Can’t speak for others, but you’d need permission to access the roof of my building – not that it’s a particularly interesting one anyway.

R.

Try the top of the Cathedral, the 5th floor terrace at quai du Seujet, the top floor of the FER, ask the Société de lecture if they would let you go to the library...

The Manor restaurant terrace?  It is on the top floor, so almost a roof

Hotel Bel Esperance, off Rue Verdaine in the Old Town, has a rooftop view that almost rivals that of Cathedral de St. Pierre.

Hmmmm, do I need a permission from Regie I suppose? Because rooftop of normal building would be ideal for me :)

In my opinion if you have a roof with normal access eg roof garden you just need the agreement of one of the tenants owners but if normal access is not permitted I would first speak to the concierge to get hios opinion and then the regie and you would have to submit detailed info number of people, weight of equipment etc. and I think it very unlikely you would get permission.  

So choose your roof first and then start discussing whether access wil be allowed

Very unlikely? Heh, strange... what's wrong to be at roof probably 2-3 hours?

It is question of health and safety and insurance.  Many years ago (36 to be exact) I gained access to the roof of the tower block where I lived and abseiled off it.  It was filmed on TV. 

It was a council owned block in Blackburn, England,  and my stunt was televised.  I decided to ring the council and warn them that it was going to be shown on the local news and immediately they told me I could not have permission to do that.  I calmly informed them that it was a little late as the event had taken place that morning.  I heard no more but could have been evicted.

And that was in the days before health and safety, insurance etc came into force.

So you could take the risk and do it without permission but the consequences could be unpleasant.  Depends how much of a risk taker you are.

Still what I said before was just expressing an opinion 

'... I'm searching for nice roofs in town for photoset...'

Onis, does it have to be A roof top?

or ANY high place without background?

Other than the nice and helpful suggestions above, may I include:

Top of the Salève. It is very accessible and would give you beautiful views!

there is roof access at the Hotel Metropole, its a great view

Apart from personal safely, insurance and public security issues, you’re likely to be questioned very closely as to your intent and purpose.  After all, if the owners and/or tenants of a building are denied access to the roof, the chances of a ‘visitor’ will be even fewer.  Your photographs could provide valuable input for burglars, arsonists, heaven knows who.

This isn’t a particularly Swiss practice.  Similar strict regulations were certainly in force when I lived in a top-storey flat in Westminster in London.

Yes, Saleve is very nice, but I need roof :-)

probably will stay with hotels terrace ;)