Orientation and planning of a building

Orientation of a building is the placing of the building on the site, and the arrangement of its rooms, so that the sun, wind, rain and view are used to give comfort inside with the least artificial heating, cooling and lighting.

Factors for orientation

1. Sun path and solar radiation: In Nepal (about 27°N–30°N) the sun is in the southern sky. Long walls and large windows should face south to receive winter sun. East and west walls get low-angle sun, so openings there should be small.
2. Wind direction: The prevailing wind (in the Terai, mostly west to east in summer) should reach the main openings for cross ventilation. The long face with the openings should face the wind, with the wind within about 0° to 30° of the normal to the wall, not parallel to it.
3. Rainfall: The direction of driving rain decides where sheds, eaves and chhajja are needed.
4. Topography and view: Slope, drainage, and a good view or privacy may change the best direction.
5. Climate zone: The hot-humid Terai needs shade and ventilation; the cold hills need solar gain and a compact form.
6. Surroundings: Nearby trees, buildings and noise sources can shade the building or block the wind.

Factors for planning

• Aspect: Each room faces the direction suited to its use: kitchen east/north-east (morning sun, away from afternoon heat), bedroom south-east or south, living room south, store and toilet north or west.
• Prospect: The view outward from the openings.
• Grouping: Rooms of related use are placed together to shorten circulation.
• Roominess: Right sizes and proportions for the furniture and activities.
• Privacy: Bedrooms and toilets are screened from the road and neighbours.
• Circulation: Short, direct passages and stairs with little wasted area.
• Furniture requirement and sanitation: Wall space for furniture; light, ventilation, clean water and drainage.
• Flexibility and economy: Space can be altered later, and the plan is compact so that the cost is low.
• Bye-laws: Setback, ground coverage, floor area ratio and height as per the Nepal Building Code and municipal bye-laws.

        N
   [Store][Toilet]
 W [Kitchen][Dining] E
   [Living][Bedroom]
        S  (large windows)