Sustainable House

1. Sustainable House

2. Passive Solar Design. Passive solar design is the process of designing and orientating new buildings or modifying existing ones to purposefully capture the suns natural energy. The Romans first discovered that by glazing the south-facing windows and porches of their buildings, solar energy could be trapped, heating the building and keeping the temperature constant into the night. This simple phenomenon is called the "greenhouse effect", today we call a building that uses the greenhouse effect a "passive solar building". The basic principles of passive solar design are;• Orientating buildings to have much larger south-facing windows (more sunlight exposure) than at the north side.• Interior spaces requiring the most heating and lighting should be along the south facing side, with less used rooms (utility room, garage etc.) on the north side.

3. Active Solar Design. Active Solar Heating systems are most commonly used to supply domestic hot water for washing and heating. A collector array (absorber) is mounted on the roof which soaks-up the sun's radiation and increases in temperature, this heats a fluid circulated between the absorber and the water tank, thus heating the water. Enhanced performance systems exist using evacuated glass tubes, which minimise heat losses. These can produce hot water on a cold (sunny) winters day even when temperatures are well below freezing. The UK sits on a northern latitude, which means we receive roughly half the amount of solar energy as some of the sunnier climbs of the world. Theoretically this is still enough to provide all of our water and space heating but in reality seasonal undulations make year-round solar water heating, at present, unrealistic. Installation costs are also currently too high for most (£2000 - £6000). But as the technology becomes more widespread and new buildings are designed to incorporate active solar heating systems as standard, so prices should fall.

4. Photovoltaic (PV) cells. A solar photovoltaic (PV) cell is an electronic device that produces electricity when light falls on it. As the light is absorbed by the PV cell it frees up electrons present in the cell, as the electrons move from the cell, they carry with them an electrical charge and are sent to a load such as a calculator or to storage, such as a battery. A single PV cell can only absorb a small amount of light at a time. So several cells are usually interconnected to form modules to provide larger amounts of electricity. Groups of modules can be mounted together to form a panel. Panels can be interconnected to form a photovoltaic array; these can vary in electrical power depending upon size, from a few watts to thousands. These systems can last a long time; the expected life span is at least 25 years. PV panels and arrays are becoming increasingly popular and being deployed around the world. Their potential as stand-alone systems is recognised particularly in areas where grid-connected electricity is not available. PV panels are also being integrated into existing buildings by replacing the traditional materials of the roofs and facades. Buildings with PV panels which generating more electricity than they use can sell back the surplus power to the national grid.

5. Turf and Green Roofs. The environmental benefits of turf and green roofs are widely recognised, while roof gardens and roof terraces provide much-needed outdoor space in urban areas. Due to the high degree of insulation that they provide, green roofs are known for their ability to provide an extremely constant temperature throughout the year. During the winter they keep the heat in, and in the summer they provide a relatively cool environment. Green roofs also have the ability to soften harsh edges of buildings in sensitive environments, making them blend in with the surrounding area. Turf and green roofs provide habitat for insects and other wildlife. Where new buildings are built on greenfield sites, this new habitat can replace the habitat that would otherwise have been lost

6. Greywater Recycling. "Greywater recycling" is typically defined as being water from the bath, shower, wash hand basin. The ideal situation for ‘Greywater’ is in living accommodation where sufficient amounts are generated daily for reuse in toilets, washing machine and outside tap. Rainwater Harvesting. "Rainwater harvesting" is typically defined as being water collected from roofs via traditional guttering, through down pipes to an underground tank(s). Delivered on demand by an in-tank submersible pump direct to toilets, washing machine and outside tap use. More than 50% of mains water can be substituted by rainwater.

7. Energy Efficient Materials. Insulation High performance, non polluting. “Zero Ozone Depletion Potential (ODP) non-fibrous insulation has emerged from this major study as being amongst the most environmentally sustainable forms of insulation.” Glass ( windows ) Windows have long been used in buildings for day lighting and ventilation. Many studies have even shown that health, comfort, and productivity are improved due to well-ventilated indoor environments and access to natural light. However, windows also represent a major source of unwanted heat loss, discomfort, and condensation problems.