Houses Designed to Save Energy
A house can be designed to save energy and resources in three ways: with efficient design (using locally-sourced sustainable materials); efficient insulation, quality windows; mechanical systems and efficient technology. Build an energy-efficient home isn’t an easy task but following these tips you can deal with it.
Larger houses use more energy to heat and cool, and use more materials in their construction.
• A low impact of ‘footprint’ is ideal. This could mean a house that has minimal foundations or that its construction respects the land by minimal site disruption – keeping topsoil and minimizing polluted wastes from seeping into the ground, etc.
• By heating high mass areas of a house, such as the floors or walls, spaces are heated by surfaces, not the other way around.
• The building should be oriented with its major axis about 15 degrees East of North, to ensure an adequate amount of passive heating in winter.
• Position windows to benefit from solar rays and natural light: place large windows in areas receiving less sun exposure, and vice versa. For optimum solar efficiency, the surface area of windows facing North should be around 19% of the floor area.
• Insist on double-glazing or low emissive glass that reflects heat and harmful ultraviolet rays; double glazed windows trap and prevent interior heat from escaping. Avoid metal and PVC windows – consider local timber or insulated aluminum.
• Include pergolas and deep overhanging eaves (keeping the sun off walls) to help block the hot summer sun, keeping the house naturally cool. Windows positioned in corners or along floors optimize the reflectivity of the light on surfaces perpendicular to the windows.
• Concrete is a great heat retainer, releasing it slowly into space. Concrete floors with radiant-heated floors fed by solar tubes or a geyser on the lower level will slowly warm the concrete into a thermal mass, while a forced-air system connected to the geothermal system can be used upstairs.
• Insulate floors, walls, and ceiling spaces. Insulating your walls can reduce your heating bills by up to 30% – and are also great for sound control. Walls on the hotter sides can be built doublewide or as cavity walls with insulation.
• An automated control system can tie together the lights, shades, thermostats, and other electronics into one easy-to-use system. Motorized blinds automatically shade large windows to keep the rooms cool, and natural ventilation reduces the need for air conditioning.