You can have them on residential buildings‽
I live in Europe and I have only seen them in commercial settings to protect store and stuff.
Those metal shutters, that black out the whole room? They have those in Portugal, Spain, most of the mid-southwest Mediterranean. France also. But they’re basically ubiquitous in Portugal. Pretty nifty actually.
Edit: This was driving me nuts, sorry, but I couldn’t find a single good image of what I mean. Here’s the best I could make the robot monkey do (YMMV):
It sounds like you’re describing “Persianas” – a term used in Portugal (and other Spanish or Portuguese-speaking countries) for a specific type of heavy-duty indoor blinds or shutters. These are not the thin metal or fabric blinds but rather thick, often horizontal slats that can be rolled down to cover windows or doors completely, providing excellent light blockage and insulation.
Why? Because they’re amazing.
Funnily enough we call the small thin ones in the picture I posted “Persienner”.
They don’t provide any significant insulation but they can also cover the whole window and block light pretty well. Not perfectly, but good enough for most applications.
If they aren’t enough for you, you can have specific black out curtains that either roll down or slide in front of the window. I suspect black out curtains exist literally everywhere. I am just mentioning it for completeness sake.
I suspect black out curtains are especially common where they get sun 24/7 during the summer.
You can have them where you want. They makes some nice things nowadays.