GREEN BUILDING – DEFINITION
GREEN BUILDING – ECOLOGICAL CONSTRUCTION
The notion of
varies depending on the specialist. For eco-builders, it means a clean building, using natural materials. They consider that a building must above all adapt to humans, the well-being of its occupants being capital. These partisans of green building condemn the use of toxic substances in the industrial manufacture of construction materials. Experts in energy savings aim to limit the negative impact of human habitat on the environment through ultra-modern technologies and to reduce the amount of energy consumed by buildings, houses and apartments. They recommend enhanced thermal insulation and leading-edge construction techniques. Eco-builders consider a building over its whole lifetime. Not only do they integrate energy savings, they also take into consideration the origin of the materials used and their management (elimination, recuperation) at the end of their life.
Eco-construction, also referred to as sustainable construction or green building, proposes various possibilities of reducing the environmental impact of buildings. Green building is not a specific construction method, but it brings together a set of techniques, materials and technologies which when suitably integrated in a construction project, contribute to enhancing its environmental performance. In an ideal world, eco-construction optimises energy efficiency, limits water consumption, makes maximum use of recycled, recyclable and non-toxic materials. It also generates as little waste as possible during the construction process and subsequent occupation.
In a green building, the structural creation processes respect the
and make efficient use of resources. This
is growing and complements the conventional concerns of designing buildings that are economical in energy, sustainable and comfortable. A green building is a clean, sustainable building, designed with natural materials, uses little energy and renewable ones at that, is easy to maintain and available at a reasonable cost.
A green building is designed to reduce the overall impact of the built-up environment on human health and the natural environment, through:
• The efficient use of energy, water and other resources
• Protecting occupant health and improving employee productivity
• Reducing waste, pollution and harm to the environment.
Effectively, a green building can incorporate sustainable materials (reused, recycled, recyclable, or from renewable resources) in its construction, create a healthy interior environment with a minimum of pollutants and functional landscape planning that requires less water (using indigenous greenery that thrives without additional watering).
Clean building is an eco-construction or green building approach that aims to build in respect of our environment and that of future generations, while offering maximum comfort to occupants. It is also an approach that involves:
• The identification of the environmental impacts of projects throughout their lifecycle;
• The use of architectural and urban-planning techniques that prioritise natural light, integrate bio-climate principles, guarantee good thermal insulation of the whole building envelope and respect applicable legislation;
• The use of “environmental” or “natural” materials that consume little energy in their manufacture, transport and deployment;
• The promotion of the use of renewable energies and/or low-pollution fuels;
• The use of “intelligent” equipment: “Low energy” lighting and household appliances, efficient correctly-sized heating systems.
What is more, there is no clean habitat without a clean building site. To choose the right location, we must always start by considering the influences of the soil (contaminated sites, natural radioactivity, etc.) or the environment (noisome roads, industrial plants emitting toxic emissions, high voltage power lines) that may be troublesome. Installation in the route of a wind corridor, even within a large town, means the site will benefit from a pleasant atmosphere, rich in oxygen.
Green building uses resources efficiently. Its success is to leave fewer traces on the environment through the use of renewable energies and by ensuring high energy yield. This is a balanced solution between construction and a sustainable environment.
THE GREEN BUILDING
A natural green building construction must satisfy two additional imperatives: the adaptation of the architecture to the landscape and its measurable data, alongside the use of natural materials, which if possible are renewable. The choice of the site must be made according to natural data. In effect, topological data have a great influence on the micro-climate and therefore on the properties of a building site. So in a basin where cold air stagnates, temperatures can be 6°C below those on a flat terrain just a few hundred metres away.
Architectural forms must be inspired by nature, with colours that do not seem artificial. Natural building techniques use the materials that nature provides. When these materials replace polluting synthetic products which consume a large quantity of energy in their manufacture, their use is highly recommended. The term “natural materials” essentially covers local (renewable) raw materials that can be used according to traditional craft methods or modern techniques.
