The purpose of 'green' and 'energy efficient' building practices and design is to simply reduce the environmental impact of buildings and best utilize natural heating, cooling and lighting elements of the NATURAL local climate.
With so much emphasis on "going green", (and rightly so if we are to reduce our impact on the planet), energy efficiency is an important consideration when making decisions in regard to your home design, whether it be a renovation or a completely new home.
In this article we will talk a little about how to best utilize your building site with energy efficiency in mind via orientation and also taking into account your local climate.
Rule #1: Orientate your home to create 'zones' within your home. Living areas should face NORTH. By positioning your living areas and the areas you will be spending most of your time in during the day with a northerly perspective, you will maximize the amount of sunlight these areas attract right throughout the day as the sun travels across the sky. Remember that in Australia the sun does not travel directly overhead, but is slightly north due to Australia's lower sub-equatorial location on the planet.
Variations from true north that are relatively acceptable are 20deg west or 30deg east. In either of these cases, extra shading in the form of overhang or even a patio roof, may need to be considered for summer.
Living areas that utilize 'open plan' design are desirable as it allows the best use of space available, it allows sunlight to enter the largest area home resulting in heating and lighting, and allows air to circulate freely around the home contributing to multiple ventilation flow paths through to other rooms.
Bedrooms and utility rooms should face SOUTH so as to stay cooler day and night. These may also be able to be located with a northerly perspective, but obviously will encourage more lingering heat into the evening and nighttime hours.
Zone your living areas so that they can be closed off from the rest of the building, therefore reducing the area that needs to be heated of cooled. The smaller the room size the less energy required to heat or cool.
Natural cooling using cool breezes. Each climate area has prevailing winds. Locate your windows towards areas where you will receive the cooler breezes. If you are new to the area, simply asking neighbours where the best breezes come from will help you in deciding window details on your design.
Rule #2: Adequate distance from neighboring buildings. If the site allows for this, you can ensure that other buildings do not encroach on your 'energy efficiency' planning and you have total control over your home's climate design. To minimize overshadowing of other buildings during the day, minimum distance should be 6 meters from a neighboring single storey home, and 11 meters from a double storey home.
This is not always possible of course due to the nature of most city and town blocks, so to compensate for this, height is your friend. If overshadowing from other buildings will be an issue due to your particular site, lifting your building to a height that eliminates this problem is the next consideration so as to minimize the impact of surrounding buildings on your home.
Another option is to utilize "clearstory" windows located above your main window/door joinery. These are high windows often located high on a wall in a 'raked' ceiling design between a lower and higher roof. These allow more light in during the day, helping to overcome the overshadowing issues. Though during summer, you may need additional shading for these windows.
So in this brief look at energy efficiency through home orientation, we have examined just one important aspect of energy efficient design. Check back soon for more articles on sustainable living and home design.