Passivhaus Darmstadt Kranichstein Fruehling 2006

"Passive house" (german: Passivhaus) is a voluntary standard for

energy efficiency Energy efficiency may refer to: * Energy efficiency (physics), the ratio between the useful output and input of an energy conversion process ** Electrical efficiency, useful power output per electrical power consumed ** Mechanical efficiency, a ra ...

in a

building A building, or edifice, is an enclosed structure with a roof and walls standing more or less permanently in one place, such as a house or factory (although there's also portable buildings). Buildings come in a variety of sizes, shapes, and fu ...

, 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 building An office is a space where an organization's employees perform administrative work in order to support and realize objects and goals of the organization. The word "office" may also denote a position within an organization with specific dut ...

school A school is an educational institution designed to provide learning spaces and learning environments for the teaching of students under the direction of teachers. Most countries have systems of formal education, which is sometimes comp ...

kindergarten Kindergarten is a preschool educational approach based on playing, singing, practical activities such as drawing, and social interaction as part of the transition from home to school. Such institutions were originally made in the late 18th ce ...

s 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. In 2008, estimates of the number of passive house buildings around the world ranged from 15,000 to 20,000 structures. In 2016, there were approximately 60,000 such certified structures of all types worldwide. The vast majority of passive structures have been built in German-speaking countries and

Scandinavia Scandinavia; Sámi languages: /. ( ) is a subregion in Northern Europe, with strong historical, cultural, and linguistic ties between its constituent peoples. In English usage, ''Scandinavia'' most commonly refers to Denmark, Norway, and Swe ...

History

The ''passivhaus'' standard originated from a conversation in May 1988 between Bo Adamson of

Lund University , motto = Ad utrumque , mottoeng = Prepared for both , established = , type = Public research university , budget = SEK 9 billion Sweden, and Wolfgang Feist of the ''Institut für Wohnen und Umwelt'' (Institute for Housing and the Environment), in Darmstadt,

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...

. Later, their concept was further developed through a number of

research project Research is "creative and systematic work undertaken to increase the stock of knowledge". It involves the collection, organization and analysis of evidence to increase understanding of a topic, characterized by a particular attentiveness t ...

s, aided by financial assistance from the German state of

Hessen Hesse (, , ) or Hessia (, ; german: Hessen ), officially the State of Hessen (german: links=no, Land Hessen), is a state in Germany. Its capital city is Wiesbaden, and the largest urban area is Frankfurt. Two other major historic cities are Darms ...

. Much of the early "passive houses" builds were based on research and the experience of North American builders during the 1970s, who – in response to the oil embargo – sought to build homes that used very little to no energy. These designs often utilized expansive solar-gain windows, which used the sun as a heat source. However, superinsulation prevailed over, as seen in the Saskatchewan Conservation House (1977) and the Leger House in Pepperell, Massachusetts (1977). The Saskatchewan Conservation house was a project of the

Saskatchewan Research Council The Saskatchewan Research Council (SRC) is a provincial treasury board crown corporation engaged in research and technology development on behalf of the provincial government and private industry. It focuses on applied research and development pr ...

(SRC), who independently developed a heat recovery air exchanger (HRV), hot water recovery, and a blower-door apparatus to measure building air-tightness — notably the house was designed for the extreme -40C to +40C climate of the Canadian prairie. The SRC and Leger houses were predated by the Lyngby, Denmark house (1975), developed by the

Technical University of Denmark The Technical University of Denmark ( da, Danmarks Tekniske Universitet), often simply referred to as DTU, is a polytechnic university and school of engineering. It was founded in 1829 at the initiative of Hans Christian Ørsted as Denmark's fir ...

, and several homes were built between 1977 and 1979 based on the Lo-Cal house design (1976) developed by the

University of Illinois at Urbana–Champaign The University of Illinois Urbana-Champaign (U of I, Illinois, University of Illinois, or UIUC) is a public land-grant research university in Illinois in the twin cities of Champaign and Urbana. It is the flagship institution of the Univer ...

. The name 'passive' can be partly attributed to

William Shurcliff William Asahel Shurcliff (March 27, 1909 – June 20, 2006) was an American physicist. Biography He received his BA cum laude in 1930, a PhD in Physics in 1934, and a degree in Business Administration in 1935, all from Harvard University. In the 1 ...

, an American physicist who contributed to the WWII Manhattan Project, and in the 1970s became an advocate for energy-efficient home design:

''"What name should be given to this new system? Superinsulated passive? Super-save passive? Mini-need passive? Micro-load passive? I lean toward ‘micro-load passive.’ Whatever it is called, it has (I predict) a big future." - William Shurcliff, 1979''

An early book explaining the concepts of passive house construction was ''The Passive Solar Energy Book'' by Edward Mazria in 1979.

First examples

The eventual construction of four row houses (terraced houses or town homes) were designed for four private clients by the architectural firm Bott, Ridder and Westermeyer. The first ''Passivhaus''

residences A residence is a place (normally a building) used as a home or dwelling, where people reside. Residence may more specifically refer to: * Domicile (law), a legal term for residence * Habitual residence, a civil law term dealing with the stat ...

were built in Darmstadt in 1990, and occupied by the clients the following year.

Further implementation and councils

In September 1996, the

Passivhaus-Institut The Passivhaus-Institut (PHI) is responsible for promoting and maintaining the Passivhaus building program. The ''"Passivhaus Institute"'' was founded in 1996, and is based and active in Darmstadt, Germany. The English spelling was used for the ...

was founded in Darmstadt to promote and control ''passivhaus'' standards. By 2010 more than 25,000 ''passivhaus'' structures were estimated to have been built. Most are located in Germany and

Austria Austria, , bar, Östareich officially the Republic of Austria, is a country in the southern part of Central Europe, lying in the Eastern Alps. It is a federation of nine states, one of which is the capital, Vienna, the most populous ...

