The way people live has constantly changed over thousands of years. From caves that sheltered early man, to wooden cottages in medieval times to terraced houses in the modern era. We have built houses to suit our needs that have changed as our societies developed in the course of human history. The location where the first human settlements where built was also crucial to man’s survival. The area where they lived had to be life supportive, meaning that the climate had to be appropriate for animals, insects (bees that pollenate) and nature’s necessities (grapes, plants, flowers etc.)
As the development in agriculture accelerated after the last ice age some 12,000 ago, societies immigrated to regions further north and south. Agricultural practices such as raising, grazing, cultivation and irrigation has enabled humans to stay in one place instead of travelling around searching for food. Villages emerged and the population grew.
The industrial revolution in the late 1700’s trigged the growth of cities as houses for the workers were built around factories. The conditions of the terraced houses back then were very poor with very little room and poor sanitation. As the rights of the workers improved, so did their living conditions. Today, the terraced houses are still a popular choice amongst many working class people and young families. Row houses are the one of the most common types of housing in the world.
As the demand for houses in most parts of the world increases because of population growth and the effects of climate change become clear, so does the need for a more energy efficient type of housing. The low-energy house or eco-home is a type of house that from design, technologies and building materials uses less energy, than any other traditional type of house.
Obviously, there will be energy efficient houses with different shapes and designs, however the one illustrated above provides a clear idea of the kind of style that is used in sustainable architecture.
Most of us have a good idea of what sustainable architecture is; a house that is built from using sustainable materials and that generates its own heat and electricity by using solar panels and heating systems. However, what kind of sustainable materials are used? How do solar panels generate electricity and how exactly do heating systems work? These and other aspects of green architecture will be focused on.
How Photovoltaic Solar Panels work
Basically, photovoltaic solar panels create electricity by converting sunlight into energy. The process by which this happen is known as the photovoltaic effect. “Photovoltaic” essentially means light electricity. (© 2013 Online Solar, LLC&MrSolar.com)
When sunlight hits the panel (usually made of semiconducting silicon), the photons in the sunlight free electrons from the atoms in the photovoltaic material so they can flow out of the cell as an electric current. When the electrons are forced to move in one direction, they become electric current. An inverter is needed to convert the direct current into alternating current we use in our homes. (OurChoice, Al Gore 2009)
How Solar Heating Systems work Solar thermal systems use the sun’s warmth to heat the water inside homes. Fluid inside solar panels on a roof absorbs irradiance from the sun. It is then pumped along pipes to the hot water cylinder, heating up the water to a pre-set temperature. The boiler will then provide the heat when needed, bringing the water to the temperature on the thermostat. (© 1st Choice Solar 2011)
Sustainable Building Materials
Besides installing solar panels and heating systems, green architecture is also about using sustainable building materials in the construction of houses.
Below are five examples of sustainable building materials that can be used in the construction of eco homes. (Source: http://thisbigcity.net)
Developed by Spanish and Scottish researchers with an aim to ‘obtain a composite that was more sustainable, non-toxic, using abundant local materials that would mechanically improve the bricks’ strength’, these wool bricks are exactly what the name suggests. Simply by adding wool and a natural polymer found in seaweed to the clay of the brick, the brick is 37% stronger than other bricks, and more resistant to the cold wet climate often found in Britain. They also dry hard, reducing the embodied energy as they don’t need to be fired like traditional bricks.
Traditional roof tiles are either mined from the ground or set from concrete or clay – all energy intensive methods. Once installed, they exist to simply protect a building from the elements despite the fact that they spend a large portion of the day absorbing energy from the sun. With this in mind, many companies are now developing solar tiles. Unlike most solar units which are fixed on top of existing roofing, solar tiles are fully integrated into the building, protecting it from the weather and generating power for its inhabitants.
Sustainable concrete is a type of concrete that uses recycled materials in the mix. Crushed glass can be added, as can wood chips or slag – a byproduct of steel manufacturing. Whilst these changes aren’t radically transforming concrete, by simply using a material that would have otherwise gone to waste, the CO2 emissions associated with concrete are reduced.
Made from recycled newspapers and cardboard, paper based insulation is a superior alternative to chemical foams. Both insect resistant and fire-retardant thanks to the inclusion of borax, boric acid, and calcium carbonate (all completely natural materials that have no associations with health problems), paper insulation can be blown into cavity walls, filling every crack and creating an almost draft-free space.
Super-efficient windows would better describe this particular building material. The three layers of glass do a better job of stopping heat from leaving the building, with fully insulated window frames further contributing.
In most double-glazed windows, the gas argon is injected between each layer of glass to aid insulation, but in these super-efficient windows, krypton – a better, but more expensive insulator – is used. In addition to this, low-emissivity coatings are applied to the glass, further preventing heat from escaping.(source: Thisbigcity.net, Nov 2010 by Joe Peach ©Creative Commons 3.0)
Green architecture – the new way forward
As sustainability is gaining importance across the world, people are starting to realise that ‘going green’ is the new way forward now and in the future. Not only is there a transition from the ‘old thinking’ (more consumption, materialism etc.) to the new thinking of buying for example, more eco-friendly products, but also living in a sustainable way is becoming more important to us as well. Therefore, green architecture is gaining popularity amongst many nations including: Norway, South Africa, Germany, Britain, the United States and Canada.