How to calculate square meters on the upper floor?

[StorSegelbåt]

How do you calculate the square meters of the upper floor in a 1 1/2 story house? The ground floor is 95 sqm. If the roof pitch is 38 degrees, how large will the living area be on the upper floor? If the roof pitch is 34 degrees, how does it become then? Can anyone do it?

 

[Mats]

the rules can be found at boverket and at skatteverket.