Please do not apply access=private to paths unless they are truly confirmed off-limits to the general public. This tag implies forbidden access under _all_ circumstances and forbids routing. Thank you!

Re helipad roof or not: I admit the semantics are a bit unclear, but if that particular structure doesn't qualify as "a roof", then I couldn't imagine why we do have "building[:part]=roof" at all.

I would say something is a roof IFF it doesn't contain an interior volume, which is the case here.

The fact that there is a helipad (mapped as aeroway=helipad) on that roof is unrelated. It is kind of unique that a building=roof is built solely for the purpose of being walkable, but I think that's the case here.

Re fractional leves: I've seen that done in some other places and it does render correctly on F4Map and Streets.GL iirc. Heights are definitely better, since they are unambiguous, but I don't see anyting wrong with fractional levels. In the code it probably just multiplies that number with some fixed "assumed story height", so it doesn't matter whether it's fractional or not.

Thank you for clarifying on your previous CS. May I still suggest that the structure be indicated "building:part=roof" rather than "=yes" and heights be given in term of building levels - as it is the case with the rest of the building?

Actually, the stories of the building are of different height, so it would be most precise to work with heights here! But I think the whole building should be indicated *either* in terms of eight *or* in terms of levels - mixing the two will inevitably lead to problems. If we have the rest of the building in terms of levels, then so should be the helipad.