sleek spiral ducts that are concealed in the screed or ceiling.
• System D: balanced ventilation with heat recovery. Requires a more complex plan with supply and exhaust ducts, but yields the highest energy savings. Brands like Solyd offer complete D packages with a plan.
• Decentralized ventilation: ideal for renovations without roof penetrations. Works with separate units per room. The plan focuses on minimal interventions and simplicity.

Our approach translates your wishes and budget into a system that fits like a glove.

Why a custom plan pays off

A plan that starts from your specific situation delivers tangible benefits:

• Lower energy bill: because the system is not oversized and makes optimal use of heat recovery.
• Quieter and more comfortable: no annoying air currents or noise nuisance because flow rates are exactly right.
• Healthier air: correct extraction of moisture, CO2 and pollutants prevents mold and allergies.
• Future-proof: the plan takes into account possible later modifications such as an extension or solar panels.

Our local approach in Flanders

As the only ventilation specialist that combines clear explanations with a true local approach, we understand that every home and business breathes differently. That's why we don't send an external salesperson, but an experienced installer from your region who knows your neighborhood and building style. They come on site, take measurements, discuss your wishes, and draw up a custom ventilation calculation. This way you don't get a standard answer, but a plan that is correct down to the smallest detail. Request your free quote today and experience the difference.