Regulations regarding development plans, any experiences?

Hello,

I urgently need support in interpreting some regulations according to the development plan.

The property has a size of 780 sqm.

Requirements according to the development plan:
Building type: single-story
Floor area ratio: 0.3
Floor space index: 0.35-0.45

I understand this to mean that I may build on a maximum of 30 percent of the property area.
But how can the floor space index of at least 0.35 be explained? That would mean that I must build a house with a size of at least 35 percent of the base area, since only full floors are counted and according to the development plan only single-story buildings are allowed on this property.
Wouldn't the floor area ratio and the floor space index then contradict each other?

For better illustration, I have attached a photo. Thank you very much for the help / experiences and have a nice evening!

Regards

Hello Dutch,

for the calculation of the floor area ratio, the [Baunutzungsverordnung] applicable at the time the development plan was made available must be used. If the development plan was, for example, made available in 1985, the floor area ratio must be calculated according to the [Baunutzungsverordnung] of 1977, meaning the ground floor area of all full floors plus the areas of the living rooms on other floors.

However, if the development plan is more recent, the written provisions should be examined to see whether they prescribe calculation methods differing from the [Baunutzungsverordnung 1990 (2013)]. If this is also not the case, check whether the author of the site plan has correctly adopted the provisions from the development plan.

Otherwise, I see it exactly as you do, that the provisions of the development plan contradict each other.

Hello Escroda,

thank you very much for the quick response. So the development plan is from January 1994. Nothing is mentioned about the floor area ratio and plot ratio in the written stipulations of the development plan. A mistake by the author when transferring data to the site plan can be excluded; it is stated exactly the same way in the development plan. Very strange all...

Hello Dutch,

what is strange, however, is that a usage boundary runs through your property. What do the regulations look like south of the line? Is 0/20 supposed to be the roof pitch? I haven't seen that before.

Then probably only an inquiry at the municipality will help.

No, it does not contradict itself. With 780 sqm, you are allowed to build a footprint of 234 sqm with a one-story house. Therefore, the attic must be smaller than 1/3 or 1/4 (depending on the federal state) of the lower living area, which has a height of over 2.00 meters. With a floor area ratio of 0.35 and a house making maximum use of the floor space ratio, the area above with a height of at least 2 meters may only be 273-234=39 sqm, with a floor area ratio of 0.45 correspondingly more.

However, User Escroda is probably right as a surveyor engineer, I have only just seen his answer.