Building Orientation – Principles And Analysis Of The Best Orientation

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Building orientation is an essential aspect of passive design, which is an approach to building design that maximizes the use of natural energy flows and minimizes reliance on mechanical systems for heating, cooling, and lighting. A well-designed building orientation can significantly reduce the energy requirements of a building and improve its overall comfort.

Orientation

Orientation is the positioning of a building in relation to seasonal variations in the sun’s path as well as prevailing wind patterns.
Good orientation can increase the energy efficiency of your building, making it more comfortable to live in and cheaper to run.

Identify your climate zone and develop an understanding of appropriate design responses by referring to Design for Climate.

Orientate your home to make the best use of sunlight and winds.

Principles of good orientation

Good orientation, combined with other energy efficiency features, can reduce or even eliminate the need for auxiliary heating and cooling, resulting in lower energy bills, reduced greenhouse gas emissions, and improved comfort.
It takes account of summer and winter variations in the sun’s path as well as the direction and type of winds, such as cooling breezes.
Good orientation can help reduce or even eliminate the need for auxiliary heating and cooling, resulting in lower energy bills, reduced greenhouse gas emissions, and improved comfort.

In hot humid climates and hot dry climates with no winter heating requirements, aim to exclude direct sun by using trees and adjoining buildings to shade every façade year-round while capturing and funneling cooling breezes.

In all other climates a combination of passive solar heating and passive cooling is desirable.

North orientation is generally desirable in climates requiring winter heating because the position of the sun in the sky allows you to easily shade northern façades and the ground near them in the summertime with simple horizontal devices such as eaves while allowing full sun penetration in winter.

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

Average daily solar radiation on vertical surfaces.

Orientation for passive heating

Sun movement from a high angle in summer to a low angle in winter.

Orientation for passive heating is about using the sun as a source of free home heating by letting the winter sun in and keeping unwanted summer sun out.
It can be done with relative ease on northern elevations by using horizontal shading devices to exclude high-angle summer sun and admit low-angle winter sun.

‘Solar access’ is the term used to describe the amount of useful sunshine striking glass in the living spaces of a home.

The desired amount of solar access varies with climate.

The sun is a source of free home heating.
First, establish true or solar north for your region.
This is useful in all climates whether you are encouraging or excluding solar access.
Ideal orientation (in most climates) is solar north, orientations of up to 20° west of north and 30° east of north still allow good passive sun control.
Variations in orientation towards east and west can have advantages in some climates and for some activities.

In cold climates, orientations west of north increase solar gains in the afternoon when they are most desirable for evening comfort, but east of north can warm the house more in the mornings, improving daytime comfort for those who are at home then.
In warmer climates, orientations east or north can allow better capture of cooling breezes.

Poor orientation and lack of appropriate shading can exclude winter sun and cause overheating in summer by allowing low-angle east or the west sun to strike glass surfaces at more direct angles, reducing reflection and increasing solar gains.
Orientation does not have to be precise: there is a degree of flexibility.