Carport parking spaces smaller than planned - tolerate?

During the construction of a new multi-family house, the construction company also built a carport with two parking spaces. According to the architect's plans, they were supposed to have an internal measurement of 5.30m, that is, 2.65m per parking space. The carport roof connects on one side to a prefabricated garage and has metal supports on the other side. From the prefabricated garage to the supports, there are now only 5.15m because the supports were set significantly inward. So, 15cm are missing... for me, far from any tolerance. Whether this is technically necessary, I do not know, but then the roof should simply have been made larger so that the internal measurement is maintained. The plan was actually a wall all around, which is only open at the upper section. However, the end product is open all around and then has metal supports down to the ground on one side. These supports are also positioned in such a way that the door cannot be opened because there are two supports there. Effectively, it is like having a wall here. This whole situation is very frustrating because the parking spaces in the underground garage are already only 2.50m wide, and we had planned the carport for a wider/larger car. Is there any way to take action now?

And who are you in this context: the developer of the entire apartment building or the buyer of a residential unit from the [Bauträger]?

Buyer of a residential unit from the developer. There are only these two carport spaces, the other belongs to another buyer of a residential unit.

It would also be interesting to know whether you alone have the right to use the carport. Or: did you buy the parking spaces and have the carport built there by the BT yourselves? Are you the client?

The two carport spaces are sole property. We have purchased one space and another owner of a residential unit has the other. The entire apartment building, including everything such as parking spaces etc., was built/planned by the construction company and then the individual "things" were sold... we did not "order" the carports separately.

I have never heard of specific dimensions being guaranteed as a property for parking spaces regardless of the size of the residential complex. 2.65 m is after all more than 2.50 m, and supports in underground garages, for example, are also not placed where they look best. Buyers are not builders, and "the quantity of 1 parking space" is what you have received.