The expression “passive building” refers to a construction standard that can be achieved using various types of construction materials. It can also mean a green building construction that guarantees an interior climate as comfortable in summer as it is in winter without a conventional heating system. Taken from the German word “Passivhaus,” this expression concerns both collective and individual habitats. The purpose of the passivhaus is to reduce energy consumption in residential buildings by capturing a passive solar energy contribution, reinforcing building insulation, using renewable energies and recuperating heat.
A passive building consumes no more than 15 kWh/m2/year for its heating and no more than 30 kWh/m2/year for heating, hot water and ventilation. Total consumption (including household appliances) must not exceed 120 kWh/m2/year in primary energy (that which is taken from nature before transformation). The passive building mark includes many specific and technical elements concerning windows, insulation and facade seals, air renewal, etc. Rigorous testing is carried out to obtain the passive building mark.
Individual passive houses are often compact. This is one condition for achieving low energy consumption. To build a passive building, the following requirements must be satisfied:
• Excellent insulation all over the building, exterior insulation from 25 to 35 cm;
• High quality triple-glazed windows;
• Building orientation to capture passive solar energy and large south-facing picture windows;
• A dual-flow mechanical ventilation system with a heat recuperation rate of at least 75%.
• Solar thermal units for hot water requirements.
There remains a great deal of effort to make in promoting eco-construction and renovation with our populations. Today the majority of people recognise the expression Green Building and most consider it with a positive connotation. Among those who perceive eco-construction under a positive light, many are ignorant of the specific nature of such practices. The often ignore what distinguishes them from conventional construction methods, how they are integrated into residential construction and what the selection of ecological options implies for companies and acquirers.
Therefore within the population there is a lack of information, combined with the circulation of several misconceptions. In fact, most people associated a particular architectural style with eco-construction, something modern and contemporary, with the addition of complex systems such as solar panels and water heaters, geothermal systems or green roofs. Promotional communication should accentuate the fact that it is possible to build a high-performance eco-home which neverthless has traditional aesthetics. What is more, subtle or even invisible measures, such as low-emission windows, high-quality ventilation ducts and suitable insulation make a significant contribution to the energy efficiency of a home without changing its physical aspect or rendering the construction process overly complicated.
For optimum operation, ecological methods and technologies must be integrated into a coherent design. The expectations of today’s owners and occupants in terms of maintenance, operation and comfort are very high, which results in corresponding technological and energy costs. An important vector for promoting ecological construction is construction regulations.
GREEN BUILDING – COMPONENTS
ENERGY EFFICIENCY AND RENEWABLE ENERGY
Energy efficiency is a major concern and an essential component of green building. It has even become a major factor in its success. A green building must always be fitted with solutions that offer enhanced electrical energy management, reduce consumption and contribute to supplying quality energy.
This efficiency can be materialised in a home through the use of occupancy detectors and full home automation systems. All these solutions help to manage and programme lighting, heating and other uses to optimise their use at a lower cost. In commercial buildings, solutions are multiplied to reduce energy use and contribute to reducing greenhouse gases, both in lighting management, office equipment management, security lighting, infrastructure measurement and surveillance. In such buildings, capacitor banks increase the efficiency of the installation and network analysers make it possible to measure the consumption and quality of the energy.
Renewable energy sources present the advantage of being available in unlimited quantities. Their use is a way of satisfying our energy needs while conserving the environment. The main forms of renewable energy are solar power, wind power, biomass power, geothermal power, hydraulic power, etc.
The energy produced by photovoltaic panels is an undeniable component of renewable energy production, which must satisfy the dual issue of integration into buildings and optimised production. Heavy investment in various clean energy technology projects around the world have been undertaken to improve the efficiency of renewable energies, to reinforce the economy, protect the environment and reduce our dependence on oil products.
Energy efficiency and green building
For the past 10 years, observers have complained about peaks of energy consumption due to air conditioning equipment. Among other factors, they point out unsuitable dimensions, non-existent or unsuitable cleaning and maintenance, the use of obsolete and energy-inefficient technologies. To stop energy waste, air conditioning systems are subject to regular inspections. In effect, a decree and law now require that owners have their units regularly inspected, every 5 years at least, by a certified technician.
