The sustainable architecture , also named as green architecture , eco-architecture and environmentally conscious architecture is a way of conceiving the design architecture so sustainable , seeking to optimize natural resources and systems of the building, so as to minimize the environmental impact of buildings about the environment and its inhabitants.

The principles of sustainable architecture include:
  • The consideration of the climatic conditions , the hydrography and the ecosystems of the environment in which the buildings are constructed, to obtain the maximum performance with the least impact.
  • The efficiency and moderation in the use of construction materials , with a preference for those with a low energy content compared to those with a high energy content.
  • The reduction of energy consumption for heating , cooling , lighting and other equipment, covering the rest of the demand with renewable energy sources .
  • The minimization of the overall energy balance of the building, covering the phases of design, construction, use and end of its useful life.
  • Compliance with the requirements of hygrothermal comfort , health , lighting and habitability of buildings.

Origin of the term

The term "sustainable architecture" comes from a derivation of the term " sustainable development " (of English : sustainable development ) that the Norwegian prime minister Gro Brundtland incorporated in the report Our Common Future ( Our Common Future ) presented on 42 at session of the United Nations in 1987. "Development is sustainable when it meets the needs of the present generation without compromising the ability of future generations to meet their own needs," said Gro Bruntland. The report emphasized that the impoverishment of the world's population was one of the main causes of global environmental deterioration. In 1992 the heads of state meeting at the Earth Summit in Rio de Janeiro undertook to jointly seek "... the development paths that respond to the needs of the present without compromising the abilities of future generations to meet theirs" .

Thus the concept of sustainable development is based on three principles:
  • The analysis of the life cycle of the materials;
  • The development of the use of raw materials and renewable energies ;
  • The reduction of the quantities of materials and energy used in the extraction of natural resources , their exploitation and the destruction or recycling of waste .
During this meeting in Rio de Janeiro a parallel meeting was held, convened by academics, researchers and global NGOs to discuss what was the state of knowledge in each field with respect to each line of knowledge. There were hundreds of jobs worldwide among which were the architects with environmental awareness mainly from previous trends such as solar architecture , the bioclimatic architecture or alternative architecture .

Despite the initial caution of the academic world when it comes to agreeing on new concepts and their inclusion in the Dictionary of the Royal Spanish Academy , it was possible to translate "sustainable" as " sustainable ", meaning already fully accepted by this institution. On the contrary, the term " sustainable " has no relation whatsoever to this concept, and is considered an Anglicism when it is used as a substitute for sustainability, despite being widely spread in Latin America .

In 1998 the School of Architecture and Urban Planning of the University of Michigan published the document An Introduction to Sustainable Architecture, which synthesizes the principles of sustainable architecture.

In 2004 the Dictionary of architecture in Argentina was published , where the voice "bioclimatic / bio-environmental / solar passive / sustainable / environmentally conscious (Architecture)" appears to unify a line of thought of architecture. And it is defined: "... applied to design and architecture, these adjectives are integrated into constructions that designate the strategies and buildings that are conceived, constructed and work according to the environmental conditions and possibilities of the place (climate , ecological values), its inhabitants and ways of life.This is achieved through two subsystems: the conservation and rational use of energy and the passive solar systems, both incorporated into the architectural body. By extension they apply to town planning ... ".

Given that the controversy continued, it was not strange that only in October 2005 , the first International Seminar on Sustainable, Sustainable and Bioclimatic Architecture was held in the city of Montería ( Colombia ) , in order to bring Ibero-American specialists together to resolve the approach of each sub-stream and find agreements.

In March 2006 the collectible Sustainable Architecture was published in the newspaper with the largest circulation in Argentina , to clarify to the community of architects the use of the term, to explain its foundations, to analyze ten significant works worldwide, together with a manual of application for the climates of the country.

In 2009 the Laboratory of Architecture and Sustainable Habitat - LAyHS was created in the Faculty of Architecture and Urbanism of the National University of La Plata ( La Plata , Argentina ) in order to carry out R & D in this current of architecture. In 2011 its members promoted the creation of a Master's degree and Specialization in Architecture and Sustainable Habitat, which was approved in 2012 and accredited by the National Commission for University Evaluation and Accreditation in 2014 and started its operation.

In 2011, the creation of a career in architecture focused on Urban Development and Sustainable Architectural Design was approved at the National University of Cuyo (Mendoza, Argentina), in order to train architects with a focus on bioclimatic design and sustainable.

Also in 2011, Universidad del Bío-Bío created the magazine Habitat Sustentable , in Open Journal Systems format with the support of the Chilean Energy Efficiency Agency (AChee).

