Garage gone - house here

Hello, 3 garages will need a new roof in the near future. Since the kids are getting bigger, the idea is now being considered to simply replace them with a single-family house. What rough total sum would you estimate for a one-story cuboid with the dimensions 12x6x4 (LxWxH) Masonry Plumbing Electrical Windows/Door etc...? Thank you very much for participating in the brainstorming. Regards tetris

Hello "favorite game" from earlier years,

Hello,
3 garages will need a new roof in the near future.
Since the offspring is growing bigger, the idea now is to simply replace them with a single-family house.
What amount do you roughly come to for a one-story cuboid with the dimensions 12x6x4 (LWH)
Masonry
Sanitary
Electrical
Windows/Door
etc...?

All together about EUR 80,000 plus incidental costs.

Kind regards