Orientation
Building a passive home relies on good orientation of either your home, your land or both. Get the right orientation and you may be able to eliminate the use of powered heating or cooling methods. Orientation is discussed in terms of how you make use of accessing climatic conditions such as the sun and the wind. You must also take into account external factors such as existing buildings or plantations to get the best results. It is important to note that your regional climate will be the deciding factor in your ideal orientation. Predominantly, my discussion relates to most Australian climates (excluding hot tropical) and is specifically related to our Goulburn Valley region in Victoria.
Knowing your climate Zone
Knowing whether you are in a climatic area that requires more heating or more cooling is important. As well as finding out the actual climatic zone you are situated in, you can analyse your own current energy bills to see whether you rely more on heating or cooling energy. Once you know whether you are looking to make the best use of natural heating or natural cooling, you can start to plan your new home design. (You can find out what zone your local region is by viewing the following page on the “Your Home” Australian government website: http://www.yourhome.gov.au/introduction/australian-climate-zones Or Download the PDF file (Supplied by the Australian Building Codes Board) from the following link to the Your Home Government website. http://www.yourhome.gov.au/sites/prod.yourhome.gov.au/files/pdf/YOURHOME-Introduction-AustClimateZones_4.pdf
Land orientation
Ideally, an energy efficient or passive design home starts with good land orientation. If you know the type of home design you prefer, you can choose your land to suit. The ideal land orientation will give you a large Northerly aspect so that you can maximise passive heating in your main living areas. This should also allow a good quantity of roof space for solar PV panels should you wish to install these. The best land orientation for this scenario would most likely be a block which runs East/West. See diagram from “Your Home” Australian government website (Source: AMCORD). When selecting your land, you should also pay attention to any existing factors such as other buildings or trees for example which may be a hindrance to your design. You want to make sure your good Northerly aspect is not shielded by existing factors.
Home Orientation
To design an energy efficient passive home you must ensure your home faces in the correct direction to take advantage of the natural climate. The best orientation will allow the day time living areas of your home to be facing North (in most Australian climates), allowing good solar access to windows, thus enabling natural heating of your home. It is often best to build on the South boundary to ensure maximum Northerly exposure. In addition, you should avoid exposure of the home to the West as this will generate unwanted heat during the Summer months. Perhaps consider positioning your garage on this side of your home or using a plantation of trees to assist with shading this side of the home. Your orientation should also consider the general direction of local winds as you need to be able to take advantage of cooling breezes during the summer months. Make sure you know which direction your evening wind tends to come from and ensure you design the home to use good cross flow ventilation. This is often achieved by ensuring your South facing windows are opened during the evening and can be enhanced with the Northerly or upper windows being open as well to allow the heat to escape. A home can be amazingly comfortable during both Summer and Winter when the correct principles of home orientation are applied and utilized. Ideal home orientation is shown in the diagram for this blog, from “Your Home” Australian government website (Source: SEAV). In this diagram you can see good access for the solar PV panels, large North facing windows to heat the home during Winter and no windows on the West side of the home, which will counteract the Summer heat from penetrating the home. At Solar City Eco Homes we have a unique design for the West facing wall to minimise heat transferring into your home.
If you’re looking to build an energy efficient home, we’re happy to answer your questions and point you in the right direction. Call Andrea on 0420 296 061 for more information or take a look at our facebook page by following this link: http://bit.ly/SolarCityEcoHomesFB