In 2012, the Higher Institute of Architecture and Design - ISAD ( Chihuahua , Mexico), created the Master's Degree in Sustainable Architectural Design. In 2014, the Environmental University of Mexico created the Master's Degree in Architecture, Design and Sustainable Construction. In the same year, the Universidad Motolinia del Pedregal de México created the Master's Degree in Architecture and Sustainable Design. In the Faculty of Architecture of the UNAM (Mexico), the Sustainability Laboratory - LASUS is created. In Spain at the University of Valencia The Advanced Professional Master's Program in Sustainable Architecture and Bioclimatic is created, showing the use of the term sustainable in the Iberian Peninsula.

Also in 2013, the CONICET of Argentina modified the name of the historic Habitat Commission, which brought together researchers and doctoral scholars architects, engineers, sociologists, anthropologists, environmental psychologists, physicists in renewable energies, by the name of the Commission of Habitat, Environmental Sciences and Sustainability . In this way, it brings together other researchers from biology, agronomy, the exact and natural sciences who sought to group themselves in the growing field of knowledge that deals with the relationship between man and nature.

This shows the institutional consolidation that this current of thought in architecture is achieving, together with the architects' commitment to become aware of the environmental impact caused by their professional practice in relation to climate change , its mitigation and adaptation .

Energy and architecture

The energy efficiency is one of the main goals of sustainable architecture, although not the only one. Architects use various techniques to reduce the energy needs of buildings by saving energy and to increase their ability to capture the sun's energy or generate their own energy .

These strategies of sustainable design include active and passive solar heating, solar heating of active or passive water , solar electricity generation , groundwater or geothermal heating , and more recently the incorporation of wind generators into buildings .

The considerations specified refer both to aspects concerning the materials used, technologies used to obtain greater energy efficiency of the house and construction techniques.

The environmental impact of building design, construction and operation are enormous. As an example, buildings in the United States are responsible for 39% of CO 2 emissions , 40% of primary energy consumption, 13% of drinking water consumption and 15% of GDP per year.

Efficient heating

HVAC systems (whether heating , cooling or both) are a primary focus for sustainable architecture because they typically consume the most energy in buildings. In a passive solar building the design allows these to take advantage of the sun's energy efficiently without the use of certain special mechanisms, such as: photovoltaic cells , solar panels , solar collectors (water heating, heating, cooling, swimming pools), valuing the design of the windows . These special mechanisms are framed within the so-calledactive solar systems . Buildings designed by passive solar design incorporate the thermal inertia by using construction materials that allow the accumulation of heat in the thermal mass such as concrete , the masonry of common brick , the stone , the adobe , the wall , the floor cement , water, among others (case wall Trombe - Michel ). It is also necessary to use thermal insulationto conserve the accumulated heat during a sunny day. In addition, to minimize heat loss, buildings are made to be compact and achieved by a surface of walls, ceilings and windows that are low compared to the volume they contain. This means that wide-open multi-wing or spine-shaped designs should be avoided by preferring more compact and centralized structures. The traditional high-density buildings in very cold climates are a good historical model for an energy-efficient building .

The windows are used to maximize the entry of light and energy from the sun to the indoor environment while seeking to minimize the loss of heat through the glass (a very bad thermal insulator). This usually involves installing more glazed surface in the direction with greater solar exposure, to capture the sun in winter and to restrict as much as possible the glazed surfaces to the opposite side. This strategy is suitable in temperate to very cold climates. In warm climates to tropical, other strategies are used. The use of hermetic double glazing ( DVH)) reduces heat losses by half, although its cost is significantly higher. It is advisable to plant in front of the windows oriented to a greater solar exposure deciduous trees, to block the excessive sun in summer and at the same time allow the passage of sunlight in winter, when their leaves disappear. Perennial plants are often planted south of the building to act as a barrier against the cold winds of the south.

Efficient cooling

When, due to particular conditions, the use of passive cooling is impossible , such as, for example, buildings in very dense urban areas in climates with hot summers or with uses that involve a large generation of heat inside ( artificial lighting , electromechanical equipment, people and others) ) it will be necessary to use air conditioning systems . Since these systems usually require a large energy expenditure to extract heat from the interior of the building, then it is necessary to use strong and active strategies of sustainable design. Among other:
  • Adequate sun protection on all glazed surfaces.
  • Avoid the use of glazing on ceilings.
  • Good thermal insulation in walls, ceilings and glazing.
  • Concentrate the spaces of great heat emission (example: computers, kitchens, etc) and give them good ventilation.
  • Sectorize spaces according to uses.
  • Use air conditioning systems with energy certification in order to know how efficient they are.
  • Ventilate buildings at night.
This will help reduce global warming and the ozone hole in the atmosphere.

