3. introduction
According to a recent code of bureau of Indian standards, the country may be divided into five major
climatic zones.
• Hot and dry (mean monthly temperature >30 and relatively
humidity <55%).
• Warm and humid (mean monthly temperature >25-30 and
relatively humidity <55-75%).
• Cold and dry (mean monthly temperature <25 and
relatively humidity- all values).
• Composite (this applies, when six months or more do not fall
within any of the other categories).
4. Hot & Dry regions: Ahmedabad, Rajasthan, North Africa, Kutch, Pakistan, etc.
• Orientation and placement, to
minimize sun exposure in
summer.
• Form, compact to reduce
surface areas of heat gain.
• Shade, for maximum sun
protection in summer.
• Allow adequate heat gain in
winter by movable shading
devices.
• Ventilation, for regulation of air
movement
5. outdoor planning
Outdoor spaces:
• As most day-to-day activities take place outside, it is
important to treat the external spaces just as carefully as
the indoors.
• Adjacent buildings, pavements, roads heat up quickly and
cause a glare onto the building during the day and
at night, they radiate the heat stored during the day.
• One way to avoid this is to place walls protecting external
spaces, to keep out dust and winds.
• Also, landscaping like trees, plants and water in enclosed
spaces will cool the air by evaporation.
• But the best solution is courtyards. In these a pool of night
air is retained, as this is heavier than surrounding warm air
• A small courtyard is excellent as a thermal regulator.
Courtyard design with evaporative cooling
6. settlement planning
• Topography, to enhance the efficiency of passive
means
• Orientation, to reduce the sun exposure in
summer.
• Air movement, to provide ample ventilation in
summer and protect from winds in winter.
•
Form, to design compact settlements for mutual
protection
• Hazards, to avoid dangerous sites
Typical settlement for hot-dry regions
7. OVERVIEW OF DESIGN PRINCIPLES..
• Courtyard or Patio
• White Colored walls (“cool” colours reduce heat reflection )
• Arrangement of the houses in is very closely packed to each other.
• Vegetation (reduces the temperature, filter’s the dust in
• and around the house, elevates the humidity level may reduce as well as
increase the wind speed)
• small openings
• double roof or white single roof
• thick walls
• big basin to collect rainwater
• louvered windows
• pergolas
• a water body
8. HOT & DRY CLIMATE
The main points:
• Orientation and placement, to minimize sun exposure in summer.
• Form, compact to reduce surface areas of heat gain.
• Shade, for maximum sun protection in summer.
• Allow adequate heat gain in winter by movable shading devices.
• Ventilation, for regulation of air movement.
Sun orientation
• west orientation is the worst
• The larger building dimension should face north and south
9. Wind orientation
• Main walls and windows should face the wind
direction in order to allow maximum cross-ventilation
of the rooms.
• To reduce the effect of hot dusty winds, the leeward
side of the house is better.
Room arrangement
• 1. Bedrooms-on the east side.
• 2. Living rooms-on the north or south side.
10. Building material
• Sun-dried earth bricks one of the poorest conductors
of heat.
• Traditionally constructed with thick walls and roofs
and with very small openings
walls
• Walls of daytime living areas should be made of heat-
storing materials.
• East and west walls should preferably be shaded.
• Double walls with insulation in between are a suitable
solution.
11. Opening and windows
• 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.
• Windows should be shaded either by shading devices, roof
overhangs or by deciduous trees.
• The size of the windows on the west and east sides should
be minimized in order to reduce heat gains into the house
in the early morning and late afternoon.
12. Roofs
• The flat roof is a good reflector and re-radiates
heat efficiently, especially if it consists of a solid,
white painted material.
• High solid parapet walls along the edge of the roof
can on the one hand provide daytime shade and
privacy.
• The principle involved is to catch an unobstructed breeze at
a high level and channel it to areas in the bottom parts of
the building.
Natural ventilation
13. Passive cooling
• Cooling can be achieved by the evaporation of
water.
• The courtyard is provided with water and plants, it acts as
a cooling source.
• Internal courtyards provides cross ventilation & natural
cooling.
• Most openings are to the internal courtyard rather than
exterior surface.
Courtyard
14. Stack effect
• Outlets at higher levels serve to vent hot air. Ventilators are preferred at higher levels as they help in
throwing out the hot air.
15. Other features
• Colors that absorb less heat should be used to paint the external surface.
• Darker shades should be avoided for surfaces exposed to direct solar radiation.
• The surface of the roof can be of white broken glazed tiles.
• During the day-time openings should be closed and shaded.
