Ecohouse

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Ecohouse near Faaker See, Austria Ecohouse near Faaker See, Austria.JPG
Ecohouse near Faaker See, Austria

An Eco-house (or Eco-home) is an environmentally low-impact home designed and built using materials and technology that reduces its carbon footprint and lowers its energy needs. Eco-homes are measured in multiple ways meeting sustainability needs such as water conservation, reducing wastes through reusing and recycling materials, controlling pollution to limit global warming, energy generation and conservation, and decreasing CO2 emissions.

Contents

An Eco-house could include some or all of the following:

Building concepts

Energy loss

Thermal insulation is the main component of preventing energy loss. Thermal insulation.jpg
Thermal insulation is the main component of preventing energy loss.

Buildings use up enormous amounts of energy. Home energy as well contributes to global warming. According to The Energy Information Administration, home energy contributes to 21% of all greenhouse gases in the United States alone. In construction as well, 48% of greenhouse gases is emitted. [1] Some calculations make it as much as 70% of all the energy used when all the factors are taken into account. This energy is mainly for heating and lighting and therefore the aim is to design houses that are well insulated and make the best use of natural light. [2]

Insulation

Increasing the amount of thermal insulation is the main component of preventing energy loss. According to the EPA Office of Air and Radiation, indoor air is more polluted than outdoor air, and is in the top five human health risks. Such pollution could be caused by toxic chemicals and mold and could lead to asthma induced illnesses. Insulation in Eco-homes include draft exclusion, glazing, wall, roof insulation, and other nontoxic materials. By installing insulation not only are you paying less money for heating bills, but you are also reducing exposure to toxic materials such as the carcinogen formaldehyde found in manufactured wood. [1]

Passive solar gain

In the northern hemisphere, a south-facing site will be a much better location than a north facing site because of access to sunlight and protection from the cold northerly wind. An eco-house starts life facing the Sun. [2]

Ideally, the site for the house should have a south westerly aspect and be protected from the north and east. It is not always possible to do this but there will usually be an opportunity to take advantage of the passive solar gain by having more glazing on either the front or the back of the building. Planting trees and creating windbreaks on the north and east sides of the site can enhanced the solar gain effect by protecting the house from the cold north easterly winds.

Having faced the house towards the Sun, high performance windows are used to draw in as much light and warmth as possible. Sunlight then floods into the house and any heat generated is retained by a highly insulated building shell, draught proof windows and doors and thermal mass within the building. [2]

Active solar gain

Electricity-generating solar panels on roof Solar panels on a roof.jpg
Electricity-generating solar panels on roof

Orientation towards the Sun also means that active solar systems can be fitted, both solar water heating panels and electricity generating solar panels on the roofs, further adding to the free heat and electricity gained from the sun. [2]

Living gain

Living in the house also generates heat. Active human beings can produce as much heat as a one bar electric fire. Add to this heat from cooking, washing, lights etc. and you can begin to see how an eco-house could get too hot. Conventionally opening the windows reduces heat, but an eco-house design could include heat recovery ventilation systems. [2]

Heat recovery ventilation

These systems extract the warm, moist air from bathrooms and kitchens and take the heat out of the stale, damp air before venting it outside. The heat recovery system transfers this collected heat to fresh air coming into the building and distributes it to the bedrooms and living rooms, which creates fresh air at room temperature. An added benefit is that filters can be fitted on the air intake to provide a barrier to pollen or other irritants. [2]

Living heat loss

With the passive and active solar gains, insulation, draft proofed building shell and heat recovery system, eco-houses could be zero heat; that is, in theory, one should not need to keep pumping heat into them from a central heating system. In practice, heat loss inevitably occurs as the inhabitants open the home's doors and windows for various reasons. An eco-house can incorporate design to have heating systems that can react quickly and efficiently to any changes in room temperature as well as providing a heat boost to the water temperature down-stream of the solar panels. [2]

Sustainable materials

One of the wider issues of energy efficiency is the embodied energy within the construction materials. (Embodied energy is the energy taken up with producing and transporting the materials used). [2]

Timber

Wood is a primary building material for eco-housing. This is because trees grow using energy from the Sun, do not pollute, produce oxygen, absorb CO2, provide a wildlife habitat, can be replanted, can be sourced locally, and the timber can be put to some other use after a building is demolished. [2]

Lime is a sustainable material for energy efficiency. Furillen lime stone pile.jpg
Lime is a sustainable material for energy efficiency.

