Architecture in cold climate

architecture in cold climate, vernacular architecture style of India in cold climate. things to be consider while designing a house in cold climate.

1. CLIMATOLOGY PRESENTATION ON COLD CLIMATE BY: VIKESH KULMANI SARTHAK PRATEEK ROHAN HARSH

2. INTRODUCTION Regions that lies on the cold climate zone are situated at high altitude. State such as a Jammu and Kashmir, Himachal Pradesh, Uttarakhand, Arunachala Pradesh, Sikkim and northern part of UP have a cold climate. The temperature ranges between 20 – 30 C in summers, while in winter ranges from -3 – 8 C, making it quite chilly. The cold climate can be further divided two categories: Cold and sunny Cold and cloudy

3. COLD AND SUNNY The cold and sunny type of climate is experienced in Leh (Ladakh). The region is mountainous, has little vegetation, and is considered to be a cold desert. The solar radiation is generally intense with a very low percentage of diffuse radiation. In summer, the temperature reaches 17 – 24 C during the day and 4 – 11 C at night. Otacamund , Shimla, Shillong , Srinagar and Mahabaleshwar are examples of places belonging to this climatic zone. These are generally highland regions having abundant vegetation in summer. The intensity of solar radiation is low in winter with a high percentage of diffuse radiation. In summer, the maximum ambient temperatures is in the range of 20 – 30 C during the day and 17 – 27 C at night, making summers quite pleasant. COLD AND CLOUDY

4. In winter, the values range from -7 to 8 o C during the day and -14 to 0 o C at night. Winters thus, are extremely cold. The relative humidity is consistently low ranging from about 10 – 50 % and precipitation is generally less than 200 mm per year.  The sky is fairly clear throughout the year with a cloud cover of less than 50%.  In winter, the values range between 4 and 8 o C during the day and -3 to 4 o C at night, making it quite chilly. The relative humidity is generally high and ranges from 70 – 80 %. Annual total precipitation is about 1000 mm and is disturbed evenly throughout the year. The sky is overcast for most part of the year except during the brief summer. The main criteria for design in the both climate region aim at resisting heat loss by insulation and infiltration, and promoting heat gain by directly admitting and trapping solar radiation within the living space.

5. ESSENTIAL FEATURE IN DESIGNING OF A HOUSE Building will have sloping roof. Windows will have wooden panels. Timber paneled wall be used instead of brick and stone masonry. Bedroom will be on south west of the house. Kitchen will be on south east of the house. Dining will be on the south. Bathroom will be on the north west of the house. Natural light is important in the house. Flooring of the house must of the timber. Living area should be in the north of the building. Utility room shoulf be in the south. Cross ventilation is very important forhealthy living. Trees can be planted near windows for block of cold air. DESIGN CRITERIA Increase thermal resisitence Increase thermal capacity Increase buffer space Decrease air exchange rate Roof insulation and double glazing Thicker walls Air locks/lobbies Reduce shading Utilize heat from appliances Trapping heat Orientation and shape of building Use of trees as a wind barrier

6. RECOMMENDATIONS GENERAL RECOMMENDATIONS FOR A REGIONS WITH A COLD AND SUNNY OR COLD AND CLOUDY CLIMATE ARE AS FOLLOWS: LANDFORM - building should be located on south slope of a hill or hill for better access to solar radiation. OPEN SPACES AND BUILT FORM –Buildings should be clustered together to minimize exposure to cold winds. open spaces such that they allow maximum south sun, they should be treated with a hard and reflective surface so that they reflect solar radiation on to each other

7. STREET WIDTH AND ORIENTATION : In cold climates street orientation should be east to west to allow for maximum south sun to enter the building. the street should be wide enough to ensure that building on one side do not shade those on the other side. ORIENTATION AND PLANFORM: Building must be compact with small surface to volume ratios to reduce heat loss. Windows should face south facilitate direct gain. The north side of the building should be well insulated. Living area can be located on southern side while utility area such as stores can be on northern side. Air lock lobbies at the entrance and exit points of the building reduce heat loss. Heat generated appliances in rooms such as kitchen may be used to heat other parts of building.

8. BUILDING ENVELOPE ROOF: False ceiling with internal insulation such as a polyurethane foam, thermocol , wood wool etc. are feasible for houses in cold climates. Aluminum foil is generally used between the insulation layer and the roof to reduce heat loss to the exterior. A sufficiently sloping roof enables quick drainage of rain water and snow. A solar air collector can be incorporated on the south facing slope of the roof and hot air from it can be used for space heating purposes. Skylights on the roofs admit heat as well as light in winters. WALLS: walls should be made of materials that lost heat slowly. The south facing wall (exposed to solar radiation) could be of high thermal capacity (such as a Trombe wall) to store day time heat for later used. The wall should also be insulated.

9. TROMBE WALL A Trombe wall is a system for indirect solar heat gain and, although not extremely common, is a good example of thermal mass, solar gain, and glazing properties used together to achieve human comfort goal passively. It consists of a dark colored wall of a high thermal mass facing the sun, with glazing spaced in front to leave a small air space. The glazing traps solar radiation like a small green house. A successful Trombe wall optimizes heat gain and minimizes heat loss during cold times, and avoid excess heat gain in hot times.

10. Hollow and light weight concrete blocks are also suitable. FENESTRATION Its advisable to have the maximum window area on the southern side of the building to facilitate direct heat gain. They should be sealed and preferably double glazed to avoid heat losses during winter nights. condensation in the air space between the panes should be prevented, Movable shades should be provided to prevent overheating in summers. COLOR AND TEXTURE The external surface of the wall should be dark in color so that day absorb heat from the Sun.

