Insulation of heating room and covered passage

Good day,
I am new here and would like to introduce myself first.
I am Alex, 24 years young and recently proud homeowner.

Since a heating system renovation is due at the latest in 2020, I want to make some changes to the building envelope beforehand.

In the attached photo, you can see the passage from the garden to the street. Protected from rain, but directly exposed to outside air. Above it is, among other things, the bathroom with underfloor heating, which is why I want to insulate there. So far, there is nothing installed there.
The annex was built with 24 cm Ytong. I plan to install 160 mm 032 EPS insulation with a step joint there (if there is enough space, I have to measure). Is there any reason against this?

At the same time, to the right of the passage is the heating room. This room, as well as the entire ground floor, which serves as a cellar, is not insulated upwards towards the apartment.
Can I also safely install insulation there?
Space-wise, 160 mm will also fit in the heating room; unfortunately, in the rest of the "cellar," only up to 100 mm is possible.

Is this possible without any problems, or does it pose any risks?

Thank you very much for the answers in advance and already a Happy New Year 2019!

Alex

I would initially seal the passage on both sides with reasonably tight and somewhat insulated doors. There is no objection to EPS on the "basement ceiling." However, one could possibly also use PUR and save some height. Intuitively, I prefer mineral wool in the touchable interior area and it might also be a bit more forgiving when bonding to a very likely uneven ceiling.

If you actually have that much space, I might also consider insulating in 2 layers. This minimizes thermal bridges caused by gaps between the boards. It becomes especially great if you provide "rising" walls (i.e., those continuing in the upper floor) with an apron, meaning the ceiling insulation is extended down the wall a bit. There are even special insulation wedges for this.

Hello, thank you very much for the response. I want to avoid going through there since, among other things, wood is stored there. The only really uneven ceiling is in the heating cellar; mineral wool would probably even make sense there. The remaining ceilings are all very even. I have read about the apron, but I would actually like to avoid it – otherwise, I would have a step on every wall, which looks very bad. Your objection to PUR – which insulation board would you choose there? Currently, I had the following in mind: [Link entfernt] For the heating room then for example: [Link entfernt] Do I have to consider anything there because of moisture, or can I plaster the mineral wool normally?

In the end, it's a question of priority; for a bit of wood that could also be placed elsewhere, I wouldn't want to burden myself with this additional cooling (especially just below the bathtub).

The apron is not a must, but as mentioned, to avoid this "step" there are wedges made specifically for that purpose.

Regarding the insulation board: Left side is not allowed here, but just search for "Kellerdecke PUR," and you'll find the right thing. You can also, if in doubt, simply call online shops and ask for advice. Or look for a local insulation material dealer in your area; they are often much cheaper.

Mineral wool for ceiling insulation is available in various types. From "very rustic" to "finished surface," depending on the level of demand and desired further processing. The rustic type can (but of course doesn’t have to) only be painted afterwards, or plastered first and then painted. However, this is purely for aesthetic purposes and has no effect on the function.