Lime

Cement is a very useful building material and there are places where we have to be practical and use it. However, one alternative to cement is lime. Lime has been used as a building material for thousands of years and although energy and CO2 are used in its production it gently returns to limestone in time, taking in CO2 in the process. [2]

Reclaimed materials

There is also the use of reclaimed materials, particularly bricks, slates and roof tiles, to make use of the embodied energy within these materials. This can also help new buildings to blend in with their surroundings. [2]

Health

Other benefits of an Eco-house, aside from having minimal heating costs, are a healthy living environment. The heat recovery system can eliminate dampness and hazardous mold growth. The air intake filters prevent dust coming in with the incoming fresh air and the internal vacuum cleaner system extracts dust from the house and vents it (via the dust collection bag and filter) to the outside; thus no microscopic particles of dust remain in the house.

Load bearing internal walls are minimised to allow rearrangements of the interior spaces, and the build technology is such that local trades can carry out alterations and easy maintenance.

For the health of the householder, and the planet, an Eco-house should be built with materials that are free, wherever possible, from toxins or harmful products of the petro-chemical industry. [2]

The better indoor environmental quality of Eco-houses has also improved health and satisfaction among occupants by reducing exposure to pollutants, allergens, and other contaminants. According to Dr. Joseph Allen and his research at Harvard T.H. Chan School of Public Health, this leads to inhabitants of Eco-houses suffering less from sick building syndrome while maintaining positive mental and physical stability. [3]

Costs

An example of affordable eco-house (Australia) Tasmanian House by Jiri Lev.jpg
An example of affordable eco-house (Australia)

Generally, Eco-houses are labelled as costly and expensive for the average citizen to afford. Perceptions of costs are one of the main issues for many builders and owners. This perception is induced by the medias coverage of Eco-houses built according to the standards of above average income homeowners. According to SmartMarket Report, around two-thirds of Eco-house owners, who built their own homes, had an annual budget of over $50,000. This above average income and the freedom in building their own design, furniture, and materials for their Eco-houses attributes to the addition of more expensive features, but this does not mean there are not affordable Eco-houses on the market. It all depends where you allocate your money. [1] Builders of Eco-houses are also taking initiatives to reduce the costs associated with general homes. The main factors contributing to cost for any house includes land, planning, infrastructure, professional fees, accreditation, compliance fees, labour, materials, market, and occupation. With this being said, initiatives being done to reduce house costs for Eco-houses are directed towards materials and the market. In decreasing material costs, Eco-house builders use reclaimed materials. Eco-house builders can also gain community land trust for ownership of land. For example, in Colorado, US, Eco-builders were able to eliminate costs by building on cheap land in an absent location while using reclaimed materials. With building in a remote location, the Colorado Eco-builders eliminated land costs. [4]

See also

Related Research Articles

An autonomous building is a building designed to be operated independently from infrastructural support services such as the electric power grid, gas grid, municipal water systems, sewage treatment systems, storm drains, communication services, and in some cases, public roads.

A Trombe wall is a massive equator-facing wall that is painted a dark color in order to absorb thermal energy from incident sunlight and covered with a glass on the outside with an insulating air-gap between the wall and the glaze. A Trombe wall is a passive solar building design strategy that adopts the concept of indirect-gain, where sunlight first strikes a solar energy collection surface in contact with a thermal mass of air. The sunlight absorbed by the mass is converted to thermal energy (heat) and then transferred into the living space.

<span class="mw-page-title-main">Passive solar building design</span> Architectural engineering that uses the Suns heat without electric or mechanical systems

In passive solar building design, windows, walls, and floors are made to collect, store, reflect, and distribute solar energy, in the form of heat in the winter and reject solar heat in the summer. This is called passive solar design because, unlike active solar heating systems, it does not involve the use of mechanical and electrical devices.

