Trees should be planted on which side to protect buildings from heat gain

Dear Shruthy, I manage 2 floors, terrace planting front yard and back yard gardeining. So I have few observations. Now Indian houses are typically built based on Vastu. And mostly people prefer houses that are either East facing or North East facing. The reason being Sun rises in the East and people want the Sunrays to penetrate their houses. The same is with North East. So it makes sense not to plant trees in these areas because you are blocking the sunrays from entering the premises. The remaining options are West and South west. Sun sets in the west and so you cany miss out on those rays in the evening and this rules out even planting in the West. The only logical place is the South of the building because all through the day, there is enough sunlight for the plants. For effective Photosynthesis, effective day light is important. Because the sunlight is always to the Souyh, makes sense planting trees to the South of the house.