I worry about permission from the freeholder because it would change the look of the whole side of the building - I don't think everyone else would necessarily want it too, as there are other things about the position, layout, direction, size etc of their flats that make it cooler. And it would need drilling into the bricks etc to install them.
It would be complicated to do though, as there are basically two corner walls and they are mostly glass!! Floor-to-ceiling. There are two places with part of the window that opens outwards, and two doors with handles. So it's like it would need about 8 separate bits of blind, each controlled individually. And then it would still have to fit inside the door handles. And I suspect that would all end up being very very expensive. But I can't find any guideline prices online, so I have no idea really. To make it useful, it would need to be remote controlled, as I don't want it down all day - I work from home and need to be able to see out to some extent (and for various reasons, I also want there to be some visibility from outside to inside!).
Awnings are possible too but as I'm on a main road, ground floor, I worry about vandalism, as lots of drunk pedestrians walking by.
I don't think our management co. would look into it as most people in the building wouldn't need it.
Air con would be great, but my windows aren't the sort to easily vent out of (and I wouldn't feel safe leaving them open at night, on the ground floor), so that means some other solution that involves going through walls and having outside units, which again might be a nightmare for permission. Not to mention expensive to do, to run, and to maintain. But it's worth thinking about. It would be such a relief.