, others in various countries worldwide. In 1996, after the concept had been validated at the Institute in Darmstadt, with space heating at 90% less than that required for a standard new building at the time, the Economical Passive Houses Working Group was created. This group developed the planning package and initiated the production of the innovative components that had been used, notably the windows and the high-efficiency ventilation systems. Meanwhile, further passive houses were built in Stuttgart (1993), Naumburg, Hesse,

Wiesbaden Wiesbaden () is a city in central western Germany and the capital of the state of Hesse. , it had 290,955 inhabitants, plus approximately 21,000 United States citizens (mostly associated with the United States Army). The Wiesbaden urban area ...

, and

Cologne Cologne ( ; german: Köln ; ksh, Kölle ) is the largest city of the German western state of North Rhine-Westphalia (NRW) and the fourth-most populous city of Germany with 1.1 million inhabitants in the city proper and 3.6 millio ...

(1997). Products that had been developed according to the ''passivhaus'' standard were further commercialized during and following the

European Union The European Union (EU) is a supranational political and economic union of member states that are located primarily in Europe. The union has a total area of and an estimated total population of about 447million. The EU has often been de ...

sponsored CEPHEUS project, which proved the concept in five European countries in the winter of 2000–2001. The first certified house was built in 2006 near

Bemidji, Minnesota Bemidji ( ) is a city and the county seat of Beltrami County, in northern Minnesota, United States. The population was 14,574 at the 2020 census. According to 2021 census estimates, the city is estimated to have a population of 15,279, making i ...

, in Camp Waldsee of the German

Concordia Language Villages Concordia Language Villages (CLV), previously the International Language Villages, is a world-language and culture education program. Since beginning in 1961, it has grown to offer summer camp in 15 modern languages and school-year weekend progr ...

. The first US passive retrofit project, the remodeled craftsman O'Neill house in

Sonoma, California Sonoma is a city in Sonoma County, California, United States, located in the North Bay region of the San Francisco Bay Area. Sonoma is one of the principal cities of California's Wine Country and the center of the Sonoma Valley AVA. Sonoma's p ...

, was certified in July 2010. In the United States, the concept of ''passivhaus'' design was first implemented by Katrin Klingenberg in 2003 when she built a passive home prototype named "The Smith House" in

Urbana, Illinois Urbana ( ) is a city in and the county seat of Champaign County, Illinois, United States. As of the 2020 census, Urbana had a population of 38,336. As of the 2010 United States Census, Urbana is the 38th-most populous municipality in Illinois. It ...

. Consequently, she and builder Mike Kernagis co-founded the Ecological Construction Laboratory (E-Colab) in 2004 to further explore the feasibility of the affordable passive design. It eventually led to the inception of the Passive House Institute United States (PHIUS) in 2007. Afterwards, the PHIUS has released their PHIUS + 2015 Building Standard and has certified over 1,200 projects and across the United States. In 2019, Park Avenue Green, a low-income housing building in New York was built with ''passivhaus'' standard. The building later became the largest certified "passive house" in North America. Ireland's first "passive house" was built in 2005 by Tomas O'Leary, a "passive house" designer and teacher. The house was called 'Out of the Blue'. Upon completion, Tomas moved into the building. The world's first standardised passive

prefabricated house Prefabricated homes, often referred to as prefab homes or simply prefabs, are specialist dwelling types of prefabricated building, which are manufactured off-site in advance, usually in standard sections that can be easily shipped and assembled. ...

was built in

Ireland Ireland ( ; ga, Éire ; Ulster Scots dialect, Ulster-Scots: ) is an island in the Atlantic Ocean, North Atlantic Ocean, in Northwestern Europe, north-western Europe. It is separated from Great Britain to its east by the North Channel (Grea ...

in 2005 by Scandinavian Homes a Swedish company, that has since built more passive houses in

England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe b ...

and

Poland Poland, officially the Republic of Poland, is a country in Central Europe. It is divided into 16 administrative provinces called voivodeships, covering an area of . Poland has a population of over 38 million and is the fifth-most populou ...

. The first certified "passive house" in the Antwerp region of

Belgium Belgium, ; french: Belgique ; german: Belgien officially the Kingdom of Belgium, is a country in Northwestern Europe. The country is bordered by the Netherlands to the north, Germany to the east, Luxembourg to the southeast, France to th ...

was built in 2010. In 2011, the city of

Heidelberg Heidelberg (; Palatine German language, Palatine German: ''Heidlberg'') is a city in the States of Germany, German state of Baden-Württemberg, situated on the river Neckar in south-west Germany. As of the 2016 census, its population was 159,914 ...

in Germany initiated the Bahnstadt project, which was seen as the world's largest passive house building area. A company in Qatar planned the country's first Passive House in 2013, the first in the region. The world's tallest "passive house" was built in the Bolueta neighborhood in

Bilbao ) , motto = , image_map = , mapsize = 275 px , map_caption = Interactive map outlining Bilbao , pushpin_map = Spain Basque Country#Spain#Europe , pushpin_map_caption ...

Spain , image_flag = Bandera de España.svg , image_coat = Escudo de España (mazonado).svg , national_motto = ''Plus ultra'' (Latin)(English: "Further Beyond") , national_anthem = (English: "Royal March") , i ...

. At , it is currently the world's tallest building certified under the standard in 2018. The $14.5 million, 171-unit development (including a nine-story companion to the high-rise) consists entirely of social housing. Gaobeidian, China hosted the 23rd International Passive House Conference in 2019, and later built Gaobeidian Railway City apartment complex which is reported to be "the world's largest passive house project". China have taken a leadership role in passive house construction, with 73 different companies "making windows to the 'passive house' standards." The United Kingdom’s first ''passivhaus''

health centre A healthcare center, health center, or community health center is one of a network of clinics staffed by a group of general practitioners and nurses providing healthcare services to people in a certain area. Typical services covered are family pr ...

