150 kg/m² load capacity for garage roof with option for roof terrace?

I am still not a structural engineer, but I recommend consulting one.

If you feed Wikipedia with the term payload, you will find a live load of 4kN/sqm for roof terraces.

That means (expressed incorrectly) 400kg/sqm AFTER floor construction. So 400kg PLUS paving slabs, substructure, waterproofing membranes, insulation, etc. So presumably you should be able to manage with 600kg/sqm. It's almost the same as proposed by the architect. It will be fine.

!!! ACHTUNG LEBENSGEFAHR !!!

Which intermediate ceiling in the house can hold 150kg/sqm?

Every floor ceiling made of concrete. If there is a balcony on it, even 350. No joke: this is required because coal briquettes were still stored on the balcony during the imperial era. The same regulation should apply to the roof terrace.

You did not understand the meaning of my question. I really hope it can carry significantly more.

And with 3.5kN you probably won’t get a balcony approved in Germany anymore, whether with or without briquettes. Under 4.0kN, not much should be possible anymore.

150 kg/ m² is not much, 2 adults dancing would already break through if it weren't reinforced concrete...(floor slab)

When I see what our sliding door wardrobe weighs empty, plus the laminate... I'm glad the ceiling holds more than 150 kg/ m²

I just discussed the same issue with my prefabricated garage and already talked to the manufacturer. Initially, we planned a load of 250 kg / m² (Allgäu) due to snow load, but after expressing the wish to possibly build a roof terrace here later, the recommendation was definitely to increase it to 500 kg / m². The construction company, by the way, shared the same opinion. The additional cost from 250 to 500 was € 250.00 net. So not a big deal.

Surcharge from 250 to 500 was, by the way, €250.00 net. So not a big deal.

For the entire roof area (single or double garage)? - with which roof construction?