• Decreasing the surface of the building exposed to the outside.
• Using materials that take a longer time to heat up.-Providing buffer spaces (lobbies, etc.) between
the living areas and the outside.
16. Elements of Vernacular Architecture
For different Hot-Dry Regions around the world
Main Objective:
the common basic function is to protect the structure from weather conditions
1. Mediterrean House
•Walls made in raw earth bricks, cooked
bricks, stone or tuff. 50 cm - 100 cm thick
walls accordingly to the construction materials.
•Roof characterized by light wood structure,
more often in bricks and lime.
•Closed volumes, few and little windows.
•There isn’t roof projection, but often there are
stairs outside to reach the flat terraced roof.
Region around the Mediterrean sea, like in
Greece, South Italy, Spain & South France
17. 2.Trulli House, South Italy
•the huge massive stone is usually joint to a big basin to collect rainwater used to
decrease of 6-7°C the interior temperature in summer.
•This allows the natural ventilation through the dome holes and is improved by the
white color of the exterior surface made in lime
18. 3. Arabic House
•the climate is so dry, the temperature range is so high, there’s a strong solar radiation and the winds can
transport huge amount of dust and sand.
The architecture design was developed following tradition, culture, religion and climate answers. The features
are:
•building shape
•wall typologies
•interior spaces distribution openings
•ventilation and cooling systems
19. The whole design is focused
around the central square-
shaped patio: an empty
space where all the
rooms face to.
Around the patio often
there are porches on one or
more sides and one or more
stored.
20. 1. NIGHT: the cool air comes down in the court and goes inside each room that face to
it. The flat roof and the thick walls also improve the cooling system.
2. AFTERNOON: the sun directly heat the walls that face to the court. The air heats and
goes up providing for the natural ventilation. The court works as a chimney. The massive
walls and doors protect the interior spaces from the direct solar radiation.
3. EVENING: the air is so hot and the court door heats creating a natural air flow from
the rooms that face to it through the patio. The last cool air goes out from the rooms
in the evening, but also the shadows are longer and quickly the court is protected from
the radiation.
To improve these passive systems they usually fix a wet curtain on the court and a
fountain in the middle.
22. •A circular space enclosed by mud walls is the most typical dwelling
construction in the Kutch district of the Gujarat state & Rajasthan in
India, which has a very high earthquake risk, is called a Bungha.
Materials used
1. Stone
2. wood
3. Bamboo
4. burnt brick masonry either in mud mortar
or in cement mortar.
5. Straw
Characteristics
•consists of a single
cylindrically shaped room.
•has a conical roof supported
by cylindrical walls.
•inner diameter of the Bungha
is between 3m to 10m.
•has only three openings one
door and two small windows.
•construction has existed for several hundred
years.
•This house is quite durable and highly
appropriate for hot & dry conditions.
•The entire construction process, which is
carried out by the mason with very few
unskilled laborers, can be completed within 30
days.
23. •typically found in flat terrain.
•do not share common walls
with adjacent buildings.
(the typical distance from a
neighboring building is 3m)
Gives
protection from
Rain
Solar radiation
Cracks
Earthquake
Wind
circular design and the mesh of mud
plaster and twigs make them resist
any wind pressure and quake.
24. The different spaces (for
men & women-children) are
not interconnected.
A horizontal clay
platform about 50
cm high, is a way to
avoid rainfalls inside
the house
Circular spaces are the main
living zones, rectangular
spaces are for secondary
functions, like cooking cleaning
and storing. They are smaller
and not so strong. They do not
resist very well to earthquakes
or cracks.
25. The thick walls, made of mud, keep the interior cool
when the temperature rises to 40 degrees Celsius in
summer and warm when it beam and posts drops to
10 degrees in winter.
The roof is made of wooden top dome
where bamboo sticks are fixed with a
thick layer of grass put on roof and tied
together.
The walls can not bear the wood beam
of the roof, which runs across the space
diagonally and rests on two wooden
posts. The beam is often kept exposed
outside the circular wall.
26. PLAN
•Due to circular shape of
wall in plan, inertial forces
developed in wall are
resisted through shell
action providing excellent
resistance to lateral forces.
•wall is extended below ground
up to the required foundation
depth, and separate foundation is
not traditionally constructed.
•The construction technique is such
a way that improves seismic
resistance of the inertia force
generated in the roof
27. •a very unique aspect of traditional desert architecture in which the size, location
and orientation of the Bungha are planned for very good structural and functional
results.
The ``modern’’ version had given a go by
to traditional architecture replacing the
twigs of
the `babul’ trees with stones.