In France, this concerns decree 2010-349 of 31 March 2010 and the administrative order of 16 April 2010. These legal texts continue the enactment of the European Directive on Building Energy Performance in French law and the implementation of the Grenelle Environment round table recommendations. The aim is to end wasteful use of energy. Air-conditioning systems and reversible heat pumps with a rated cooling power above 12 kW are equipment for home comfort. Their energy use is not in proportion to actual needs, either because they are incorrectly dimensioned, or that they are not correctly maintained or managed. Cooling systems for computer rooms and industrial use are not concerned by these texts. Waste is not welcome in a green building.
Specific electricity corresponds to that required for services that can only be provided through the use of electricity. Items that are not taken into account in specific electricity include hot water, heating and cooking, which can use other types of power. Specific electricity consumption has doubled over the past 20 years and this trend is likely to continue. Choosing energy-efficient appliances is therefore of great importance in a green building.
Efficient appliances will make significant savings on the specific electricity bill. For example, the savings generated by low energy lamps reduces costs by a factor of 4 compared to incandescent lamps. For cooling appliances, the difference in consumption between two different new machines can be anywhere from 1 to 3. Note also that a new appliance can consume up to six times less than an aged appliance.
By energy savings, we mean all economically interesting actions undertaken to reduce energy consumption, by for instance installing suitable equipment in electrical installations. The aim is also to consume energy in an optimal manner (e.g. recuperate heat lost in combustion gases or produce energy from waste). We should be aware that energy savings do not concern just electricity. Adopting some simple daily habits along with a judicious choice of equipment also enables us to control consumption of all other forms of energy (gas, heating fuel, etc.). In a green building, the main priority is to identify energy savings.
Some of the main measures that enable energy savings are:
• Good thermal insulation of all exterior components (walls, windows, roof, etc.)
• Eliminate thermal bridges and other energy leaks
• Good airtight seal on the exterior building envelope
• Reduction of thermal losses through ventilation
• Efficiency of a reduced-inertia boiler
• Optimised electricity management (reduction of installed power ratings, central management, use of lighting control equipment, etc.).
Solar power systems
Solar energy is the source of the water cycle and of wind. The plant kingdom, on which the animal kingdom depends, also uses solar energy by transforming it into chemical energy through photosynthesis.
Apart from nuclear power, geothermal energy and tidal power, solar energy is the origin of all other energies on Earth. Solar energy is also inexhaustible on a human timescale and hugely abundant. It is estimated that the Earth receives from the sun about 10,000 times the total amount of energy consumed by all of humanity. Solar power capture technologies can be split into three categories: Solar photovoltaic, solar thermal and solar thermodynamic. The use of solar power is of tremendous importance in a green building.
Solar heating systems can be installed in all types of buildings. Using solar power to pre-heat outside air before it is allowed to enter a building can considerably reduce heating costs both in residential buildings and commercial constructions. Solar heating systems are especially efficient for large buildings such as hospitals, hangars, school and gyms, as well as multi-storey residential buildings. To make solar electricity available on a large scale, scientists and engineers around the world have been trying to develop a low-cost solar cell for many years. Such cells must be very efficient and easy to manufacture, with a high yield.
The vast majority of solar heating systems require the installation of solar walls. Such equipment can be installed on new or existing buildings. Solar walls require very little maintenance, feature no liquids or detachable parts other than the ventilators connected to the ventilation system. Moreover, solar walls can operate under cloudy conditions and at night time, even if their efficiency is much less. The ROI is two years due to the energy savings they produce.
Geothermal energy is extracted from the ground for use in air conditioning, heating or transformation into electricity. Installing a geothermal heat pump system represents a major investment, but it enables users to make use of an inexhaustible source of energy that will provide 60 to 70% of the power required to heat a building. Geothermal systems can be installed on new houses or renovation projects. This technology can therefore considerably reduce the use of fossil fuels or electricity, which emit much more greenhouse gases and which are generally less financially interesting in the long term. Geothermal technologies are naturally included in green building parameters.