, in

Foleshill Foleshill is a suburb in the north of Coventry in the West Midlands of England. Longford, Courthouse Green and Rowley Green are to its north and Keresley is to its west. The population of the Ward at the 2011 census was 19,943. History Fole ...

was opened in November 2021.

Standards

Passivhaus thermogram gedaemmt ungedaemmt

While some techniques and technologies were specifically developed for the "passive house" standard, others, such as superinsulation, already existed, and the concept of

passive solar building design 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, unli ...

dates back to antiquity. There were other previous buildings with

low-energy building 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 ...

standards, notably the German ''Niedrigenergiehaus'' (low-energy house) standard, in addition to buildings constructed to the demanding energy codes of Sweden and

Denmark ) , song = ( en, "King Christian stood by the lofty mast") , song_type = National and royal anthem , image_map = EU-Denmark.svg , map_caption = , subdivision_type = Sovereign state , subdivision_name = Kingdom of Denmark , establish ...

International Passivhaus Standard

The ''passivhaus'' standard requires that the building fulfills the following requirements: * Use up to of floor area per year for heating and cooling as calculated by the Passivhaus Planning Package, or a peak heat load of of floor area, based on local climate data. * Use up to of floor area per year

primary energy Primary energy (PE) is an energy form found in nature that has not been subjected to any human engineered conversion process. It is energy contained in raw fuels, and other forms of energy, including waste, received as input to a system. Prim ...

(for

heating A central heating system provides warmth to a number of spaces within a building from one main source of heat. It is a component of heating, ventilation, and air conditioning (short: HVAC) systems, which can both cool and warm interior spaces. ...

, hot water and

electricity Electricity is the set of physical phenomena associated with the presence and motion of matter that has a property of electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as describ ...

). * Leak air up to 0.6 times the house volume per hour (''n''₅₀ ≤ 0.6 / hour) at as tested by a

blower door A blower door is a machine used to measure the airtightness of buildings. It can also be used to measure airflow between building zones, to test ductwork airtightness and to help physically locate air leakage sites in the building envelope. Ther ...

; or up to per square foot of the surface area of the enclosure.

Recommendations

The specific heat load for the heating source at design temperature is recommended, but not required, to be less than 10 W/m² (3.17

btu The British thermal unit (BTU or Btu) is a unit of heat; it is defined as the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit. It is also part of the United States customary units. The modern SI u ...

/(h⋅ft²)). These standards are much higher than houses built to most normal building codes. For comparisons, see the international comparisons section below. National partners within the 'consortium for the Promotion of European Passive Houses' are thought to have some flexibility to adapt these limits locally.

Space heating requirement

If a building meets the ''passivhaus'' standards, it does not need conventional heating systems, though some heating will still be required and most ''passivhaus'' buildings include supplemental space heating. This is normally distributed through the low-volume

heat recovery ventilation Heat recovery ventilation (HRV), also known as mechanical ventilation heat recovery (MVHR), is an energy recovery ventilation system which works between two air sources at different temperatures. Heat recovery is a method which is used to reduce ...

system that is required to maintain air quality, rather than by a conventional hydronic or high-volume

forced-air A forced-air central heating system is one which uses air as its heat transfer medium. These systems rely on ductwork, vents, and plenums as means of air distribution, separate from the actual heating and air conditioning systems. The return ...

heating system, as described in the

space heating Heating, ventilation, and air conditioning (HVAC) is the use of various technologies to control the temperature, humidity, and purity of the air in an enclosed space. Its goal is to provide thermal comfort and acceptable indoor air quality. HV ...

section below.

Passive House standards in the US - Passive House Standard and PHIUS+

In the US there are two versions of "passive house" being promoted by two separate entities: the Passive House Institute (PHI) and the Passive House Institute US (PHIUS). PHIUS was originally an affiliate and approved trainer and certifier for the Passive House Institute. In 2011, PHI cancelled its contract with PHIUS for misconduct. PHIUS disputed the claims by PHI and continued working to launch an independent building performance program. In 2015 PHIUS launched its own "PHIUS+" standard. The PHIUS + 2015 Standard primarily focuses on reducing negative effects of building operations, for any type of building. This standard also uses climate data sets to determine specific

building performance Building performance is an attribute of a building that expresses how well that building carries out its functions. It may also relate to the performance of the building construction process. Categories of building performance are quality (how well ...

criteria for different regions. Such information is determined using metrics that represent a space where significant

carbon Carbon () is a chemical element with the symbol C and atomic number 6. It is nonmetallic and tetravalent—its atom making four electrons available to form covalent chemical bonds. It belongs to group 14 of the periodic table. Carbon mak ...

and energy reduction overlap with cost-effectiveness. Overall, the PHIUS database includes more than 1000

climate Climate is the long-term weather pattern in an area, typically averaged over 30 years. More rigorously, it is the mean and variability of meteorological variables over a time spanning from months to millions of years. Some of the meteorologi ...

data sets for North America. The Institute believes that this approach to the Standard is essential, as North America has variety of different climates and different passive measures may be more effective than others. The standard is based on five principles: airtightness,

ventilation Ventilation may refer to: * Ventilation (physiology), the movement of air between the environment and the lungs via inhalation and exhalation ** Mechanical ventilation, in medicine, using artificial methods to assist breathing *** Ventilator, a m ...

waterproofing Waterproofing is the process of making an object or structure waterproof or water-resistant so that it remains relatively unaffected by water or resisting the ingress of water under specified conditions. Such items may be used in wet environme ...

