Orientation of Building

BUILDING ORIENTATION MEANING ?

The term “building orientation” refers to the compass direction the building faces or the positioning of a building in relation to the seasonal variations (suns path, existing wind patterns and rainfall).

When deciding the orientation for your home, keep in mind to make best use of sunlight and winds, which can increase the energy efficiency of your building, making it cheaper to run and more comfortable to live in. 

FACTORS AFFECTING ORIENTATION:

☞︎︎︎  Solar radiation , for which it is essential to know path of sun throughout the year and its relative position w.r.t the locality.

☞︎︎︎  Rainfall which means the direction and intensity of the rain.

☞︎︎︎  Prevalent wind which means direction of prevailing wind in summer and in winter.

☞︎︎︎  Site condition means the location of the site (urban, rural etc).

THE PRINCIPLE OF GOOD ORIENTATION

☞︎︎︎  The building should receive maximum solar radiation in winter and minimum solar radiation in summer.

☞︎︎︎  For hot and humid zones the orientation is governed by the direction of the breeze.

☞︎︎︎  In hot climates living rooms on the South and West sides should be protected by varandah, bathroom, store etc.

☞︎︎︎  In hot humid zones and hot dry zones with no winter heating requirements, aim to exclude direct sun by shady trees on sunny side and also by keeping the shorter walls on East and West.

☞︎︎︎  All the rooms which are occupied in the day time should preferably be placed on North and East side.

☞︎︎︎  The bedrooms should be placed in the direction of prevailing wind and at the same time protected by verandah from the heat of afternoon Sun.

☞︎︎︎  North-facing walls and windows receive more solar radiation in winter than in summer.

☞︎︎︎  The optimum balance between capturing sunlight and capturing cooling breezes is determined by heating and cooling needs.

BUILDING ORIENTATION BASED ON CLIMATIC CONDITIONS OF INDIA

Building orientation is an important criteria but another aspect to keep the interiors also climate friendly is the orientation of the voids (windows, ventilators etc).

Accordingly, India can be divided into four zones for climate point of view:

a. Hot-arid

b. Hot-humid

c. Moderate

d. Cold

a. Hot-Arid Regions or Zones

𝙴𝚡𝚝𝚎𝚛𝚒𝚘𝚛 𝙾𝚛𝚒𝚎𝚗𝚝𝚊𝚝𝚒𝚘𝚗 :- The main criteria here is to minimize the direct exposure of the built from the sun in summer and in winters the shade should be transformable enough to let the sun in, which can be achieved by building larger face along north-south.

𝙸𝚗𝚝𝚎𝚛𝚒𝚘𝚛 𝙾𝚛𝚒𝚎𝚗𝚝𝚊𝚝𝚒𝚘𝚗 :- 🅐︎. The bedroom should be located on the East side whereas the living room on the North or South side. 🅑︎. The walls on the outer faces should be made thick enough to resist heat and the material used should be bad conductor of heat. 🅒︎. Openings should be provided for natural light and ventilation. 🅓︎. Flat roofs provided reflective colour painting with minimum number of opening should be provided on the roofs to reduce the heat gain from sun. 🅔︎. Cooling can be achieved by evaporation of water, by using passive cooling.

𝚅𝚎𝚐𝚊𝚝𝚊𝚝𝚒𝚘𝚗 𝙾𝚛𝚒𝚎𝚗𝚝𝚊𝚝𝚒𝚘𝚗 :- Planting deciduous trees is very useful in hot and arid to cut off hot breezes.

b. Hot-Humid Regions or Zones

𝙴𝚡𝚝𝚎𝚛𝚒𝚘𝚛 𝙾𝚛𝚒𝚎𝚗𝚝𝚊𝚝𝚒𝚘𝚗 :- The structures planned needs to be oriented away from each other for cross ventilation without any obstructions. The east-west slopes receives more sun radiation than north-south slopes. So generally the settlement should be on North or South slopes, facing away from the equator.

𝙸𝚗𝚝𝚎𝚛𝚒𝚘𝚛 𝙾𝚛𝚒𝚎𝚗𝚝𝚊𝚝𝚒𝚘𝚗 :- 🅐︎. Cross ventilation should be provided such that heat trapping at corner is avoided. 🅑︎. There should be provision of green terraces in high rise buildings. 🅒︎. Maximum shading should be provided to resist the solar radiations.

𝚅𝚎𝚐𝚊𝚝𝚊𝚝𝚒𝚘𝚗 𝙾𝚛𝚒𝚎𝚗𝚝𝚊𝚝𝚒𝚘𝚗 :- Tall trees should be provided such that they provide shade and do not hinder the flow of air.

c. Moderate Climate Regions or Zones

A building reacts with environment (solar radiation, wind) through its external front.

In moderate climate, the average temperature difference is not drastic and does not reach extreme conditions.Thus, the design can be flexible enough to suite the climatic conditions.

d. Cold Climate Regions or Zones

In cold climate zones it is preferred to orient the house on the top of the slope not at the bottom to avoid katabatic winds (fall winds).

Proper restrictions to the cold breezes must be made. Vegatation can block the sun radiation which is much important in cold regions.