The coolest house in the street, you are looking straight at it. Build with coconut-leaves, as well the wall as the roof, it can stand the hottest sun without warming up inside. Often you see very old houses where the wall are flattened with cowdump, the best material to keep insects out, also the blue color is used to keep the flies out. You know, cowdump is the only effective isolation towards soot-seepage and still used to cover the wall of an old teared down chimney.

The concrete houses(floors,roof and brick wall concrete finished) rather build up the heat so that at night it is still as hot inside as during the day.
Personally I don't like these concrete houses as it has no typical Tamil style, except for some details then.
A typical street on the country-side, a village Paalamedu where one of the Jalikattus was held, and the lady in her orange sari you know already as I posted her portrait already from India.

Notice the herbs hanging above doors to protect the house and the colored kolam.