Calculation of permissible building area according to floor area ratio

Hello everyone,

I am not sure if I have calculated the maximum buildable area on a plot with a development plan correctly. Maybe the experts among you could take a look and correct me if necessary.

- The floor area ratio is 0.15
- Furthermore, it is stated that the permissible floor area may be exceeded by up to 100% by the floor areas of the facilities designated in §19 (4) sentence 1 of the Federal Land Utilization Ordinance.
- (The plot is located in Schleswig-Holstein in case that is important)

1) Does that mean that the floor area of all facilities (house, shed, driveway, terrace) may amount to 30% of the plot area?
2) Or is the 100% excess referring only to the area of the ancillary facilities?

For my calculation, I have followed assumption 1).

Floor area ratio 1
House = 102 m²
Terrace = 44 m²
Sum floor area ratio 1 = 146 m²
Floor area ratio 2
Shed = 17 m²
Parking space/carport = 35 m²
Driveway = 20 m²
Access (path to the front door) 8 m²
Sum floor area ratio 2 = 80 m²

Total floor area ratio = 226 m²

Plot = 865 m² => of which 15% + 100% excess = 30% results in a maximum permissible building area of 259.5 m²

Total floor area ratio is thus below the maximum permissible building area.

- Is this assumption basically correct?
- Is the division of facilities into floor area ratio 1 and floor area ratio 2 correct?

Thanks in advance for your help.

Regards Björn