Basement extension: Is approval possible?

Good day,

I intend to break up my old terrace built in 1984 and rebuild it. In this process, I would like to cellar it, as there is a lack of space.

The property has a total area of approximately 680 sqm and there is no development plan. There is only a design plan according to § Bau 34 NRW. It only specifies roof tile color, etc.

In the old building documents, a floor area ratio of 0.6 was assumed. Floor space index: 1.2

Currently, about 180 sqm are built including the garden house and garage. All are 1.5 stories high.

Do I have good chances of getting approval for a cellar extension of about 38 sqm? Or is it not that simple according to the floor area ratio?

I would be very grateful for any tips!!!

Best regards

Mike

You should get approval for the basement extension. As far as I can see, there is initially nothing against it. Why do you want a basement extension and not a ground floor extension? Building underground is much more expensive than above ground and you have less quality of life (light, view, etc.) than on the ground floor.