11. LADAKH Ladakh is a region in the Indian state of Jammu and Kashmir that currently extends from the Siachen Glacier in the Karakoram range to the main Great Himalayas to the south, inhabited by people of Indo-Aryan and Tibetan descent. Ladakh is the region at the higher altitude (3505 meters from sea level) During the extreme winters, from November to March, there can be a minimum temperature of about -40 degrees. The rainfall in this region is as low as 10 cm annually. This is because it lies in the rain shadow of the Himalayas However, summers are quite warm with temperature around 30 degrees, and clear skies.  Mountainous region There are scanty patches of grasses and shrubs for animals to graze. During the summers, trees of fruits such as apples, apricots, and walnuts bloom. Fauna like Yaks, ibex, Tibetan hare, Blue sheep, wild ass, Bharal , Marmot, the Tibetan antelope, also called the Chiru and the Snow Leopard etc. Cold desert Climate cold and sunny Regions- kargil , leh , nubra , Zanskar .

12. SETTLEMENT PATTERN Leah is the biggest town of Ladakh. The settlement of various sizes are located along the meandering river Indus flowing from east to west. This creates northern settlements facing south to allow maximum sunlight. The houses located on the slopes of the mountain rather than plains or valley I order to increase the duration of sun. Also they are close to water bodies and fertile land. Urban planning Leh is typically located on the northern banks of the Indus river. The old town is on southern slopes of mountains where as newer parts are extended plains south west direction. The highest point of leh is occupies by houses of nobles and lower side by commoners and main bazaar area. The vertical staging of building ensures the sunlight to all individual houses. The houses are placed in such a manner so that its 2-3 sides are shared with other house to reduce heat loss. The street pattern of old town such that its allow maximum solar penetration. The important streets are laid in north south axis.

13. ARCHITECTURE SPATIAL LAYOUT Most of the houses two storey building Larger are based on courtyard while smaller houses don’t have the courtyard The ground floor is low in height, used in keeping livestock, storage purposes, and also to collect toilet waste.

14. Upper floor is usually used for living purposes usually consist of prayer room, toilets, kitchen and drawing rooms. Sometimes kitchen and sleeping area same to add warmth inside the house. Main hall is furnished with carpets and smoke chimney. The main living room is fitted with large windows facing the sun it traps solar radiation as and indigenous green house mechanism without pening the window in some cases these windows provided with double glazing to insulating properties.

15. MATERIAL AND CONSTRUCTION Primary building material is earth and timber available locally. Both are natural materials offering climatic comfort in condition of Ladakh. They are used due to their high thermal insulting properties. Mud plaster is applied on walls. Quartzite stone is used in making lower storey places or forts where protection from water is required. Stones are used in lower parts of wall to provide protection and strength. Sun dried earth blocks 300 x 150 x 150mm used for walls of thickness 300 or 450mm. Soil available is alluvial soil found in bank of river.

16. Floors of lower storey made up of mud and upper storey by timber. Its observed that traditional construction of earth block and timber was able to offer temperature difference of 40 C in extreme winters. When outside is -20C inside its 20C recorded. The sills and jambs articulated by the plaster band often colored in black or red these timbers lintels and plaster bands are the distinct feature of ladakhi architecture.

17. ROOF – FLAT ROOF Beams are placed 50-60cm apart having 15cm diameter and 3-4m long. These beams are covered by popular willows spread in the other direction its thickness is 20-30mm 15-20cm of dry grass, Hay etc. over the willows, finally plastered of clay mud

18. Capital and post supporting the roof This type of wooden design is specialty of Ladakh. The lintels of doors and windows are corbelled features with ornamentation. Doors and windows are made of timber brought from Kashmir.

19. KOTI BANAL ARCHITECTURE STYLE In the rajgarhi area of Uttarkashi district of Uttarakhand, India a large number of intact buildings of a distinct earthquake resistant type known as koti banal can be found, this construction type has been practice for more than 200 years and its reported that koti banal architecture withstood and performed well during many past damaging earth quakes in the region.

20. SITTING AND ORIENTATION Situated in a firm ridge on a plane ground having rock outcrop without any buildings in the immediate vicinity. THERMAL STRATEGY High thermal mass of the budding envelope retains heat. Small window opening prevent heat loss and are south facing. Low floor height (2.2-2.5m) reduces the internal volume of air to be heated. The attic space act as a thermal buffer. Regular plain and elevation shapes, integration of wood beam over the total height of building. Small opening size and arrangement of shear walls. Walls are strengthened against out of plane failure by shear key in the form of a wooden member which runs vertically through the storey and is structurally connected to the timber framing of the building.

21. For lateral load resistance (horizontal), pair of wooden logs connected to each other wooden shear pins/tenons from a wooden frame which is braced by well dressed flat stone masonry. The dry stone masonry between the logs enables a certain levels of flexibility and allows lateral deflections of the building without damage effects.

22. BUILDING FEATURES ROOFING SYSTEM Typically, roofing span is half of the building width. The roof constructed consist of a wooden frame which is expected to act as a flexible diaphragm and is clad with slate tiles. WALL SYSTEM 50-60cm thick timber reinforced stone masonry. The thickness of wall is a determined by the thickness of the two parallel arranged wooden logs. FLOOR Wooden beams door and planks resting on wooden joists supported by beams or walls. DOOR AND WINDOWS A single small door access on the ground floor and relatively small south facing windows floor above with wooden frames and shutters. SEMI OUTDOOR SPACES The upper two floor is have balconies running around the whole building cantilevering from the wooden logs of the flooring system with a wooden railing.

23. ATTIC SPACE MULTI FUNCTIONAL SPACE SERVED AS ABODE OF GOD STORAGE OF GRAIN WINDOWS- VENTILATES AND HELPS TO DRY THE GRAIN PROTECT FROM THE RAIN INSULATES THE HOUSE

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