ᐅ Semi-detached house - Built in 2000 - Is ventilation recommended or necessary?

Hello everyone!

As mentioned in another thread, we are currently renovating our "new" old semi-detached house built in 2000.
https://www.hausbau-forum.de/Heizung-klima/9103-Doppelhaushälfte-bj-2000-heizkonzept.html

What will be done:
- Underfloor heating
- Cavity wall insulation
- Roller shutter box insulation
- Very effective and thick roof insulation
- New heating system (decision still pending)

My partner and I both work full time. Therefore, we can only ventilate continuously at night (not very efficient) and again in the evening.
During the day, this is mostly not possible due to absence. Possibly a dog will stay in the house as well – in that case, continuous ventilation would of course be a good option.

We can definitely handle the installation ourselves.

However, we have very little knowledge about this. For cost reasons alone, we have considered a decentralized ventilation system.
We would ventilate the bedrooms, living room, and kitchen through this system. Bathrooms would be ventilated manually.

What do you think about this, and what price range do these units typically fall into?
Heat loss should naturally be avoided.

Many thanks
Tobias

You should have your semi-detached house evaluated by an energy consultant – I believe these renovations you are planning should be considered as a whole. Which measures are necessary, which are optional? What is truly effective? Does your Vitodens already need to be replaced?

I mean: we are talking about a house from the year 2000 – not from the 1950s 🙄

Good evening and thank you for your feedback.
Where can we find an independent and reliable energy consultant? They should be product-neutral.

The Vitodens 300W from Viessmann is just a suggestion from us since the current heating system is already 14 years old, has had little maintenance, and is therefore faulty. Installing a new heating system along with insulation and ventilation would allow everything to be coordinated together and would likely be a worthwhile investment overall.

How can you recognize a good energy consultant?

Best regards,
Tobias

eXtremeTK schrieb:
Good evening and thanks for your feedback.
Where can we find an independent and reliable energy consultant? They should be product-neutral.

I’m not sure. I’m just an informed homeowner myself. Maybe check with your gas supplier, Google, or consumer protection agencies?
What I do know is this: I would prefer to avoid all that ventilation technology if it were still possible today. Unfortunately, the regulations for new builds are so strict.
With a resale property, you have a bit more flexibility… when I still had our single-family house from the 1970s, I was aware of both the downsides and benefits of drafty windows 😉
What I’m trying to say is: with a house from this millennium, it’s questionable whether it pays off…