: We neither have a development plan nor do we want to build a villa. The house should either be single-story or one and a half stories, simply rectangular and with a gable roof.
I think you misunderstood me:
A "town villa" is a currently modern house type characterized by being square - two stories - with a flat hipped roof. It has nothing to do with "villa" in the sense of a "rich person's house." You could also call it a "instead-of-villa."
A "development plan" is not an elaborate plan for how to decorate the park property with a pool house, gatehouse, and tea pavilion. Rather, it is an official colorful city map of your housing block where unpleasant things are written. For example, whether the gables of your house must face the sides or the street and garden, or whether both are allowed.
Plots in new development areas always have to deal with the fact that such plans were made there. In village centers, they are regularly not in place. Then the neighboring buildings serve as a standard for how houses should look there.
One and a half stories and a gable roof are almost never restricted in development plans; you are almost always allowed to build that. But it may be the case, for example, that a roof pitch of 28 to 35° and a ridge direction parallel to the street is required. And for example, a knee wall may be excluded, so you have to place the wall plate inside the roof.
If by "we don’t have a development plan" you mean that you already have a plot and no such plan applies to it: then the desired house form could only be impeded if, for example, all neighboring houses had flat roofs.