Passive cooling

In very hot climates where cooling is necessary passive solar design also provides effective solutions. Building materials with high thermal mass have the ability to preserve cool temperatures at night throughout the day. For this, it is necessary to have thicknesses in walls or ceilings that vary between 15 and 60 cm and thus use the envelope of the building as a heat storage system . It is necessary to foresee adequate night ventilation that will sweep the greater internal surface avoiding the accumulation of diurnal heat. Ventilation inside the premises can be significantly improved with the installation of a solar chimney

During the day ventilation should be minimal. Thus, when the walls and ceilings are fresher, they will take on body heat, giving a sensation of freshness.

In very hot climates buildings are designed to capture and channel existing winds, particularly those that come from nearby sources of moisture such as lakes or forests. Many of these valuable strategies are employed in a certain way by the traditional architecture of warm regions.

In very hot and dry climates with a high content of atmospheric dust , wind sensors can be used to drive the air to low points, and can also filter and moisten the air to remove heat by evaporative cooling or lead it to internal patios with fountains or ponds. way to refresh the interior environment.

Production of alternative energies in buildings

The alternative energies in the architecture imply the use of devices active solar , such as photovoltaic panels or wind generators that help provide sustainable electricity for any use. If the ceilings are pending, try to locate them towards solar noon with a slope that optimizes the capture of solar energy so that the photovoltaic panels generate maximum efficiency. To know the optimum slope of the photovoltaic panel in winter (when the day is shorter and the solar radiation weaker) we must subtract the value of the latitudeof the place the angle of the height of the sun. The height of the star will be obtained from a solar chart.

Buildings have been built that even move through the day to follow the sun. Wind generators are being used more and more in areas where the wind speed is sufficient with sizes smaller than 8 m in diameter. The solar heating systems activated by water cover all or part of the heating needs throughout the year in a sustainable manner.

Buildings that use a combination of these methods achieve the highest goal, which is a zero energy demand and in the 80sthey were called self-sufficient. A new trend is to generate energy and sell it to the network for which it is necessary to have specific legislation, policies to promote renewable energies and state subsidy programs. In this way, the excessive costs represented by energy accumulation systems in buildings are avoided. One of the most striking examples is the Academy of Mont-Cenis in Germany of architects Jourda & Perroudin the opened in 1999.

Other forms of energy generation based on renewable sources are solar thermal energy (for heating, sanitary hot water and air conditioning), biomass or even geothermal energy . The ideal to guarantee the energy supply throughout the year, under changing climatic and environmental conditions, is to combine the different sources.

Sustainable skyscrapers: green architecture

It is possible a skyscraper architecture that respects the environment and above all that is sustainable, as is the case of vertical architecture. It would be produced from the building's own resources, which would be areas such as all types of departments and establishments, but with self-sufficiency with renewable and non-polluting energy. In short, skyscrapers can be adapted to green and sustainable architecture.

Green architecture does not only refer to the implantation of plants and plants in urban constructions and buildings, as has traditionally been considered, but also to the use of techniques based on sustainability and renewable energies. The term green refers only to plants, but the color of a whole movement in favor of taking care of the environment and therefore our planet.

If cities continue to experience vertical growth in the coming years, how will architects design the skyscrapers of the future? This is the question that is asked every year by the eVolo architecture magazine, which since 2006 has been organizing the 'eVolo Skycraper Competition', a contest in which renowned architects choose the best designs of the possible skyscrapers of tomorrow for their creativity, ingenuity and his way of understanding vertical communities.

First prize: 'Essence Skycraper'

The organizers have received more than 480 original projects from all corners of the planet, and this year the first prize went to four Polish architects and architects from the BOMP studio for their project 'Essence Skycraper', a gigantic mega structure that houses not only boring buildings of offices, but up to eleven different landscapes inside.

Oceans, jungles, caves and waterfalls can be architectural elements in this secret garden of immense proportions, where we will not even have to leave the building to go to nature and get away from the frenetic pace of the city.

Energy recycling

The most economical alternative to achieve an energy efficient building is including the theme from the project phase. But it is possible to take an existing building and using a technique called energy recycling known by its Anglo-Saxon roots as retrofit give the building a new sustainable life cycle .

Among the first tasks is to perform an energy audit to know what are the inputs and outputs of energy to the building as a system, always seeking to maintain hygrothermal comfort , health and safety.

Implementation and location

The location of the building is a central aspect of sustainable architecture and often is not taken into account. Although many environmentalists suggest the location of the ideal home or office in the middle of nature or the forest this is not always advisable; since it is harmful to the natural environment. First, such structures often serve as the last line of attraction for the suburb of cities and can generate a tension that favors their growth. Secondly, being isolated increases the consumption of energy required for transport and generally leads to unnecessary greenhouse gas emissions. An urban or suburban location near communication routes should be sought, seeking to improve and strengthen the area. This is the current trend of the new urbanist movement. A careful mixed zoning between industrial (clean), commercial, and residential areas implies better accessibility to be able to travel on foot, by bicycle, or using public transport.

