Passive solar design and building layout

Passive solar design

Passive solar design is the design of a building so that it collects, stores and distributes solar energy for heating (and rejects it for cooling) by the form, orientation and materials of the building itself, without mechanical equipment.

Importance

• Reduces energy for heating, cooling and lighting, and so saves money.
• Gives thermal and visual comfort.
• Has low maintenance and running cost, with no moving parts.
• Reduces use of fossil fuel, firewood and pollution; useful in Nepal's cold hills and mountains.
• Increases building life and value, and gives more daylight.

Setting layout plan of building

1. Place the building with its long axis east-west, so the long face looks south (within 15° of south).
2. Put living and working rooms, with large glazing, on the south side. Put stores, toilets, stairs and garages on the north as a buffer.
3. Keep east and west walls with few and small openings.
4. Use overhangs, chhajja, or deciduous trees on the south side to give shade in summer and let the low winter sun in.
5. Keep buildings spaced so that each is not shaded by the next one (sun angle at winter solstice).
6. Plant evergreen trees on the north-west side as wind-break against cold winds.

            N  (stores, toilets)
        +---------------+
   W    | bed |  kitchen|    E
        |---------------|
        | living (glass)|
        +---------------+
            S  sun -> 
          [tree, deciduous]