During summer, east-facing windows can be a major source of heat gain in the morning, while west-facing windows can be a major source of heat gain in the afternoon. Adjustable external shading devices (such as blinds, awnings, louvres or shutters, or angled metal slats) provide the flexibility to block the low-angled morning and afternoon sun.
While eaves, pergolas and even verandas provide some benefit, they are not very effective at shading east and west windows as they do not block out the lower-angled early morning and late afternoon sun in summer.
Adjustable shading devices allow greater flexibility to make adjustments on a day-to-day or even hour-by-hour basis, in response to changing weather conditions and comfort levels.
If you have a veranda it may be possible to install blinds on the perimeter to shade the windows, walls and veranda itself, making the whole area more comfortable in summer.
Windows that face north-east and north-west are also best shaded by adjustable vertical shading devices such as awnings or blinds.