, heating and cooling, and electrical loads. Within these principles, projects must pass building specified blower door, ventilation airflow, overall airflow, and

electrical load An electrical load is an electrical component or portion of a circuit that consumes (active) electric power, such as electrical appliances and lights inside the home. The term may also refer to the power consumed by a circuit. This is opposed ...

tests; buildings must also achieve other measures such as low-emission materials, renewable energy systems, moisture control, outdoor ventilation, and energy efficient ventilation and space conditioning equipment. All buildings must also pass a quality assurance and quality control test – this is implemented to ensure that the building continues to adhere to the regional criteria set forth by the PHIUS’ climate data. These tests and analyses of operative conditions are performed by PHIUS raters or verifiers. These are accredited professionals from the PHIUS that are able to perform on-site testing and inspections to ensure that the newly constructed building is adhering to the construction plans, created energy models, and desired operating conditions. The two standards ("passive house" and PHIUS+) are distinct and target different performance metrics and use different energy modeling software and protocols. In the US, the International Passive House Standard is supported by the North American Passive House Network (NAPHN) and its chapters, as well as by independent affiliates such as Passive House California and New York Passive House.

Construction costs

In ''passivhaus'' buildings, the cost savings from dispensing with the conventional heating system can be used to fund the upgrade of the building envelope and the heat recovery ventilation system. With careful design and increasing competition in the supply of the specifically designed ''passivhaus'' building products, in Germany it is currently possible to construct buildings for the same cost as those built to normal German

building standards A building code (also building control or building regulations) is a set of rules that specify the standards for constructed objects such as buildings and non-building structures. Buildings must conform to the code to obtain planning permissi ...

, as was done with the ''passivhaus'' apartments at

Vauban, Freiburg Vauban () is a neighbourhood (''Stadtteil'') to the south of the town centre in Freiburg, Germany. It was built as "a sustainable model district" on the site of a former French military base named after Sébastien Le Prestre de Vauban, the 17th c ...

. On average passive houses are reported to be more expensive upfront than conventional buildings – 5% to 8% in Germany, 8% to 10% in UK and 5% to 10% in USA. Evaluations have indicated that while it is technically possible, the costs of meeting the ''passivhaus'' standard increase significantly when building in Northern Europe above 60° latitude. European cities at approximately 60° include

Helsinki Helsinki ( or ; ; sv, Helsingfors, ) is the capital, primate, and most populous city of Finland. Located on the shore of the Gulf of Finland, it is the seat of the region of Uusimaa in southern Finland, and has a population of . The city ...

in Finland and

Bergen Bergen (), historically Bjørgvin, is a city and municipality in Vestland county on the west coast of Norway. , its population is roughly 285,900. Bergen is the second-largest city in Norway. The municipality covers and is on the peninsula o ...

in Norway.

London London is the capital and List of urban areas in the United Kingdom, largest city of England and the United Kingdom, with a population of just under 9 million. It stands on the River Thames in south-east England at the head of a estuary dow ...

is at 51°;

Moscow Moscow ( , US chiefly ; rus, links=no, Москва, r=Moskva, p=mɐskˈva, a=Москва.ogg) is the capital and largest city of Russia. The city stands on the Moskva River in Central Russia, with a population estimated at 13.0 millio ...

is at 55°.

Design and construction

Achieving the major decrease in heating energy consumption required by the standard involves a shift in approach to building design and construction. Design may be assisted by use of the 'Passivhaus Planning Package' (PHPP), which uses specifically designed computer simulations. Below are the techniques used to achieve the standard.

Passive solar design and landscape

Passive solar building design 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, unli ...

and

energy-efficient landscaping Energy-efficient landscaping is a type of landscaping designed for the purpose of conserving energy. There is a distinction between the embedded energy of materials and constructing the landscape, and the energy consumed by the maintenance and ope ...

support the passive house energy conservation and can integrate them into a neighborhood and environment. Following passive solar building techniques, where possible buildings are compact in shape to reduce their surface area, with principal windows oriented towards the equator – south in the northern hemisphere and north in the southern hemisphere – to maximize passive

solar gain Solar gain (also known as solar heat gain or passive solar gain) is the increase in thermal energy of a space, object or structure as it absorbs incident solar radiation. The amount of solar gain a space experiences is a function of the total in ...

. However, the use of solar gain, especially in

temperate In geography, the temperate climates of Earth occur in the middle latitudes (23.5° to 66.5° N/S of Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ranges throughout ...

regions, is secondary to minimizing the overall house energy requirements. In climates and regions needing to reduce excessive summer passive solar heat gain, whether from direct or reflected sources, '' brise soleil'',

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are ...

s, attached '' pergolas'' with

vine A vine (Latin ''vīnea'' "grapevine", "vineyard", from ''vīnum'' "wine") is any plant with a growth habit of trailing or scandent (that is, climbing) stems, lianas or runners. The word ''vine'' can also refer to such stems or runners themsel ...

s, vertical gardens,

green roof A green roof or living roof is a roof of a building that is partially or completely covered with vegetation and a growing medium, planted over a waterproofing membrane. It may also include additional layers such as a root barrier and drainage ...

s, and other techniques are implemented. Exterior wall color, when the surface allows choice, for reflection or absorption insolation qualities depends on the predominant year-round ambient outdoor temperature. The use of

deciduous In the fields of horticulture and Botany, the term ''deciduous'' () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, ...

trees and wall trellised or self attaching vines can assist in climates not at the temperature extremes.

