Building Biology is quite a wide subject to cover, but I think the following topics can make us understand the importance of it:
Air movement - The ideal space for air movement must be in every room. Drafts are the reason we experience air movement which also results in local cooling of the body. The rooms should have controlled ventilation (doors, windows, vents, etc) because they require 2-3 air changes per hour. And, if it doesn't happens then we don't feel our 100%. This will gradually and over a period of time causes shortness of breath, crankiness, skin problems, lungs condition and potentially memory loss.
Humidity - The comfortable humidity is 35% to 50%. If the humidity goes below 30% that means the air is very dry. In low humid conditions, the dust particles become more fluid. This sometimes causes static electricity, dry skin & hair, cold and respiratory illness. So, in this case our country India (major parts) is quite lucky to have balanced amount of humidity in air. However for the "less privileged" places (humidity wise ha ha) which are extremely cold should use controlled humidifiers.
Electrosmog - It is the accumulation of Electromagnetic Influences in one area of a household which is definitely not possible through one electronic device. It has to be stronger sources of radiations such as Wifi routers, Smartphones, wireless technologies (bluetooth etc). This may cause many problems like weak immune response, allergies, chronic inflammations, reproductive dysfunction and other medical conditions.
So, to have tight and healthy sleep keep your phone out of your bedroom and switch off the wifi router before sleeping....
A suggestion to all who are not able to be their 100%, just have a look around and see what's missing from the above points and try to make a change in your own lives to see the benefits of Natural Needs of human body.....stay healthy! See my website for my designs and finished projects.