Even during the coldest of winter months, some houses are warm and comfortable while others are cold, dry and dusty! How is it possible?

Houses that are planned and built, taking into consideration the local climate will be warm and comfortable in cold weather!

Climate friendly
One of the basic requirements of any shelter is to keep us insulated from the extremes of weather conditions. The directions of the prevailing winter winds play a major role in conditioning the micro climate inside our houses. Suitable precautions should be taken to incorporate safeguards against cold while planning our houses. Even deaths due to cold wave conditions are common in many parts of India.

Artificial v/s natural
We can always keep our houses warm by using an electric heater or gas burner, but apart from being costly, they also reduce the relative humidity inside our houses. The resulting hot and dry air is not very healthy in the long run for the respiratory system. Natural methods of keeping warm in winter do not reduce relative humidity but in fact, increase it.

During winter we get very cold, dry and dusty winds from the north and east. This is the result of northeast monsoon winds, which blow mostly over lands that are dry and bring with them much dryness and dust. If we allow these cold winds to enter from the northeast, then the entire house will lose all its warmth and will be as chilling and ‘bone dry’ inside as it is on the outside. This applies to most parts of India, except the coastal region and few other places.

Cold, dry and dusty weather is bad especially for the old, sick and the little ones. Since we spend most our time indoors, our home is expected to keep us warm and comfortable during this season.

Effect of cold winds: Our respiratory system dries up; coughs and asthma attacks are also common during this season due to the low humidity coupled with cold weather. Our skins crack and lips flake off, when the relative humidity is very low.

Positioning of windows: Though we cannot live without fresh air, it is better to avoid big windows on the windward side, ie, east and north! Otherwise, lots of cold, dry and dusty winds will enter our houses and there may not be much difference between inside and outside. We should position windows in such a way that we get fresh air without suffering from cold drafts of air. Keep small windows on east and north. We can compensate this by having bigger windows in the south and west. (Diagram 1). We have to be very careful in positioning windows to conserve heat — every calorie counts in fighting cold.

It is advantageous to keep big windows on the leeward side, ie, in the south and west. Foul air from inside the house will be sucked out from the windows in the southwest due to the low air pressure in these directions.
Apart from this, passive ventilation by diffusion air exchanges will also take place when there is no air suction — this will allow fresh air inside our houses without suffering heat loss. (Diagram 2)

Things remain fresh during this season and as we don’t sweat much; frequent air changes are not needed during winter. Though of course, it is a necessity during hot humid weather.

For natural lighting
Big windows in the north and east are a major source of heat loss. We can plan windows in such a way that we get sufficient natural lighting during the daylight hours, without loss of heat. Keep minimum window areas, just sufficient for natural lighting, in these directions. These can be kept closed during winter months. Window shutters with double glazing will also help in reducing loss of heat.

External door positions: We can avoid keeping external doors in the east and north since each time they are opened, gusts of cold, dry and dusty winds will enter the house causing much heat and humidity loss. It is advantageous to keep doors opening to the outside on the west or south.

Planning for weather friendly houses in India means avoiding winter monsoon winds and welcoming summer winds. Understanding the weather conditions and incorporating suitable measures in planning will result in  eco-friendly houses which are warm, healthy and comfortable — the natural way.

The author is an architect and can be contacted on mobile no 9844132826 or e mail: architectjayaram@yahoo.co.in