Materials for sustainable buildings

The products can communicate environmental throughout its life cycle on the basis of a number of categories defined in International Standard impact impacts ISO 14025 through one environmental Statement product (DAP). DAPs are a type of Ecolabels defined in international standards ISO ( International Organization for Standardization ). The categories of impact included, based on a life cycle analysis , make reference, among other parameters, to depletion of resources or the potential for global warming. At European level there is a framework standard for DAP, EN 15804 , issued by the European Committee for Standardization (CEN) . Both standards are published in Spanish by AENOR.

The DAPs are verified through a Program Administrator. In Europe ECO Platform brings together the main DAP Verification Administrators. In Spain, the Program Administrators are the Building Surveyors, Technical Architects and Building Engineers of Barcelona , which issues DAP under the name DAPcons and AENOR , which issues DAP under the name GlobalEPD.

The assessment at the building level based on environmental declarations can be made based on the European standard EN 15978 , also issued by CEN and which uses the same modular structure to define the different stages of the building's life than that used in the European standard of DAP (EN 15804).

The materials suitable for use in sustainable buildings must have characteristics such as low energy content , low emission of greenhouse gases such as CO2 - NOx - SOx - particulate material, be recycled, contain the highest percentage of reuse materials, among others. The construction industry consumes 50% of all the world's resources and becomes the least sustainable activity on the planet. In the case of woods, avoid those from native forests and use wood from crops such as pine , eucalyptus and other species.

Among the materials used in the construction that own more energy own are primary aluminum (215 MJ / kg), commercial aluminum with 30% recycled (160 MJ / kg), neoprene (120 MJ / kg), paints and synthetic varnishes (100 MJ / kg), polystyrene is expanded or extruded (100 MJ / kg) and primary copper (90 MJ / kg), together with polyurethanes , polypropylenes and PVC polyvinyl chloride.

Waste management

Sustainable architecture focuses on the use and treatment of waste at the site, incorporating such things as gray water treatment systems through filters and biological stabilization with reeds and other aquatic plant varieties . These methods, when combined with the production of compost from organic waste , the separation of waste , can help minimize the production of waste in a house .

Recycling of structures and materials

Sustainable architecture can use recycled or second-hand materials. The reduction of the use of new materials generates a reduction in the use of the energy of each material in its manufacturing process. The architects try to adapt old structures and constructions to respond to new needs and in this way avoid as much as possible constructions that start from scratch.

Recycled materials

Among the possible materials for recycling are:
  • the masonry in the form of crushed rubble to make subfloors or Roman wells
  • wood of different roof, panel and floor systems.
  • pavement concrete, which is crushed again and used in structures with less load compromise.
  • doors, windows and other openings.
  • thermoacoustic insulators.
  • majolicas and other ceramic coverings.
  • metal pipes.
  • sheet metal covers for construction fences.
  • structural iron for minor works.
  • bars.

In non-developed countries it is usual to have a great recovery of demolitions and sites where these products are concentrated for later reuse. In Argentina they are called Chacaritas in allusion to the largest cemetery in Buenos Aires.

Architecture and social sustainability

Architecture generates a great social impact on the population and good examples are needed in each local community to show society the paths to follow. In each culture in time new types of buildings emerged, but only some of these buildings became models to be repeated by society.

The first concept model was designed by architect George Fred Keck in 1933 for the Universal Exhibition of Chicago and was called the House tomorrow (House of Tomorrow). By 1940, Keck built for the real estate entrepreneur Howard Sloan in Glenview, Illinois a passive solar house that was called "Solar House or Solar House " by the Chicago Tribune , and is the first known use of the term.

In the experimental field, the first systematic developments were grouped in what was called " List of pioneering solar buildings " that shows a continuous production by the academic world since 1939 when the MIT Solar House # 1 was built in Michigan by HC Hottel of the Masachusset Institute of Technologies - MIT .

While lightweight construction houses (100 to 150 kg / m²) are common in the United States , in South America they are mostly heavy construction (> 150 kg / m²). The materials and construction methods are probably different because of the culture that each building type brought. Since changes in customs are not simple, enormous efforts are required to generate valid alternatives that are adopted by society.

Here enter concepts such as what is the initial cost of a building , what is the cost over its useful life (estimated in 30 to 50 years), the vulnerability of the buildings and the risk analysis, can a family or a society pay such costs? Can the environmental cost be addressed ? They are all questions that each local society must answer and the leadership must give adequate and sustainable answers.