Massive double garage vs. prefab garage vs. carport

Our garage has a paved floor. I think that is also an advantage: we are paving the driveway and the garage floor in one go.

I want to quickly join in here. Our architect has planned a double garage with a storage room (separated) and access to the house. The roof will be a flat roof with gravel. The exterior dimensions are 6m x 9m x 2.6m. He estimates the cost at €300/m³, which corresponds to a hefty €43,000 for the garage. That really shocked us. The prices I see here are all significantly cheaper. Before we now rationalize away or reduce the garage for cost reasons, I wanted to hear your opinion. How do you assess the cost estimate? What would you estimate for a brick garage with the aforementioned dimensions? An alternative would be a precast concrete garage, or to build it ourselves.

For a masonry garage of this size, our general contractor demanded a similar amount. When this was discussed back then, they quoted about €40,000. That was definitely too much for us. For this reason, we switched to a prefabricated garage. If you take a 3-part prefabricated concrete garage, you are at about half the price. It gets even cheaper with metal prefabricated garages...

And it's even cheaper when you make it yourself. If you can. The costs seem to be exploding at the moment because everyone wants to have it like that.

Best regards Joe

Precast concrete garages I have already received offers for the above-mentioned dimensions of €25,000. A foundation is also required. Even then, you would save almost €20,000. Especially since the masonry garage didn’t even include an electric door opener.

How would you estimate the costs for a foundation for a 6x9m garage?