<span class="mw-page-title-main">Thermal mass</span> Use of thermal energy storage in building design

In building design, thermal mass is a property of the mass of a building that enables it to store heat and provide inertia against temperature fluctuations. It is sometimes known as the thermal flywheel effect. The thermal mass of heavy structural elements can be designed to work alongside a construction's lighter thermal resistance components to create energy efficient buildings.

<span class="mw-page-title-main">Solar thermal collector</span> Device that collects heat

A solar thermal collector collects heat by absorbing sunlight. The term "solar collector" commonly refers to a device for solar hot water heating, but may refer to large power generating installations such as solar parabolic troughs and solar towers or non water heating devices such as solar cooker, solar air heaters.

<span class="mw-page-title-main">Heat recovery ventilation</span> Method of reusing thermal energy in a building

Heat recovery ventilation (HRV), also known as mechanical ventilation heat recovery (MVHR), is an energy recovery ventilation system that operates between two air sources at different temperatures. It's a method that is used to reduce the heating and cooling demands of buildings. By recovering the residual heat in the exhaust gas, the fresh air introduced into the air conditioning system is preheated, and the fresh air's enthalpy is reduced before it enters the room, or the air cooler of the air conditioning unit performs heat and moisture treatment. A typical heat recovery system in buildings comprises a core unit, channels for fresh and exhaust air, and blower fans. Building exhaust air is used as either a heat source or heat sink, depending on the climate conditions, time of year, and requirements of the building. Heat recovery systems typically recover about 60–95% of the heat in the exhaust air and have significantly improved the energy efficiency of buildings.

<span class="mw-page-title-main">Low-energy house</span> House designed for reduced energy use

A low-energy house is characterized by an energy-efficient design and technical features which enable it to provide high living standards and comfort with low energy consumption and carbon emissions. Traditional heating and active cooling systems are absent, or their use is secondary. Low-energy buildings may be viewed as examples of sustainable architecture. Low-energy houses often have active and passive solar building design and components, which reduce the house's energy consumption and minimally impact the resident's lifestyle. Throughout the world, companies and non-profit organizations provide guidelines and issue certifications to guarantee the energy performance of buildings and their processes and materials. Certifications include passive house, BBC - Bâtiment Basse Consommation - Effinergie (France), zero-carbon house (UK), and Minergie (Switzerland).

<span class="mw-page-title-main">Passive house</span> Type of house

Passive house is a voluntary standard for energy efficiency in a building, which reduces the building's ecological footprint. It results in ultra-low energy buildings that require little energy for space heating or cooling. A similar standard, MINERGIE-P, is used in Switzerland. The standard is not confined to residential properties; several office buildings, schools, kindergartens and a supermarket have also been constructed to the standard. The design is not an attachment or supplement to architectural design, but a design process that integrates with architectural design. Although it is generally applied to new buildings, it has also been used for refurbishments.

Low emissivity refers to a surface condition that emits low levels of radiant thermal (heat) energy. All materials absorb, reflect, and emit radiant energy according to Planck's law but here, the primary concern is a special wavelength interval of radiant energy, namely thermal radiation of materials. In common use, especially building applications, the temperature range of approximately -40 to +80 degrees Celsius is the focus, but in aerospace and industrial process engineering, much broader ranges are of practical concern.

<span class="mw-page-title-main">Sustainable architecture</span> Architecture designed to minimize environmental impact

Sustainable architecture is architecture that seeks to minimize the negative environmental impact of buildings through improved efficiency and moderation in the use of materials, energy, development space and the ecosystem at large. Sustainable architecture uses a conscious approach to energy and ecological conservation in the design of the built environment.

<span class="mw-page-title-main">Superinsulation</span> Method of insulating a building

Superinsulation is an approach to building design, construction, and retrofitting that dramatically reduces heat loss by using much higher insulation levels and airtightness than average. Superinsulation is one of the ancestors of the passive house approach.

<span class="mw-page-title-main">Zero-energy building</span> Energy efficiency standard for buildings

A Zero-Energy Building (ZEB), also known as a Net Zero-Energy (NZE) building, is a building with net zero energy consumption, meaning the total amount of energy used by the building on an annual basis is equal to the amount of renewable energy created on the site or in other definitions by renewable energy sources offsite, using technology such as heat pumps, high efficiency windows and insulation, and solar panels.

