Orientation and shape of a single-family house - cut the corner for the terrace?

He only has 400 sqm. How is he supposed to include the giant terrace in the floor area ratio?

As mentioned, with knowledge of the property one can give more concrete advice - chamfering a corner does not have to be the only wise conclusion. I do not see the house moving into a different fee zone due to a small corner of this dimension, otherwise that would also have to apply to a hip roof.

Why have a corner terrace at all? If you sit in the south, you also get some of the west sun there.

If you want to enjoy the evening sun in the summer, it's best to go to the north.
Best draw the path of the sun in summer for yourself.
Unless you have now fallen in love with this [abbe] corner...