Superinsulation

''Passivhaus'' buildings employ superinsulation to significantly reduce the heat transfer through the walls, roof and floor compared to conventional buildings. A wide range of

thermal insulation Thermal insulation is the reduction of heat transfer (i.e., the transfer of thermal energy between objects of differing temperature) between objects in thermal contact or in range of radiative influence. Thermal insulation can be achieved with ...

materials can be used to provide the required high R-values (low

U-value In the context of construction, the R-value is a measure of how well a two-dimensional barrier, such as a layer of insulation, a window or a complete wall or ceiling, resists the conductive flow of heat. R-value is the temperature difference pe ...

s, typically in the 0.10 to 0.15 W/(m²·K) range). Special attention is given to eliminating

thermal bridge A thermal bridge, also called a cold bridge, heat bridge, or thermal bypass, is an area or component of an object which has higher thermal conductivity than the surrounding materials, creating a path of least resistance for heat transfer.Gorse, Chr ...

s. A disadvantage resulting from the thickness of wall insulation required is that, unless the external dimensions of the building can be enlarged to compensate, the internal floor area of the building may be less compared to traditional construction. In Sweden, to achieve passive house standards, the insulation thickness would be (0.10 W/(m²·K)) and the roof (U-value 0.066 W/(m²·K)).

Advanced window technology

To meet the requirements of the ''passivhaus'' standard, windows are manufactured with exceptionally high R-values (low U-values, typically 0.85 to 0.45 W/(m²·K) for the entire window including the frame). The windows normally combine triple or

quadruple Quadruple may refer to: * 4-tuple, an ordered list of elements, with four elements * Quad (figure skating), a figure skating jump * Quadruple (computing), a term used as alternative for nibble in some contexts * Quadruple-precision floating-point ...

-pane

insulated glazing 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, ...

(with an appropriate solar heat-gain coefficient,

low-emissivity Low emissivity (low ''e'' or low thermal 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 co ...

coatings, sealed

argon Argon is a chemical element with the symbol Ar and atomic number 18. It is in group 18 of the periodic table and is a noble gas. Argon is the third-most abundant gas in Earth's atmosphere, at 0.934% (9340 ppmv). It is more than twice as ...

krypton Krypton (from grc, κρυπτός, translit=kryptos 'the hidden one') is a chemical element with the symbol Kr and atomic number 36. It is a colorless, odorless, tasteless noble gas that occurs in trace amounts in the atmosphere and is often ...

gas filled inter-pane voids, and 'warm edge' insulating glass spacers) with air-seals and specially developed thermal break window frames. In

Central Europe Central Europe is an area of Europe between Western Europe and Eastern Europe, based on a common historical, social and cultural identity. The Thirty Years' War (1618–1648) between Catholicism and Protestantism significantly shaped the a ...

and most of the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...

, for unobstructed south-facing ''passivhaus'' windows, the heat gains from the sun are, on average, greater than the heat losses, even in mid-winter.

Airtightness

Building envelopes under the ''passivhaus'' standard are required to be extremely

airtight A hermetic seal is any type of sealing that makes a given object airtight (preventing the passage of air, oxygen, or other gases). The term originally applied to airtight glass containers, but as technology advanced it applied to a larger categor ...

compared to conventional construction. They are required to meet either 0.60 ACH50 (air changes per hour at 50 pascals) based on the building's volume, or 0.05 CFM50/sf (cubic feet per minute at 50 pascals, per square foot of building enclosure surface area). In order to achieve these metrics, recommended best practice is to test the building air barrier enclosure with a

at mid-construction if possible. "Passive house" is designed so that most of the air exchange with exterior is done by controlled ventilation through a

heat-exchanger A heat exchanger is a system used to transfer heat between a source and a working fluid. Heat exchangers are used in both cooling and heating processes. The fluids may be separated by a solid wall to prevent mixing or they may be in direct contac ...

in order to minimize heat loss (or gain, depending on climate), so uncontrolled air leaks are best avoided. Another reason is the passive house standard makes extensive use of insulation which usually requires a careful management of

moisture Moisture is the presence of a liquid, especially water, often in trace amounts. Small amounts of water may be found, for example, in the air (humidity), in foods, and in some commercial products. Moisture also refers to the amount of water vapo ...

and

dew point The dew point is the temperature to which air must be cooled to become saturated with water vapor, assuming constant air pressure and water content. When cooled below the dew point, moisture capacity is reduced and airborne water vapor will cond ...

s. This is achieved through air barriers, careful sealing of every construction joint in the building envelope, and sealing of all service penetrations.

Ventilation

Use of passive

natural ventilation Passive ventilation is the process of supplying air to and removing air from an indoor space without using mechanical systems. It refers to the flow of external air to an indoor space as a result of pressure differences arising from natural forces ...

is an integral component of passive house design where ambient temperature is conducive — either by singular or cross ventilation, by a simple opening or enhanced by the stack effect from smaller ingress with larger egress windows and/or clerestory-operable skylight. When ambient climate is not conducive, mechanical

systems, with a heat recovery rate of over 80% and high-efficiency

electronically commutated motor A brushless DC electric motor (BLDC motor or BL motor), also known as an electronically commutated motor (ECM or EC motor) or synchronous DC motor, is a synchronous motor using a direct current (DC) electric power supply. It uses an electronic ...

s (ECM), are employed to maintain air quality, and to recover sufficient heat to dispense with a conventional central heating system. Since passively designed buildings are essentially

air-tight A hermetic seal is any type of sealing that makes a given object airtight (preventing the passage of air, oxygen, or other gases). The term originally applied to airtight glass containers, but as technology advanced it applied to a larger categor ...

, the rate of air change can be optimized and carefully controlled at about 0.4

air changes per hour Air changes per hour, abbreviated ACPH or ACH, or air change rate is the number of times that the total air volume in a room or space is completely removed and replaced in an hour. If the air in the space is either uniform or perfectly mixed, air c ...

