Large windows vs small windows:
A large window is a curse in the hot climate of Pakistan. The larger the window more light (HEAT HEAT HEAT) it allows to accumulate in the room, resulting in exuberant electricity bills because of air conditioning. I have minutely observed building constructed during the British Raj in the sub continent. All of them have small windows. They allow less heat and light in the room.
No exhaust fans:
All the hot air in the room rises and collects near the ceiling. Exhaust can suck this air out of your room, helping your air conditioner to do little work. Ever wished your house to be as cool as the air outside post-rain, install an exhaust. It will blow the hot air out and suck in the cool air.
No clearstory (roshan daan):
Clear story is a natural cost effective way of removing hot air from your house. The clearstory (roshan daan) vanished from the Pakistani architecture long ago for unknown reasons. One reason was difficulty in shutting them before the rain or dust storm. They were a must in buildings constructed during the Raj, but now they are seen permanently shut down or inoperative in the few surviving buildings of the Raj. A roshun daan regulates the light and ventilation in the room. It has combined features of a clear story and sky light. In summer it is kept open to ventilate hot air and in winter it is shutdown and acts as sky light.
Sky lights are large glass-covered holes in the roof, which allow plenty of sun light in the room during the day. They were also a basic feature in old buildings in the Subcontinent. The brown sahibs are so fond of renovating their offices that they covered the magnificent sky lights with plaster of Paris false ceiling and artificial lighting. Now they spend thousands on UPS and generators.
A bamboo blind (chiq) installed outside the window stops the light (heat) from entering in the room. Its more effective and cheaper than curtains. The curtain tries to confine the heat and light between the glass pane and itself. Most of the heat still manages to leak in the room.