Use designated parking space as a garden

In a current new development project by the property developer, terraced houses are being marketed that are offered with either 1 or 2 parking spaces, depending on the size. We are interested in a larger terraced house that is allocated 2 parking spaces. We only need 1 parking space and would prefer to use the area of the second parking space to enlarge the garden area instead (the parking space borders directly on the garden). Therefore, we asked the developer if we could purchase the house with only 1 parking space. The response was that they must designate the house with 2 parking spaces, but they cannot pave the second parking space so that we can implement our idea. Would this be legally acceptable or could there be problems? If problematic, what would need to be done to subsequently "legalize" this project? Many thanks in advance for your help!

Would this be legally okay or could one run into problems here? If problematic, what would need to be done to subsequently "legalize" this project?

Unofficially it is possible, "legalizable" it would probably be through an astronomical compensation payment to the municipality. I would keep this second parking space free of trees and bushes, that should be enough. My grandparents didn’t have a car, on their "parking space" three little Christmas trees were grown.

Spontaneously, lawn grids (the plastic ones) come to mind. It should count as a paved parking space, but it is still green. Alternatively, without plastic, gravel lawn would also work (but I don’t like it when the stones are sticking out everywhere).

I would keep the space free, when the garden is laid out drive the car on it once, mark the spots with the wheels, place four grass grid stones there and done. Then a car could always be parked there.

Yes, exactly: lanes made of grass grid stones, and in between / next to [Paddockmatten].

Thank you for the many feedbacks! Of course, we would prefer if we just pretended that this second parking space didn't exist at all. That means simply adding this parking space area to the garden area and sowing grass everywhere, done! The background is that the garden of this property is somewhat smaller than what we were looking for, but together with the "sacrificed" parking space, it would still be acceptable (because we really like the house and the location otherwise).