Emergency lighting is cheap, no need whatsoever to haggle. Some councils/fire departments are more strict than others but on the scope of things it does not matter, the extra cost is negligble, provide loads, keep the coucil/fire dept happy.
Always: No natural light. Change of direction, exit stairs, change of floor level, toilets, exit doors...and rule of thumb, 1 per 10/2 metre in public areas. It really is common sense, the cost is ziltch. £20 quid per fitting and that's all.
I always state, guranteed emergency lighting will be passed, thus the client has no extra concerns. (some architects don't always realise, if using fancy fittings and the 'ugly' factor comes in, that their design will be not as plan...hey, I can convert any fitting to work in emergency mode, no problem but it costs. Most times if fancy stuff is used a compromise is met...but not always. I luv fancy stuff, that is where the money is at