Zapf prefabricated garage is being widened

Hello dear community.
This is about our Zapf prefabricated garage that we want to widen into a large garage.
Since demolition and complete rebuilding is much more expensive, we want to attempt the conversion in spring.
A master mason drew the sketch for me. The main work consists of supporting the precast concrete ceiling.

The mason has 15 years of professional experience and said that the conversion can be carried out like this.
For space reasons related to the garage height, the concrete ceiling rests on the HEM 140 beam.

In the end, a ring beam and a 30⁰ pitched roof will be added. The eaves side faces the gate. Snow load zone 1.
For weight reasons, the gable sides will be made from a wooden beam construction, clad with boards.
Maybe someone knowledgeable could take a look at this and comment.
Of course, I am available for questions.

Just sell the Zapf garage as it is. It probably came with a crane and low-loader. That way it can be moved again. Maybe someone from the area needs such a garage and will pay a good price. Then rebuild.

Everything else is patchwork.

Just sell the Zapf garage as it is. It probably came with a crane and low loader.
That way it can be moved again. Maybe someone from the area needs such a garage and will pay a good price. Then build new.

Anything else is patchwork.

The garage has been offered for free on the internet for 9 months.
Nobody wants it.
The problem is that the garage is 3.6m wide and not every freight company is allowed to transport that. Plus you need the 200 ton crane.

And I wouldn't call it patchwork. You don't tear down the whole house if you want to add a storey. And if the static is okay, why not?

It is clear to me that the transport will be expensive.

But still, I wouldn't do it the way you imagine. You practically want to remove a side wall. That would ruin the entire stability of the garage because it’s not built with masonry. These are steel-reinforced and cast concrete prefabricated parts. The reinforcement goes around the corners, etc.
Then you probably don’t really have a good foundation beneath it. The Zapf garage will have a completely different load on it, where the bonding is still missing.

Nevertheless, it might still be possible to try somehow.

What would be a deal-breaker for me is the height. If you want to put a small stage in, even if it is just a short-lift stage, you just won’t fit. Or if you buy a van or something like that. So if you're going to do it, do it right.
The garage is the most important part of a house for a real man. And it can never be big enough.

can never be big enough.

Real men don't need to compensate with extra large garages, cars, watches, etc.

Renovators like you, of course, sit every evening in a turtleneck and slippers promptly at 8 in front of the TV so as not to miss the [Tagesschau]. For that, a perfectly fitting prefabricated garage is of course enough. However, for many, it is the second, if not the first living room. And there you want to have it a bit cozy as well.