Building Orientation

Orientation

• What compass direction the building faces– Directly south, 80 east-northeast

• Along with massing can be the most important step in providing a building with passive thermal and visual comfort

• Orientation and massing cannot be optimized without the other

Orientation

• Measured by the azimuth angle of a surface relative to true north

• Successfully the building is rotated to maximize free energy from the sun and wind and minimize energy loads

• Can also take advantage of other site conditions, such as rainwater harvesting driven from prevailing winds

For Visual Comfort

• Oriented east to west rather than north south– Consistently harness daylight and control glare

along the long faces– Minimize glare from rising/setting sun

• With cutouts to maximize daylighting you should try to also max N/S walls– Can also provide their own shading

Orientation for Thermal Comfort:Solar Heat Gain

• Similar to orientation for daylighting with some exceptions– Amount of sunlight that is optimal for daylighting

is often not optimal for solar heat gain– Sun’s heat does not come from all directions like

the light does– Heat can be stored via thermal massing• Useful for west facing walls to store heat at night

• Buildings longer than they are wide should be oriented east-west rather than N-S

• Lets you consistently harness thermal gain or avoid along the long face of the building

• Also minimize the area that’s subject to faster energy swings from rising/setting sun

• Solar heat gain can be useful in the am on the east side, not on the west side after a warm day

Glazing and Materials on Diff Faces

• Part of a building’s orientation• Unlike daylighting they can store the sun’s

heat with thermal mass• Equator facing sides are well suited to capture

and store the sun’s heat via large windows and materials with high thermal mass

• To even out temp swings at sunrise/set east sides may have more windows for direct solar heat gain

• West side may benefit from smaller windows and high thermal mass to absorb heat and release it at night (depends on the climate)

• In cold climates sides facing away from the sun will benefit from more insulation than sides

• Opposite is true for warm climates

Natural Ventilation

• Oriented to maximize the benefits of cooling breezes in hot weather or shelter from in cold weather

• Look at the prevailing winds for your site through the year using the wind rose diagram

Ventilation

• Orienting the building with the shorter axis aligned to the prevailing wind provides the most ventilation– Perpendicular provides the least passive

ventilation

Ventilation

• Do not need to face directly into the wind to achieve good cross ventilation

• Design to channel air through the building• Look at site obstructions that may affect the

directions• A courtyard where cooling is desired should

be at 45 from the prevailing wind– Maximize wind in the courtyard and cross

ventilation through the building