ᐅ Controlled ventilation system in a bungalow: Is it necessary to lower the ceiling?

Hello everyone,

We are currently finalizing the building permit / planning permission application for our construction project (a bungalow with 135 sqm (1453 sq ft)). We would like to have a ventilation system installed in our bungalow. In this context, our general contractor (GC) recently approached us and said that the ceiling would need to be lowered to install the ventilation system. This means we would have to increase the room height, and this must be taken into account in the building permit / planning application.

There are several issues with this whole process:

• The GC’s subcontractor installs only Zewotherm systems; the cost estimate is 18,000 euros. On top of that, there would be additional costs for increasing the room height. From what I read here, in other forums, and hear from acquaintances, the cost for a ventilation system (e.g., Zehnder or Vaillant) including installation is more around 12k. (We originally thought we would have to build a one-and-a-half-story house; in that case, the Zewotherm system was even offered to us for 23k.)
• We do not want a Zewotherm system but prefer Zehnder (Vaillant would also be possible) – so now we have to find a suitable contractor ourselves who installs Zehnder systems.
• We don’t understand why the ceiling must be lowered to install a ventilation system in a bungalow. Has anyone had experience with this? Is it always necessary to lower the ceiling? What if the system is installed in the floor? Would the floor then need to be raised? I’m afraid our GC simply doesn’t really know much about ventilation systems... but maybe I’m wrong.

So: Has anyone installed a ventilation system in a bungalow without lowering the ceiling?