2. MAJOR CLIMATIC ZONES IN INDIA
According to a recent code of bureau of Indian standards, the country may be
divided into five major climatic zones.
Zone Mean
Monthly
Temp. (°C)
Mean
Monthly
R.H. (%)
Mean
Monthly
Precipitation
(c.m.)
Hot & Dry >30 <55 <5
Hot &
Humid
>25-30 <55-75 >5
Cold <20 55 5
Moderate 25-30 <75 <5
Composit
e
It has a very hot and dry summer,
followed by a humid season with
monsoon rains.
3. HOT AND DRY REGION
Places like Rajasthan, Ahmadabad, Gujarat comes under this region.
An important characteristic is a high temperature variation, Very high temperature during
day and cold at night.
BUILDING FORM AND ORIENTATION.
Orientation and placement to minimize sun exposure.
Compact form to reduce surface areas of heat gain.
Courtyard or Patio with vegetation for natural
ventilation, and small water body for humidity control.
Small openings in thick white coloured exterior walls.
Double roof or white coloured single roof.
4. HOT AND DRY REGION
BUILDING MATERIALS AND OPENINGS.
Sun-dried earth bricks one of the poorest conductors of heat.
Openings and windows are necessary for natural lighting and ventilation. More windows should be
provided in the north facade of the building as compared to the east, west and south as it receives
lesser radiation throughout the year.
The exterior thick walls of brick, stone to store heat
energy in daytime and radiate at cold night.
Hot air from interior went out by stack effect
complemented by the arrangement and size of openings.
Using materials that take a longer time to heat up.
Providing buffer spaces (lobbies, etc.) between the living
areas and the outside.
5. HOT AND DRY REGION
The most common method is to have wide outer walls, to keep it
cool, as
well as warm during nights. But the main reason for thick walls is
ease in
construction and cheap availability of stone in nearby quarries.
But traditionally people use cow dung as a paste on the outer walls,
which creates an insulating layer and also repels insects.
The roof of this small hut also plays a significant role in heat
regulation, as it receives direct heat form sun, it is usually kept
conical to facilitate air ventilation, with two to three layer of grass,
making it thick, sometimes even water can be sprinkled over it.
6. HOT AND HUMID
Costal areas in south India and hilly areas in north east comes under this region. Major
cities having this climate are Goa, Mumbai, Visakhapatnam, Kolkata, Chennai etc.
High humidity, strong sun, glare from the sky and horizon characterize this climate. There
are long monsoon periods with heavy rain. But the breezes, especially in coastal areas,
can alleviate discomfort considerably.
Requirements in a hot and humid climate:
Minimization of high day temperature.
Avoidance of direct exposure of building surfaces to sun.
Humidity control.
Continuous air circulation to reduce heat.
To create a temperature difference between indoor and outdoor .
7. HOT AND HUMID
Orientation and ventilation:
Semi – open spaces for light and air movement .
Buildings should be spread out with large open spaces in between for uninterrupted air
movement.
Cross ventilation is very important. large openings to unobstruct
air path and to ensure proper ventilation.
The openings should be shaded by external overhangs. Outlets
at higher levels to vent hot air.
Proper water proofing and quick drainage of water is essential
due to heavy Rainfall.
8. HOT AND HUMID
Shading:
Keep sunlight off of building walls: After aiming the building to catch the breeze, try to face the long
sides (with most of the windows) towards the south and north so the roof overhang shades walls
and windows in the middle of the day.
Shade in the afternoon: Keep west and east sides short to let less of the hot, low angle morning
and afternoon sun heat up walls, especially during the hottest season. Be sure you are considering
whether the sun is in the northern or southern sky at this time of year.
Cover openings on west and east ends. Use few windows and
doors. For openings use vertical sunscreens, climbing vines,
or shrubs to reduce heat gain on western walls.
9. HOT AND HUMID
Building materials:
The locally available materials which dominate building construction in these climatic zones are;
Timber
Sun dried and kiln burn brick
Thatch and Bamboo
Clay tiles for roofing
Cavity wall detail
Above: typical thatch
roof.
Left: half round country
clay tiles.
10. HOT AND HUMID
extensive use of bamboo in building construction.
Timber used as vertical and horizontal support.
11. COLD AND DRY REGION
Regions that lie in the cold climate zone are situated at high altitudes.
Places like Leh, Ladhak, Srinagar comes under this region.
Essential feature in the designing of house
-Building will have sloping roof.
-Windows will have wooden panel.
-Timber paneled wall will be used instead of brick or stone masonry.
-Thick wall will be used with sound insulation.
-Bedroom will be on south west of the building.
-Kitchen will be on south east of the house.
-Dinning will be on the south.
-Bathroom will be on the north west of the house.
Mass of houses in Ladakh.
12. COLD AND DRY REGION
-Natural light is important in the house.
-Flooring of the house must be of timber .
-Noisy place is avoided for building.
-Living area should be in the north of the building.
-Utility rooms [washing and domestic works] should be in the south.
-Cross ventilation is very important for healthy living.
-Trees can be planted near windows to block cold air.
