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Choosing the place and which way to face. What should you think about when deciding where to put your building? The direction a building faces will impact on a lot more than the view – how do you decide the best orientation?. Location, location, location.
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Choosing the place and which way to face What should you think about when deciding where to put your building? The direction a building faces will impact on a lot more than the view – how do you decide the best orientation?
Location, location, location Early planning will need to consider where and how a building is located. There are several angles to consider when answering the question – where shall I put it? • is the land you plan to use in a rural or urban setting? • is it a brown or green field site? • what’s the local micro-climate like? • are there any special ecological features that should be safeguarded before, during or after construction? • will your building and landscaping add value to the site? • is the building oriented to maximise potential solar gains and minimise exposure? Being located on a south facing slope with large amounts of glazing results in solar gain. .For more info go to bldgs-siting_and_orientation.htm Good design uses natural features such as slopes or vegetation to shelter buildings from the wind and maximise solar gains. A significant reduction in heat loss can be achieved through properly planned siting.
Form and shelter • How can you protect a building from: • wind • rain • sun • temperature variations http://www.dreamgreenhomes.com/plans/esactivehome.htm The shape and size of a building influences heat transfer. Compact buildings that have a small ratio of surface area to volume will loose less heat. Apartments also benefit from sharing warmth with adjacent properties compared with detached houses.
Gaining from solar rays The sun’s rays can warm a building: glazing on the south side of buildings will increase this ‘solar gain’. The sun is higher in the sky in the summer, large over hangs reduce heat gains in summer but allow solar gain in winter. Attached sun spaces trap heat from the sun. Direct and indirect energy transfer provides heat to the adjacent building. At Hockerton Housing glazed verandahs gain heat from the sun’s rays. The floor and walls then heat the rest of the building. In the winter such buffer zones separate the cold outside and the warm inside. Hockerton Housing Project
Massive gains How can thermal mass be used to save energy? Thermal mass is the ability of a material to absorb heat energy. A lot of heat energy is required to change the temperature of high density materials like compacted earth, concrete, bricks and tiles. They have a high thermal mass. Lightweight materials such as timber have a low thermal mass. WinterAllow thermal mass to absorb heat during the day from direct sunlight or from radiant heaters. It will re-radiate this warmth back into the home throughout the night. The thermal mass of building components like floors, walls and roofs can be designed to capture energy when it is plentiful (or excessive), store it and release it later. SummerAllow cool night breezes, convection currents, to pass over the warm thermal mass, drawing out all the stored energy. During the day protect thermal mass from excess summer sun with shading and insulation if required. This rammed earth wall at CAT warms up when the sun hits it. At night, or when the temperature decreases, the heat stored in the wall is released keeping the building temperature more constant and reducing the heating demand.
Check…… • In which direction should your building face? • How can your building be sited to minimise heat loss? • How can your building be sited to maximise use of heat from the sun (solar gain)? • How can your building be sited to utilise natural elements so it’s warm when you want it to be warm (e.g. winter, evening, night) and cool when you want it to be cool (e.g. summer, daytime)? • Can you make use of existing natural features of your chosen site (e.g. re-using materials, vegetation for shade, earth for wind protection, slopes for solar gain)? • Can you site it so it doesn’t create problems (e.g. visibility, sun loss) for other buildings or so that other buildings don’t create similar problems for yours?
Why…… • do you think this house has been orientated in this direction? • are the solar panels positioned where they are? • are the windows very different sizes? • is there a porch? • Have a look at http://www.buildingwithawareness.com if you’re not sure of the answers.
