I am currently doing a lighting renovation design for senior residence facility. The facility has a single generator (emergency) with one ATS that serves the entire bldg with emergency and non-emergency loads. Currently all of the existing light fixtures thru-out the bldg do not have battery backups, there are no UPS equipment or self contained wall packs. all of the lighting is connected to the generator thru one ATS.

Is this in violation of the NEC 7006(d) - Use of transfer equipment?
I recommended for the owner, to avoid installing an additional ATS and gear, to install light fixtures with battery backup or wall packs for areas being renovated.

does NEC 7005 allow this system with a single ATS?

thanks in advance

I think you'll find the NEC to be less than helpful on this point. It all comes down to what type of system you have. Not in the technical sense, but in the administrative sense.

That is, is your system 'required,' 'emergency,' or 'optional?' Only the AHJ and the architect know for sure.

and that is so true. I guess the system we have is emergency but even it was classified as 'required' I still requires a ATS for emergency circuits?

Though more than one hat can be thrown into the ring...

It is usually the case that the Fire Marshall is the AHJ.