Floor area ratio; § 19 para.4 Building Use Ordinance - experiences?

The exceptions are clearly marked here: in WA1 for cul-de-sac properties, there is a permissibility of exceeding the floor area ratio - without limit - for driveways; in WA2 and WA4 for terraces, limited to an additional 0.1 floor area ratio.

An outbuilding (garage or similar) is neither a driveway nor a terrace, the property in question is in WA1, so that says it all.

How do you come to the position that the development plan has to practically tick off or cross out every single sentence of the Building Use Ordinance?

You seem to be very knowledgeable,

The expert in this field would be - I can only read and remember that planning law is not a wish concert.

As far as I have been explained, the rules of the Baunutzungsverordnung for the respective type of development area are always part of the development plan. If one wants to deviate from the provisions of § 19, this must be done through determinations.

Of course, you should secure yourself there. But honestly: If the development plan explicitly facilitates the construction of double garages for small plots compared to the [Baunutzungsverordnung], why should it then significantly complicate the construction of garages compared to the [Baunutzungsverordnung] in other places?

Oh yes: If the Baunutzungsverordnung regulations are restricted, this must also be justified in the appendix. The OP should take a look there.

Thank you very much for the answers!

Oh yes: If the Baunutzungsverordnung regulations are restricted, this would also have to be justified in the appendix. The OP should have a look there.

I haven't found anything about a restriction.... Then call the city.

If one wants to deviate from the provisions of § 19, this must be done through determinations.

The development plan does not need to list individually which possible relaxations it does not want to exploit: not listing them also excludes them. Terraces are listed and garages are not, which means: only terraces are meant and that's that. It does not have to discuss garages separately again.

If the development plan explicitly facilitates the construction of double garages for small plots in deviation from the land use ordinance,

Where does it do that? — if you mean §7.2: that concerns the garage courts of the groups of houses — moreover in other sections of the development plan area.

If the land use ordinance regulations are restricted, this would also have to be justified in the appendix.

The municipality does not have to justify its urban planning intent. If it did not deviate from the maximum framework of the land use ordinance, the non-adoption of a development plan would be completely sufficient.