. All ventilation ducts are insulated and sealed against leakage. Some ''passivhaus'' builders promote the use of earth warming tubes. The tubes are typically around in diameter, long at a depth of about . They are buried in the soil to act as earth-to-air heat exchangers and pre-heat (or pre-cool) the intake air for the ventilation system. In cold weather, the warmed air also prevents

ice Ice is water frozen into a solid state, typically forming at or below temperatures of 0 degrees Celsius or Depending on the presence of impurities such as particles of soil or bubbles of air, it can appear transparent or a more or less opaqu ...

formation in the heat recovery system's

heat exchanger A heat exchanger is a system used to transfer heat between a source and a working fluid. Heat exchangers are used in both cooling and heating processes. The fluids may be separated by a solid wall to prevent mixing or they may be in direct conta ...

. Concerns about this technique have arisen in some climates due to problems with condensation and mold. Alternatively, an earth to air heat exchanger can use a liquid circuit instead of an air circuit, with a heat exchanger (battery) on the supply air.

Space heating

In addition to using passive

, ''passivhaus'' buildings make extensive use of their intrinsic heat from internal sources—such as waste heat from lighting,

white goods A major appliance, also known as a large domestic appliance or large electric appliance or simply a large appliance, large domestic, or large electric, is a non-portable or semi-portable machine used for routine housekeeping tasks such as cookin ...

(major appliances) and other electrical devices (but not dedicated heaters)—as well as body heat from the people and other animals inside the building. This is due to the fact that people, on average, emit heat equivalent to 100

watt The watt (symbol: W) is the unit of power or radiant flux in the International System of Units (SI), equal to 1 joule per second or 1 kg⋅m2⋅s−3. It is used to quantify the rate of energy transfer. The watt is named after James ...

s each of radiated thermal energy. Together with the comprehensive energy conservation measures taken, this means that a conventional

central heating A central heating system provides warmth to a number of spaces within a building from one main source of heat. It is a component of heating, ventilation, and air conditioning (short: HVAC) systems, which can both cool and warm interior spaces. ...

system is not necessary, although they are sometimes installed due to client's skepticism.Zeller, 2010. p.BU1. Example: in the case of the Landau home described in the NYT's article, several insurance companies refused to insure their home when they were told there was no home furnace in the structure, fearing that they would be held financially liable for frozen water pipe damage. Instead, "passive houses" sometimes have a dual purpose 800 to 1,500

heating and/or cooling element integrated with the supply air duct of the ventilation system, for use during the coldest days. It is fundamental to the design that all the heat required can be transported by the normal low air volume required for ventilation. A maximum air temperature of is applied, to prevent any possible smell of scorching from dust that escapes the filters in the system. The air-heating element can be heated by a small

heat pump A heat pump is a device that can heat a building (or part of a building) by transferring thermal energy from the outside using a refrigeration cycle. Many heat pumps can also operate in the opposite direction, cooling the building by removing ...

, by direct

solar thermal energy Solar thermal energy (STE) is a form of energy and a technology for harnessing solar energy to generate thermal energy for use in industry, and in the residential and commercial sectors. Solar thermal collectors are classified by the United St ...

annualized geothermal solar Seasonal thermal energy storage (STES), also known as inter-seasonal thermal energy storage, is the storage of heat or cold for periods of up to several months. The thermal energy can be collected whenever it is available and be used whenever nee ...

, or simply by a

natural gas Natural gas (also called fossil gas or simply gas) is a naturally occurring mixture of gaseous hydrocarbons consisting primarily of methane in addition to various smaller amounts of other higher alkanes. Low levels of trace gases like carbo ...

oil burner An oil burner is a heating device which burns #1, #2 and #6 heating oils, diesel fuel or other similar fuels. In the United States ultra low #2 diesel is the common fuel used. It is dyed red to show that it is road-tax exempt. In most markets ...

. In some cases a micro-heat pump is used to extract additional heat from the exhaust ventilation air, using it to heat either the incoming air or the

hot water storage tank A hot water storage tank (also called a hot water tank, thermal storage tank, hot water thermal storage unit, heat storage tank and hot water cylinder) is a water tank used for storing hot water for space heating or domestic use. Water is a con ...

. Small wood-burning stoves can also be used to heat the water tank, although care is required to ensure that the room in which stove is located does not overheat. Beyond the recovery of heat by the heat recovery ventilation unit, a well designed Passive house in the European climate should not need any supplemental heat source if the heating load is kept under 10 W/m². Because the heating capacity and the heating energy required by a passive house both are very low, the particular

energy source Energy development is the field of activities focused on obtaining sources of energy from natural resources. These activities include production of renewable, nuclear, and fossil fuel derived sources of energy, and for the recovery and reuse ...

selected has fewer financial implications than in a traditional building, although renewable energy sources are well suited to such low loads. The "passive house" standards in Europe set a space heating and cooling energy demand of per year, and peak demand. In addition, the total energy to be used in the building operations including heating, cooling, lighting, equipment, hot water, plug loads, etc. is limited to of treated floor area per year.

Lighting and electrical appliances

To minimize the total primary energy consumption, the many

passive Passive may refer to: * Passive voice, a grammatical voice common in many languages, see also Pseudopassive * Passive language, a language from which an interpreter works * Passivity (behavior), the condition of submitting to the influence of o ...

and active daylighting techniques are the first daytime solution to employ. For low-light days, non-daylighted spaces, and nighttime, the use of creative-sustainable

lighting design In theatre, a lighting designer (or LD) works with the director, choreographer, set designer, costume designer, and sound designer to create the lighting, atmosphere, and time of day for the production in response to the text while keeping i ...

using low-energy sources can be used. Low-energy sources include 'standard voltage'

compact fluorescent lamp A compact fluorescent lamp (CFL), also called compact fluorescent light, energy-saving light and compact fluorescent tube, is a fluorescent lamp designed to replace an incandescent light bulb; some types fit into light fixtures designed for inca ...