Roofing in cold and dry region:
- Gable roofs are used in hilly areas, as these roof types are able
to shed snow in hilly areas.
- The main used material for roofing in hilly areas is timber, as it is
locally available from trees.
- Trees which are used for this purpose are: cedar.
13. COLD AND DRY REGION
Building methodology in cold regions
In hilly parts where rocky rubble, ashlars and pieces of stone are available.
These can be patched together with a mud mortar to form walls.
Finer stonework veneer covers the outside.
Sometimes wood beams and rafters are used with slate tiles for roofing if available.
These houses usually have two stories, with the livestock living on the ground.
Often a verandah runs along the side of the house.
The roof is pitched to deal with the monsoon season and the house may sit on raised plinths or bamboo
poles to cope with floors.
14. MODERATE CLIMATE
The temperate climate has mild to warm summers and cool winters.
The need for winter home heating is greater than the need for summer cooling.
It is a relatively comfortable climate, especially near
the coast, where summers are cooler and winters
warmer than further inland.
In the mountains of the Great Dividing Range, winters
are cold and summers are pleasantly mild.
Few opening on external side other than door.
Cooking and sleeping outdoor in summer were as
inside in winter.
Moderate zone - BANGALORE
15. MODERATE CLIMATE
Building material used:
Floor : Lime concrete
Walls: Stone masonry with
lime mortar
Roof: Stone slabs with
lime concrete screed
cover for flat roof.
Mangalore tiles for sloping roof.
Passive features.
Reduction of solar heat gain:
-by orientation of the bedrooms towards north
By shading of east and west walls by neighboring buildings.
- By shading the windows and walls with projecting stone slabs
Reduction of internal heat gain:
- By placing the kitchen outdoors in summer(and indoor in winter)
Reduction of heat transfer to interior
- by insulating roof.
Increase of heat loss
- by ventilation and smoke outlet through chimney.
16. COMPOSITE CLIMATE
The composite zone covers the central part of India.
Cities like Allahabad, Kanpur, new Delhi experience this climate.
A variable landscape and seasonal vegetation characterize this zone.
The primary element was a single interior living space, which may have been sub- divided, multiplied, or
otherwise modified.
Second, an external space adjacent to or surrounded by the dwelling was emphasized by use of
elements such as low platforms or verandahs.
An average hut measured approximately 5 to 6 meters long and 3 to 4 meters wide
These huts were arranged in a linear pattern along the main street of a village, usually amidst a group
of bamboo trees.
Composite zone - JHARKHAND......
17. COMPOSITE CLIMATE
The primary element was a single interior living space, which
may have been sub- divided, multiplied, or otherwise
modified.
Second, an external space adjacent to or surrounded by the
dwelling was emphasized by use of elements such as low
platforms or verandahs.
An average hut measured approximately 5 to 6 meters long
and 3 to 4 meters wide.
These huts were arranged in a linear pattern along the main
street of a village, usually amidst a group of bamboo trees.
The houses were normally surrounded by a fence made of
bamboo, shrubs, or twigs that defined the boundary between
the public street and the semi-public courtyard area in front
and at the rear of the hut.
This open-to-sky courtyard acted a prime space for the
house, especially during the day in winter and in the
evenings in summer.
Most day to day activities occurred in this space. Often there
was a well in this courtyard that served as the source for
water for drinking, bathing, washing, and cooking.
People used this courtyard to dry clothes, crops, and
eatables during the day time.
The house sat on a raised platform made of compacted
earth.
The high thermal mass helped keep the house cool in the
evenings in summer which made it pleasant for people to
18. COMPOSITE CLIMATE
The huts normally had minimal fenestration. Often, the only opening on the external walls was the main
door. Some houses had windows, but they were small and placed high to ventilate the indoors while, at
the same time, acting as a visual barrier for the private spaces. The small windows also served to keep
the hot summer sun and cold winter winds out.
The roof rested on nine wooden posts erected in
three rows, with three posts per row. These posts
were sunk into the raised platform and tied with
wooden beams and purlins that supported the roof
structure. The huts usually had a gabled thatch roof.
Bamboo sticks formed the mullions to support the
thatch.
Mud wall with wooden
posts of typical hut
Special mud blocks left with
vegetable waste matter to
mature for wall
The thick thatch used as roofing material
prevented rain from entering
the house and at the same time provided
insulation to the building
19. COMPOSITE CLIMATE
PASSIVE FEATURES:
Summers:
Use evaporative cooling.
Protect against summer heat gain.
Keep the sun out in summers to reduce heat gain and
glare.
Flatten day-to-night temperature swings to reduce cooling
in summers.
Use vegetative cover to prevent reflected radiation and
glare.
Expand use of outdoor spaces during the night.
Night time flush ventilation to cool thermal mass.
Winter:
Let the winter sun in to reduce heating needs.
Protect from cool winter winds to reduce heating.
Expand use of outdoor spaces during the day.
Spring:
Use natural ventilation to cool in spring.
In part, the specific climate of Jharkhand has given rise to
particular vernacular types.