4.2.1  Satisfaction of physiological needs

Human physiology (the functioning of our bodies) is highly dependent on the immediate environment. Our environment should supply the necessary services and facilities for our physiological needs. For example:


Breathing is a physiological process that utilises oxygen for energy production and expels the waste as carbon dioxide (CO2). Housing must allow adequate fresh air to get into the house and used air to get out. This ventilation of air is facilitated by a window. The area of the window surface through which air can pass must be proportional to the floor area of the room in order to get adequate air supply per given time. A guide of 10% (light and air admitting window area divided by floor area) is assumed to be adequate for residential housing.

  • The floor dimensions of a room are 3 m wide and 4 m long. Calculate the size of the window that could supply adequate ventilation.

  • Floor area = 3 × 4 m = 12 m2

    The window should be 10% of the floor area. 10% of 12 m2 is 1.2 m2. The size of the window needed is therefore 1 m wide by 1.2 m height if you had one window, or 0.8 m by 0.8 m each if you had two windows.

Getting clean and fresh air through the window could be compromised by household activities. Interference with breathing due to smoke and gases from the use of fuels such as wood or dung is common. Inefficient combustion releases many toxic chemicals that can affect our skin, eyes and lungs.


This is the ability to observe the immediate environment using our eyes. Naturally, visual physiology requires adequate light in order to effectively see or look at an object. Adequate light is also important for reading, watching TV and attending class lectures in a school. The physical structure of housing provides the required light through two sources: artificial light from electric sources and natural light through the windows from the sun. The minimum recommended light-admitting window area is similar to that for breathing.


Sleep is a time when our body must get complete rest in order to be refreshed for the next day. Sleeping requires a separate room and should be free from any disturbance such as noise and indoor air pollution. The housing structure should provide adequate space in the form of a bedroom that is reasonably free from any environmental hazard that could disrupt sleeping. Separate bedrooms for children and adults are, in many families, a necessity.

Body heat regulation

Housing helps us to regulate our body heat, which means it helps us to keep warm or to keep cool.

  • How does housing help us regulate our body heat?

  • It protects us from the weather, helping us to keep cool by shading us from the heat of the sun, or to keep warm by protecting us from cold, wind and rain.

The exchange of heat between our body and the immediate environment is dependent on the difference of temperature between the two. Relatively cold air is useful to take away excess heat through the process of convection. Convection is involved when there is a heat exchange between our body and relatively cold air moving across the body. Heat loss by conduction is involved when body heat is transferred to a colder surface by direct touch. The third mechanism for heat transfer is radiation, when body heat is lost directly to the immediate environment because of a temperature difference between two objects. Our housing should be suitable to help us regulate our body heat.


Eating food is linked with the digestive system of our physiology. A kitchen for food preparation and a separate space/room where a family gets together for meals are necessary to satisfy our housing needs for eating.

4.2  Basic requirements of healthful housing

4.2.2  Protection against infection