solid-state lighting Solid-state lighting (SSL) is a type of lighting that uses semiconductor light-emitting diodes (LEDs), organic light-emitting diodes (OLED), or polymer light-emitting diodes (PLED) as sources of illumination rather than electrical filaments, pl ...

with

LED lamp An LED lamp or LED light bulb is an electric light that produces light using light-emitting diodes (LEDs). LED lamps are significantly more energy-efficient than equivalent incandescent lamps and can be significantly more efficient than mo ...

organic light-emitting diode An organic light-emitting diode (OLED or organic LED), also known as organic electroluminescent (organic EL) diode, is a light-emitting diode (LED) in which the emissive electroluminescent layer is a film of organic compound that emits light i ...

s, PLED – polymer light-emitting diodes, 'low voltage'

electrical filament An incandescent light bulb, incandescent lamp or incandescent light globe is an electric light with a wire filament heated until it glows. The filament is enclosed in a glass bulb with a vacuum or inert gas to protect the filament from oxidat ...

Incandescent light bulb An incandescent light bulb, incandescent lamp or incandescent light globe is an electric light with a wire filament heated until it glows. The filament is enclosed in a glass bulb with a vacuum or inert gas to protect the filament from oxid ...

s, compact metal halide,

xenon Xenon is a chemical element with the symbol Xe and atomic number 54. It is a dense, colorless, odorless noble gas found in Earth's atmosphere in trace amounts. Although generally unreactive, it can undergo a few chemical reactions such as the ...

, and

halogen lamps A halogen lamp (also called tungsten halogen, quartz-halogen, and quartz iodine lamp) is an incandescent lamp consisting of a tungsten filament sealed in a compact transparent envelope that is filled with a mixture of an inert gas and a smal ...

. Solar powered exterior circulation, security, and

landscape lighting Landscape lighting or garden lighting refers to the use of outdoor illumination of private gardens and public landscapes; for the enhancement and purposes of safety, nighttime aesthetics, accessibility, security, recreation and sports, and s ...

– with

photovoltaic cell A solar cell, or photovoltaic cell, is an electronic device that converts the energy of light directly into electricity by the photovoltaic effect, which is a physical and chemical phenomenon.

s on each fixture or connecting to a central Solar panel system, are available for

garden A garden is a planned space, usually outdoors, set aside for the cultivation, display, and enjoyment of plants and other forms of nature. The single feature identifying even the wildest wild garden is ''control''. The garden can incorporate bot ...

s and outdoor needs. Low voltage systems can be used for more controlled or independent illumination, while still using less electricity than conventional fixtures and lamps. Timers, motion detection and

natural light Natural Light, sometimes Natty Light, is an American reduced-calorie light lager brewed by Anheuser-Busch since its introduction on July 31, 1977. Its ingredients are listed as water, barley malt, cereal grains, yeast, and hops. One serving c ...

operation sensors reduce energy consumption, and

light pollution Light pollution is the presence of unwanted, inappropriate, or excessive use of artificial Visible spectrum, lighting. In a descriptive sense, the term ''light pollution'' refers to the effects of any poorly implemented lighting, during the day ...

even further for a ''passivhaus'' setting. Appliance

consumer product A final good or consumer good is a final product ready for sale that is used by the consumer to satisfy current wants or needs, unlike a intermediate good, which is used to produce other goods. A microwave oven or a bicycle is a final good, but ...

s meeting independent energy efficiency testing and receiving Ecolabel

certification mark A certification mark (or conformity mark) on a commercial product indicates the existence of an accepted product standard or regulation and a claim that the manufacturer has verified compliance with those standards or regulations. The specifi ...

s for reduced electrical-'natural-gas' consumption, as well as product manufacturing

carbon emission label A carbon emission label or carbon label describes the carbon dioxide emissions created as a by-product of manufacturing, transporting, or disposing of a consumer product. This information is important to consumers wishing to minimize their ecologic ...

s are preferred for use in Passive houses. The eco-label certification marks of

Energy Star Energy Star (trademarked ''ENERGY STAR'') is a program run by the U.S. Environmental Protection Agency (EPA) and U.S. Department of Energy (DOE) that promotes energy efficiency. The program provides information on the energy consumption of pr ...

and

EKOenergy EKOenergy is an ecolabel for electricity. It is a not-for-profit initiative of the EKOenergy Network, a group of more than 40 environmental organizations from 30 countries. EKOenergy started in 2013 in Europe. Its secretariat is based in Helsinki. ...

are examples.

Traits of passive houses

Typically, passive houses feature: * Fresh, clean air: Note that for the parameters tested, and provided the filters (minimum F6) are maintained,

HEPA HEPA (, high-efficiency particulate air) filter, also known as high-efficiency particulate absorbing filter and high-efficiency particulate arrestance filter, is an efficiency standard of air filters. Filters meeting the HEPA standard must s ...

quality air is provided. 0.3 air changes per hour (ACH) are recommended, otherwise the air can become "stale" (excess CO₂, flushing of indoor air pollutants) and any greater, excessively dry (less than 40% humidity). This implies careful selection of interior finishes and furnishings, to minimize indoor air pollution from

VOC VOC, VoC or voc may refer to: Science and technology * Open-circuit voltage (VOC), the voltage between two terminals when there is no external load connected * Variant of concern, a category used during the assessment of a new variant of a virus ...

's (e.g.,

formaldehyde Formaldehyde ( , ) (systematic name methanal) is a naturally occurring organic compound with the formula and structure . The pure compound is a pungent, colourless gas that polymerises spontaneously into paraformaldehyde (refer to section ...

