A south facing flat is what everyone says they want until they try to work in one at two in the afternoon.
The listing called it bright and airy and it is. It is also unusable for about four hours a day in summer, the sofa fabric is fading on one side, and you cannot see a laptop screen from the good chair. The natural response is to close everything, which converts a bright flat into a dim one and wastes the only reason you paid extra for it.
Glare is a contrast problem, not a brightness problem
This is the part that changes what you buy. Your eyes are not struggling because the room is bright. They are struggling because one part of it is very bright and the rest is not.
A window at full sun next to a shaded wall creates a contrast range your pupils cannot resolve, so everything away from the window reads as gloom. Blocking the window entirely does fix the contrast, by making the whole room dim. Diffusing it fixes the contrast by bringing the window closer to the rest of the room, and you keep the light.
Which means the useful product is one that scatters daylight rather than one that stops it.
The adjustable middle
Sheers do this well and give you nothing after dark. Blackout does the opposite. What a south facing room actually needs is a blind you can move between the two as the sun goes round.
That is what makes a banded fabric worth considering here. Alternating sheer and solid stripes on a doubled roll let you set the ratio rather than pick a side, and it takes about a second to change. Have a look at 1clickblinds.co.uk/collections/day-and-night-blinds and you will see the mechanism: at midday you offset the bands to knock the intensity back, at seven you line them up and the room stays open, and once it is dark you close them.
In a one aspect flat, where every room faces the same way, that adjustability is doing a lot of work.
What to do about the fading
Worth mentioning because it is the cost nobody prices in. Direct sun degrades fabric, timber finishes and printed material, and it does it on a schedule you can predict from where the sun lands.
You do not need to block the window to slow it. Reducing direct exposure during the worst hours makes a difference, and so does simply not putting the good sofa in the brightest position. Rotate rugs and cushions occasionally. It is unglamorous advice and it works.
The rooms that still want something else
A bedroom in a south facing flat has the opposite requirement, and it is the room where people most often buy the wrong thing because they bought everything at once. Sleep wants opacity, so specify from the blackout blinds for the bedroom selection there and keep the adjustable fabric for the living space.
A kitchen or a bathroom, where the window gets steam and the fabric gets touched, is usually better served by a wipe clean surface. Something from the roller blinds made to measure selection in a suitable finish will outlast a fabric that was chosen for how it filters light.
Do not fix it by giving up the light
The failure mode with a bright flat is closing everything permanently and then complaining that the place is dark. It happens constantly, usually within a year of moving in.
Handle the glare where it occurs, in the middle of the day, with something you can move back afterwards. The brightness is the asset. The four bad hours are the thing to manage.
