ᐅ Blower Door Test Required for Ventilation Systems and KfW 70 Energy Standard

Hello dear forum members,

the title basically says it all.
We are building a KfW 70 house and have decided to install a ventilation system with heat recovery for comfort reasons. Are we required to carry out a blower door test? Or should we do one in order to properly adjust the ventilation system?

Hello,

As far as I know, a blower door test is only mandatory if both a mechanical ventilation system is installed and funding is being applied for – meaning it is a requirement for the grant.

Otherwise, a blower door test is more of a "nice to have," but these days many construction companies include it as a "quality feature."

Best regards,

Dirk

...because a blower door test (BDT) reveals the leaks in the building through which heat can escape

Only necessary when applying for subsidies... otherwise not...

Hmm... so we do need to build one after all, since we took the KfW70 loan and therefore have access to funding.

That’s how it is
But don’t you want to do the test? After all, gaps in the building envelope can be identified... That is important for the heating season