We would like to convert our 2nd floor attic. For now, it's only accessible by a folding ladder.
We would like to install a compact staircase in an existing nook on the 1st floor, this will be the only staircase to the 2nd floor in the future.
How do we make the attic count as a living area afterwards – despite the compact staircase?
Check the building code of your respective state to see how "required stairs" are defined. Some states even require a width of 1 meter.
As far as I know, the egress path must include an 80 cm wide staircase. If I understand correctly, this is no longer a compact staircase and will not save space.
It must contain all the characteristics of a living space as defined by building codes. Room height, lighting and ventilation, escape routes. If it is not a living space, it can only be claimed as an additional "bonus" room/hobby room and should not be added to the calculation of living space.