Төмен энергиялы үйлер: тұрақты архитектура және үнемділік

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). Buildings alone were responsible for 38% of all human Greenhouse gas emissions (GHG) as of 2008, with 20% attributed to residential buildings and 18% to commercial buildings. According to the Intergovernmental Panel on Climate Change (IPCC), buildings is the sector which presents the most cost effective opportunities for GHG reductions.

During the 1970s, research on low energy buildings was done in Denmark, Sweden, Germany, Canada, and the United States. The implementation of standardized low energy building concepts has developed differently in each country.

In the late 1970s, the province of Saskatchewan contracted the Saskatchewan Research Council to design and build a passive solar house suitable for the extreme climate of the Canadian prairies, where winter temperatures can drop to negative 40 degrees Celsius ( 40°F). The project resulted in the construction of the Saskatchewan Conservation House in Regina in 1977 by a team led by engineer Harold Orr. The project developed a heat recovery air exchanger (HRV), hot water recovery, and a blower door apparatus to measure building air tightness, techniques that became common in low energy building in other parts of the world. Orr would go on to apply many of those techniques to retro fitting existing buildings to improve energy efficiency.

Triggered in the 1970s by the first energy crisis and growing environmental awareness, energy conservation became increasingly important in Germany. In 1977, the country's first energy related building standard was enacted. The German Passivhaus Institute introduced the first certified passive house in 1990. The annual heating requirement was introduced as an important parameter by the third German Thermal Insulation Ordinance (1995). In 2013, however, there was no clear legal requirement for a low energy building standard in Germany. According to Maria Panagiotidou and Robert J. Fuller, definitions, policies and construction activity of zero energy buildings must be clear. The European Union's Energy Performance Directive requires that beginning in 2021, only low energy buildings may be built.

Changes to national policies have occurred since May 2015 in the UK. One of the most significant has been the withdrawal of the Code for Sustainable Homes (CfSH) as a system for assessing and encouraging improvements in the environmental design of dwellings. This has abandoned the code's schematic which provided a framework of achievement levels and to which low energy designers could aspire to meet or surpass. Although energy conservation legislation still exists in the building regulations, there is a lack of suitable standards exceeding basic regulations. As a result, the Passive House Standard may expand its influence and impact on energy efficient houses.

Interest in low energy buildings has increased in the United States, primarily due to rising energy prices, decreasing costs for onsite renewable energy systems, and increasing concern about climate change. California requires all new residential construction to be zero net energy by 2020. These standards sometimes seek to limit the energy used for space heating, which is the largest energy consumer in many climate zones. Other energy uses may also be regulated. The history of passive solar building design provides an international view of one form of low energy building development and standards.

Standards for low energy buildings in Europe have proceeded differently in each country, and there is no common certification or legislation for low energy buildings valid in all EU member states. As a movement towards reducing energy use and emissions, a common legislation concerning buildings’ energy performance, the Energy Performance of Buildings Directive (EPBD) was published in 2002 and became effective in January 2003.

Low energy houses are defined in the National Building Regulation Building Regulations 08, and are divided into two classes. They are regulated in the regulations' chapter 7.2.4: Low energy.

Low energy houses certified by RAL GZ 965 have 30 percent less heat losses than regulated in the EnEV, a national building code. Other criteria affect insulation, air tightness and ventilation. Low energy buildings may be certified by RAL GZ 965 for planning or construction.

Low energy buildings may receive the Minergie certification, a "quality label for new and refurbished buildings". The Minergie standard requires that buildings do not exceed 75 percent of average building energy consumption and fossil fuel consumption must not exceed 50 percent of the average.

Reduction of energy consumption is more environmentally and financially advantageous than increasing onsite production to reach a low energy goal. The less a home consumes, the smaller renewable energy system it requires to reach net zero. Energy efficiency should always be the primary design strategy of a low energy house. Other techniques to reduce excess solar heat include brise soleils, trees, attached pergolas with vines, vertical gardens, and green roofs. Although low energy houses can be constructed from dense or lightweight materials, internal thermal mass is normally incorporated to reduce summer peak temperatures, maintain stable winter temperatures, and prevent possible overheating in spring or autumn before the higher sun angle "shades" midday wall exposure and window penetration. Exterior wall color (when the surface allows choice) reflection or absorption depends on the predominant year round outdoor temperature. The use of deciduous trees and wall trellised (or self attaching) vines can assist in temperate climates.

To minimize total primary energy consumption, passive and active daylighting are the first daytime solutions to employ. For low light days, non daylight spaces and nighttime, sustainable lighting design with low energy sources (such as standard voltage compact fluorescent lamps and solid state lighting with LED lamps, OLEDs and polymer light emitting diodes and low voltage incandescent light bulbs, compact metal halide, xenon and halogen lamps) can be used. Solar powered exterior security and landscape lighting, with solar cells on each fixture or connecting to a central solar panel, are available for gardens and outdoor needs. Low voltage systems can be used for more controlled (or independent) illumination, using less electricity than conventional fixtures and lamps. Timers, motion detection and daylighting operation sensors further reduce energy consumption and light pollution. Home appliances meeting independent energy efficiency testing and receiving Ecolabel certification marks for reduced electrical and natural gas consumption and product manufacturing carbon emission labels are preferred for low energy houses. Energy Star and EKOenergy are other certification marks.