As we know, insulation is based on layers with air gaps. Also concrete absorbs the heat as the heat tries to penetrate the walls.
I have been asked about using insulation in the walls to keep the heat out and the home cooler.
Just like concrete, insulation will slow down the heat from penetration, but as the day progresses, the insulation, like the concrete will absorb the heat. Then as the sun goes down and the off the heat will radiate from the walls.
Also here most roofs are corrugated steel or steel sheets stamped to look like tile. With the sun shining on it all day your attic builds up with heat and heats the attic.
Soffit vents and ridge vents will help a little. Also if you have low open windows on one side of the house, and open windows on the opposite side of the house up higher, natural convection will cause a breeze or airflow through the house. As heat rises it will pull in air from the lower open windows and hotter air will exit through the higher windows.
Another thing you can do is put a cupola on the high point of the roof. A cupola is a structure like a little doghouse. It can be round, square or octagonal in shape. Then you install vents on the sides. With this the heat in the attic will rise into the cupola and the breeze will blow through the vents and clear the heat out.
An expensive way is always to run air conditioning all day, but most of us come here for a cheaper way of life and do not want to spend all our savings on the electric company.