You've met the typical design of modern railroad buildings in Germany. There were several loco sheds and repair shops of that style built in the last years. So you can use it for eras V and VI.
Because a declining number of depots and repair plants is responsible for a roughly constant number of locos, most of these buildings are larger. Modern loco sheds with only two tracks are rather rare. But on the other hand, they're optimal for the limited space on model railroad layouts.
But to me it looks kind of overcrowded.
So for instance one ladder would be enough. If two ladders are installed, it will usually be a clearly larger building with many times that roof area. Additionally the ladders look oversized. And the safety guard of ladders like these ones usually start at a height of about 3 meters or so.
And on a German roof you will usually only find roof vents (and chimneys on older buildings) but no air conditioning equipment. It will usually be installed inside the building—preferably on floor level for easier maintenance. Additionally I've never heard of a locomotive shed or repair shop with air conditioning (at least in Germany).
But the general impression of your building is quite good!
By the way:
Omiting catenary inside buildings is common practice in Germany, too—especially in buildings which are accessible via turntables or "Schiebebühnen" (what's the English term for those platforms with track which move sideways?).
But in these cases, the space for a raised pantograph won't be needed. If no catenary is planed to be installed inside the building, the builder will
save money by installing lower doors. So there will hardly be an excuse for omiting the catenary in that building—especially considering the mountings for the catenary's carrying ropes above the doors (or are these cubes intended to be something else?).