Ventilation Design According to DIN 1946-6: When Is It Mandatory?

1. What is a ventilation plan?

A ventilation plan is a design framework for ensuring adequate air exchange in buildings. The goal is to prevent moisture damage and mold growth, as well as to meet the minimum hygiene requirements for indoor air quality. This involves determining whether the necessary ventilation can be achieved solely through user behavior (window ventilation) or whether mechanical ventilation measures are required—for example, through the use of ventilation systems.

2. What is the legal basis for this?

Building Energy Act (GEG) – Requirements for Energy Efficiency and Airtightness;

“Buildings must be constructed in such a way that the heat-transferring envelope, including the joints, is permanently sealed against air leakage in accordance with recognized technical standards.
At the same time, a sufficient minimum air exchange rate must be ensured for health and heating purposes.”

The GEG sets forth two key requirements:

• High airtightness in buildings (for energy savings)
• Ensuring adequate air circulation (to prevent moisture buildup and for hygiene)

DIN 1946-6 Standard for Residential Ventilation

This provision describes the requirement for a newly constructed or renovated building to have a ventilation plan and specifies how this minimum air change rate must be verified:

• How to Calculate the Required Air Change Rate
• which ventilation levels should be taken into account
• When a ventilation plan is required

 3. When is it necessary to develop a ventilation plan?

A ventilation plan is required in accordance with DIN 1946-6:

• For new construction ( always, as a general rule)
• For existing buildings:
  • if more than one-third of the windows are replaced
  • or more than one-third of the roof area is retrofitted to be airtight
  • or the facade is insulated

In these cases, the building's airtightness changes significantly, so it is necessary to check whether natural ventilation is still sufficient.

4. Free Ventilation Design from Marley Deutschland GmbH

You know how you live. Leaf Ventilation knows what’s still missing. Every apartment and every house is different—and has different ventilation needs. For example, a family needs more air exchange than a single-person household. Other factors must be taken into account when planning and designing your ventilation system. Based on the information you provide, we’ll reliably develop a customized ventilation plan in accordance with DIN 1946-6 and put together the necessary system components for you.

Here's how it works:

• Fill outthe " " project questionnaire at
  → Enter all relevant building data
• Provide construction drawings
  → Floor plans, cross-sections, elevations (depending on the project)
• Send us your documents
  → We will develop a ventilation plan for you in accordance with DIN 1946-6

Upon request, we can also prepare a positioning proposal for you.

Please send the completedproject questionnaire to and the construction plans to lueftungsplanung@marley.de

Take advantage of: Fast turnaround, standards-compliant planning, and practical solutions!

To learn more about government funding, here.