Renewable heat is an application of renewable energy referring to the generation of heat from renewable sources; for example, feeding radiators with water warmed by focused solar radiation rather than by a fossil fuel boiler. Renewable heat technologies include renewable biofuels, solar heating, geothermal heating, heat pumps and heat exchangers. Insulation is almost always an important factor in how renewable heating is implemented.

<span class="mw-page-title-main">Building insulation</span> Material to reduce heat transfer in structures

Building insulation is material used in a building to reduce the flow of thermal energy. While the majority of insulation in buildings is for thermal purposes, the term also applies to acoustic insulation, fire insulation, and impact insulation. Often an insulation material will be chosen for its ability to perform several of these functions at once.

<span class="mw-page-title-main">Photovoltaic thermal hybrid solar collector</span>

Photovoltaic thermal collectors, typically abbreviated as PVT collectors and also known as hybrid solar collectors, photovoltaic thermal solar collectors, PV/T collectors or solar cogeneration systems, are power generation technologies that convert solar radiation into usable thermal and electrical energy. PVT collectors combine photovoltaic solar cells, which convert sunlight into electricity, with a solar thermal collector, which transfers the otherwise unused waste heat from the PV module to a heat transfer fluid. By combining electricity and heat generation within the same component, these technologies can reach a higher overall efficiency than solar photovoltaic (PV) or solar thermal (T) alone.

<span class="mw-page-title-main">Solar air heat</span> Solar thermal technology

Solar air heating is a solar thermal technology in which the energy from the sun, insolation, is captured by an absorbing medium and used to heat air. Solar air heating is a renewable energy heating technology used to heat or condition air for buildings or process heat applications. It is typically the most cost-effective out of all the solar technologies, especially in commercial and industrial applications, and it addresses the largest usage of building energy in heating climates, which is space heating and industrial process heating.

<span class="mw-page-title-main">Insulated glazing</span> Construction element consisting of at least two glass plates

Insulating glass (IG) consists of two or more glass window panes separated by a space to reduce heat transfer across a part of the building envelope. A window with insulating glass is commonly known as double glazing or a double-paned window, triple glazing or a triple-paned window, or quadruple glazing or a quadruple-paned window, depending upon how many panes of glass are used in its construction.

Zero-carbon housing is a term used to describe a house that does not emit greenhouse gasses, specifically carbon dioxide (CO2), into the atmosphere. Homes release greenhouse gases through burning fossil fuels in order to provide heat, or even while cooking on a gas stove. A zero carbon house can be achieved by either building or renovating a home to be very energy efficient and for its energy consumption to be from non-emitting sources, for example electricity.

<span class="mw-page-title-main">Skylight</span> Window in the ceiling-roof

A skylight is a light-permitting structure or window, usually made of transparent or translucent glass, that forms all or part of the roof space of a building for daylighting and ventilation purposes.

Sustainable refurbishment describes working on existing buildings to improve their environmental performance using sustainable methods and materials. A refurbishment or retrofit is defined as: "any work to a building over and above maintenance to change its capacity, function or performance' in other words, any intervention to adjust, reuse, or upgrade a building to suit new conditions or requirements". Refurbishment can be done to a part of a building, an entire building, or a campus. Sustainable refurbishment takes this a step further to modify the existing building to perform better in terms of its environmental impact and its occupants' environment.

References

  1. 1 2 3 Schmidt, Charles W. (January 2008). "Bringing Green Homes within Reach: Healthier Housing for More People". Environmental Health Perspectives. 116 (1): A24–A31. doi:10.1289/ehp.116-a24. ISSN   0091-6765. PMC   2199308 . PMID   18197286.
  2. 1 2 3 4 5 6 7 8 9 10 11 12 "What is an eco-house". The Living Village Trust.
  3. "Why not build houses the environmentally friendly way? Better for nature, better for business: How a green building influences the health of its occupants". ScienceDaily. Retrieved 2020-03-31.
  4. Pickerill, Jenny (2017). "Critically Interrogating Eco-Homes". International Journal of Urban and Regional Research. 41 (2): 353–365. doi: 10.1111/1468-2427.12453 . ISSN   1468-2427.

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