Help needed for conservatory extension

hello everyone

I would like to have a conservatory built. Now I am looking for people who want to share their experiences with me regarding the base slab and partition wall.

This is my situation. When I look at my not-yet-existing conservatory from the front, we want to build a wall on the neighbor’s plot to which the conservatory will be attached. I thought of a KSV wall with 12cm stones and approximately 5cm insulation on both sides, plastered, with the wall running at an angle about 15cm above the roof structure.

1. Is the thickness of 12cm KSV sufficient for a wall height of about 235cm to 265cm?
2. Is 5cm insulation enough for sufficient thermal insulation? And what material would you recommend?

The foundation:

I have already read and heard so much, but in the end, I am still at square one. I have imagined it like this: since the underground garage ceiling lies about 50cm below the seating area where the conservatory is to be built, I have thought as follows:

I will make a strip foundation with concrete formwork stones from the hardware store, which I will layer as seen from the garage ceiling as follows: first, a layer of Isover Styrodur 40mm thickness to protect the ceiling waterproofing, then the formwork stones will be placed and reinforced with 10mm rebar and filled with screed concrete. Then I would remove the seating area as far as I need for my substructure and then compact it. I have imagined the build-up from bottom to top as follows:

1. Isover Styrodur 100mm
2. Concrete base slab 150mm (no idea what kind of concrete I need?)
3. 2mm thick PE foil for moisture barrier
4. Dry fill by Knauf or similar up to desired height
5. Fermacell board
6. Maurexin Austrotherm UNIPLATTE 10mm
7. Electric underfloor heating embedded in leveling compound
8. Tiles

By the way, the base slab will be separated from the house wall with Syropor 5mm and should rest on the formwork stones on the other side, forming a kind of lying L shape.

Is this okay or completely over the top? I would like to use the conservatory with insulating glass and a thermally non-separated structure also in winter. The wall would be built on the base slab, by the way.

Hope you can help me.

Best regards

you asked quite a few questions :-) first, here are a few counterquestions, since I still can’t really quite picture it... should the conservatory be freestanding? is one wall of the conservatory supposed to block you off from the neighbor? so you only have two walls with glass surfaces because one wall faces the neighbor and the other faces into the house? if I understood that correctly, then that means you basically don’t need to spend too much on thermal insulation, average is enough, since the heat radiation is calculated according to the square meters of glass... the orientation for the conservatory is also interesting so for the insulation material I would either use rigid foam or hemp, depending on your ecological motives... hemp is almost as good, just more environmentally friendly... 5 cm should be enough given the small glass area the thickness of the wall seems sufficient in any case, it doesn’t have to carry anything, since the wall is not freestanding, height shouldn’t be a problem either, I think... before we get to the foundation... have you already obtained all building permits?

hi

I would agree with the hemp, as you can have some problems with moisture (condensation) in the conservatory, because the sun evaporates everything and when it cools down again
phew

but that's exactly why hemp is excellent as internal insulation
rigid foam is probably similar

how does the ventilation actually look?

so first of all thank you for your interest

the house is an end terrace house, the orientation is towards the west, the building permit should not be a problem. for ventilation, slots are planned with a roof exhaust fan.