How do I keep my house cool especially my terrace during summer?
Im not sure what building codes or home owner's restrictions there may be but this is a common solution:


There are many types of variations that are tied to houses, stand alone, etc. It is basically a set of posts (or house attachments) with a top plate and vertical boards (pressure treated of course) affixed. This example then has cross bracing so there will be less warping over time. The key is to align the tall boards East to West so that as the sun rises its angled rays do not penetrate to the patio. The height and spacing of the vertical shade boards is based on sun angle mid summer since that is when the sun is highest. Do it right and there should only be sun on the patio when the sun is lower in the sky (winter, spring, fall) as well as possibly early morning and late evening.