Small cultivation planning - maximum 15 sqm

So the architect and the building authority have coordinated and found a solution. It was remeasured and now I am waiting to see how it looks and how it will proceed.

Hello again. Yesterday the acknowledgment of receipt from the building authority arrived, now it can surely only be a matter of months until it continues... I have received a first offer from a structural engineer for the statics and reinforcement, and the non-binding proposal amounts to a hefty 3500 euros. Yes, the hillside location and the 2 openings also need to be calculated, but it seems a bit much to me. Or is that a fair price? Then already 7000 would be gone before even a single hand has been raised. Maybe I should give up on organizing everything myself and find a small developer who has the time and desire to do everything?

Hello again,
It went quickly, the building permit has been granted. Because I am having trouble finding a structural engineer, I asked the architect and he said he will take care of it during the specification of services and tendering. Do you think it makes sense to use this service for such a small project or just continue searching on my own until I find someone who is willing to take on the implementation? We are a bit clueless because our two houses are existing properties and we have never dealt with something like this before. Any ideas or what should be considered when someone is interested? We basically only have the approved building application....