High Altitudes create very cold climate experiences in these regions.
The temperature ranges between 20 - 30°C in summers, conversely in winters ranges from -3°C to -8°C.
Site analysis is highly required to find the balance and to design the climate-responsive building.
Physiological Objectives
Exposure to cold winds should also be minimized. The main objectives of building design in these zones are resisting heat loss and promote heat gain.
To resist heat loss, the designers should consider decreasing the exposed surface area of the building. To create buffer spaces between the living area and the outside. Along, Decreasing the rate of ventilation inside the building.
Promoting heat gain by avoiding excessive shading, since solar gains would be beneficial. Also, utilising the heat from appliances.
Design Objective
Capturing the solar heat as much as possible is important but at the same time, insulation is equally important.
A building needs to be insulated properly to retain the internal heat with minimum loss to the environment.
Form and Planning
The south slope of a hill or mountain is ideal locations for buildings for better access to solar radiation.
Locating the building on the leeward side would help reduce exposure to the harsh cold winds.
Unfortunately, if the southern side of the building is windward, then proper glazing would keep the cold wind from entering the building.
Natural wind barriers are helpful when choosing a building’s location at the site.
A compact design with a small surface to volume ratio again to reduce heat loss.
South Side Windows should be large to facilitate direct gain. The northern side needs to be well-insulated.
Living areas can be located on the southern side while utility area such as stores can be on the northern side. Lobbies at the entrance and exit points of the building need air lock zone buffers to keep the cold out and reduce heat loss.
The heat generated by appliances in rooms such as kitchens may be used to heat the other parts of the building.
External Spaces
Like hot and dry climate the adjacent building and open spaces need to be clustered together to minimize exposure to cold winds.
Open spaces between buildings should allow maximum solar rays to the building.
Street width can create undesired wind speed increase, theu need to be wide enough to avoid this problem. Source-www.slowlyhome.com/2019/03/01/five-micro-climate-tips-on-how-to-choose-and-design-an-energy-efficient-building-plot/
The street orientation should be east-west to allow for the maximum south sun. The street should be wider to prevent the buildings from shading over each other.
Roof and Walls
The heavy structure envelope and constructional patterns based on the thermal adaptive behaviours of residents could improve the indoor thermal environment.
In summer, semi-basement areas provide maximum thermal comfort, followed by night ventilation.
In winter, passive solar heating and semi-basement are both useful. The indoor air temperature was higher in the bedroom located at the south semi-basement compared with other rooms.
Insulation instead of Ventilation
The roof and the ceilings need feasible internal insulation such as polyurethane foam (PUF), thermocol, wood wool, etc. Aluminium foil is generally used between the insulation layer and the roof to reduce heat loss to the exterior.
The south-facing side of the roof can use a solar air collector hot air from it can be used for space heating purposes.
Source-www.pinterest.com/pin/423197696227443333/
Skylights allow heat gain and provide light in winters. Skylights with shutters for avoiding overheating in summers.
The side which is exposed for maximum solar radiation is advisable to have high thermal capacity such as Trombe wall to store day time heat for later use.
The insulation should have a sufficient vapour barrier on the warm side to avoid condensation.
Vernacular observations
Landform plays a crucial deciding factor for vernacular architecture. The south side of the hill is an ideal location for a building.
Cold Deserts frequently experience snow. The mountainous areas have little vegetation.
Vernacular Materials used Earth, soil, wood, timber, lime, cement, etc., materials that have high thermal capacity and high time lag to reduce heat loss.
The Roof is made of Mud on wooden ballies, timber, bamboo, thatch, etc.
For Instance, the Construction of the Ladakhi Roof includes a layer of rough soil, “markalak” clay, layer of soil on the roof is applied wet, which is a mix that includes straw and organic waste. Ladakhi roof also includes a layer of Ladakhi “yagtses” grass, a traditional stop-gap layer.
The construction of Walls was made with sun-dried mud bricks or rammed earth panels.
Landscape
Deciduous trees are excellent for these climates they provide partly shaded areas and partly sunny. In summer the trees’ leaves shade the building, while in winter the leaves fall allowing sunlight to access the building. Hence, it should be planted in the south and west.
Windbreak trees: help preventing fast temperature dropping, they should be planted in the northwest direction to shelter the building from the winter wind.
Shrubs and bushes when planted on exterior walls to provide moisturized fresh air in the building.
Conclusion
A Cold-dry climate is prevalent at high altitudes in places like Ladakh, Norway, Sweden, etc. The primary attribute a designer has to follow is to maximize the heat gain and minimise heat loss, for occupant comfort.