). This can be counteracted somewhat by opening a window for a very brief time, by plants, and by indoor fountains. * Because of the high resistance to heat flow (high R-value insulation), there are no "outside walls" which are colder than other walls. * Homogeneous interior temperature: it is impossible to have single rooms (e.g. the sleeping rooms) at a different temperature from the rest of the house. Note that the relatively high temperature of the sleeping areas is physiologically not considered desirable by some building scientists. Bedroom windows can be cracked open slightly to alleviate this when necessary. * Slow temperature changes: with ventilation and heating systems switched off, a passive house typically loses less than per day (in winter), stabilizing at around in the central European climate. * Quick return to normal temperature: opening windows or doors for a short time has only a limited effect; after apertures are closed, the air very quickly returns to the "normal" temperature. * Some have voiced concerns that ''passivhaus'' standard is not a general approach as the occupant has to behave in a prescribed way, for example not opening windows too often. However modelling shows that such concerns are not valid.

International comparisons

* In the

, a house built to the ''passivhaus'' standard results in a building that requires space heating energy of per

heating degree day Heating degree day (HDD) is a measurement designed to quantify the demand for energy needed to heat a building. HDD is derived from measurements of outside air temperature. The heating requirements for a given building at a specific location are ...

, compared with about per heating degree day for a similar building built to meet the 2003 Model Energy Efficiency Code. This is between 75 and 95% less energy for space heating and cooling than current new buildings that meet today's US energy efficiency codes. The passive house in the German-language camp of Waldsee, Minnesota, was designed under the guidance of architect Stephan Tanner of INTEP, LLC, a Minneapolis- and Munich-based consulting company for high performance and sustainable construction. Waldsee BioHaus is modeled on Germany's ''passivhaus'' standard, when compared to houses of the U.S. LEED standard, shows improvement to the quality of life inside the building while using 85% less energy than a house built to the latter standard. VOLKsHouse 1.0 was the first certified "passive house" offered and sold in Santa Fe New Mexico. * In the

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the European mainland, continental mainland. It comprises England, Scotlan ...

, an average new house built with the "passive house" standard would use 77% less energy for space heating, compared to the house built under circa-2006 Building Regulations. * In

, a typical house built to the "passive house" standard instead of the 2002 Building Regulations would consume 85% less energy for space heating and cut space-heating related carbon emissions by 94%.

Comparison with zero energy buildings

net zero Carbon neutrality is a state of net-zero carbon dioxide emissions. This can be achieved by balancing emissions of carbon dioxide with its removal (often through carbon offsetting) or by eliminating emissions from society (the transition to the " ...

-energy building (ZEB) is a building that over a year does not use more energy than it generates. The first 1979 Zero Energy Design building used passive solar heating and cooling techniques with airtight construction and super insulation. A few ZEBs fail to fully exploit more affordable conservation technology and all use onsite active renewable energy technologies like photovoltaic to offset the building's primary energy consumption. "Passive house" and ZEB are regarded as complementary synergistic technology approaches, based on the same physics of thermal energy transfer and storage: ZEBs drive the annual energy consumption down to 0 kWh/m² with help from on-site renewable energy sources and can benefit from materials and methods which are used to meet the passive house demand constraint of 120 kWh/m² which will minimize the need for the often costly on-site renewable energy sources. Energy Plus houses are similar to both ''passivhaus'' and ZEB but emphasize the production of more energy per year than they consume, e.g., annual energy performance of −25 kWh/m² is an Energy Plus house.

Comparison to the Zero heating building

With advances in ultra low U-value glazing, a "passive house" based (nearly)

zero heating building Zero-heating building or nearly zero-heating building (nZHB) is a building having essentially zero heating demand, defined as having heating demand, Q’NH, less than 3 kWh/(m2a). The zero-heating building is intended for use in heating-dominated ar ...

is proposed to supersede nearly-zero energy buildings in EU. The zero heating building reduces on the passive solar design and makes the building more opened to conventional architectural design. The annual specific heat demand for the zero-heating house should not exceed 3 kWh/m²a. Zero heating building is generally considered to be simpler to design and to operate as there is no need for modulated sun shading.

Tropical climate needs

In a tropical climate, ''passivhaus'' standard have proven to be helpful for ideal internal conditions by using

energy recovery ventilation Energy recovery ventilation (ERV) is the energy recovery process in residential and commercial HVAC systems that exchanges the energy contained in normally exhausted air of a building or conditioned space, using it to treat (precondition) the in ...

instead of

to reduce the humidity load of ventilation on the mechanical dehumidification system. Although dehumidifiers might be used, heat pump hot water heaters also will act to cool and condense interior humidity (where it can be dumped into drains) and dump the heat into the

hot water tank A hot water storage tank (also called a hot water tank, thermal storage tank, hot water thermal storage unit, heat storage tank and hot water cylinder) is a water tank used for storing hot water for space heating or domestic use. Water is a con ...

. Passive cooling,

solar air conditioning Solar air conditioning, or "solar-powered air conditioning", refers to any air conditioning (cooling) system that uses solar power. This can be done through passive solar design, solar thermal energy conversion, and photovoltaic conversion (sunl ...

, and other solutions in

have been studied to adapt the "passive house" concept for use in more regions of the world. A certified "passive house" was built in the hot and humid climate of

Lafayette Lafayette or La Fayette may refer to: People * Lafayette (name), a list of people with the surname Lafayette or La Fayette or the given name Lafayette * House of La Fayette, a French noble family ** Gilbert du Motier, Marquis de Lafayette (1757� ...

Louisiana Louisiana , group=pronunciation (French: ''La Louisiane'') is a state in the Deep South and South Central regions of the United States. It is the 20th-smallest by area and the 25th most populous of the 50 U.S. states. Louisiana is borde ...

, USA. It uses

and an efficient one ton air-conditioner to provide cooling and dehumidification. Solar access have been a very important factor in any design of a passive house as it allows the structure to use the solar energy to heat and light the space naturally, and to replace electrical water heaters with solar energy-based water heaters.