Geothermal systems present some major advantages. Effectively, underground heat is present everywhere on Earth. Geothermal energy comes from an almost continuous source that is not dependent on atmospheric conditions. The ease of extraction of this energy depends on the structure of the geological formations or the composition of the rock beds. This technology is split into two categories: Deep geothermal or near-surface geothermal energy.
Other energy sources
Alongside solar energy and geothermal energy, wind power is the third major source of green building energy. Today wind power is the least expensive clean energy to produce, which explains the strong enthusiasm for this technology. Current research could enable it to keep this comfortable head start for several years to come. Water or hydraulic power is mainly produced by the displacement or accumulation of fresh water or sea water. As it is everywhere, water plays an extremely important role in transporting the Earth’s energy.
Biomass is generated by photosynthesis, where solar energy is stored by plants in the form of carbohydrates, as they use the carbon dioxide in the atmosphere. In a wide sense, the expression “biomass” refers to all living matter (the total mass of living matter). In terms of energy, biomass refers to all organic material that can become a source of energy in the form of biogas, biofuel or directly by combustion: Wood or organic agricultural or urban waste, etc. Biomass energy is used by the biogas, biofuel and wood industries.
The radiant system is a comfortable heating system. Radiant heating transfers heat directly from the floor to your body as well as heating the ambient air. Radiant heating systems produce uniform temperatures in all rooms or heated floor areas, in all seasons. Radiant heating is also a technique to prevent the transmission of dust and pollen, which are prevalent in warm air heating systems.
Sustainable water management
Water savings in a green building
The availability of fresh water has become a matter of increasing concern in a context where developed and developing countries are engaged in a race to obtain resources that are inexorably becoming scarcer. A green building must therefore be designed to use water efficiently. Managing waste water, irrigation water and rain water are also essential for a sustainable approach.
The use of mixer taps reduces water consumption as it is easier to control the temperature. Aerator tap fittings reduce the amount of water used without it being noticed during use. Waste through negligence is to be avoided. Even if repairing a leaking tap can be a chore, tens of millions of cubic metres of water are lost every year, just in France, because of inadequate seals on taps.
Thermostatic mixer taps can also generate savings. As water runs at a predetermined temperature, the water that is usually lost when adjusting a shower temperature is saved. An efficient and sustainable water-saving approach also depends on existing knowledge or projections of water use, tracing and preventing leaks. Replacing unsuitable equipment and using water-efficient devices, communicating and raising user awareness are also potential sources for water savings.
Recuperation and use of rain water
Rain water is an inexhaustible natural resource which has its place in the green building. Rain water is collected as it runs off a roof and is stored in a tank. Whether polluted or not, rain water is naturally slightly acidic (pH from 5 to 6), due to its carbon dioxide content, present in the atmosphere. This acidity means it should not be stored in plastic or metal containers. For domestic use, the ideal solution is a concrete or limestone tank that neutralises the natural acidity of rain water.
Rain water is only rarely recuperated and often only used for watering gardens. Its use should nonetheless be systematic both to unblock waste networks and to save on a resource that is becoming scarcer and is weighing on household budgets. A farmer’s common sense has always encouraged them to put a container under the gutter pipe to recuperate rain water. If optimised, rain water collection can enable homes to be autonomous in water use, without it being visible or visually un-aesthetic.
In certain buildings, rain water is recuperated, treated and reused in applications that do not require potable water. This kind of solution helps reduce fresh water needs in the public network, while avoiding the propagation of pollutants by run-off. Other solutions are available, such as green roofs, which not only store rain water, but also provide a green oasis in an urban environment along with many other benefits.
Reduction of waste and toxic substances
A good green building design helps the occupants to reduce the quantity of waste generated. It also offers solutions such as composting bins, to reduce the volume of matter going to landfills. The green architect also aims to reduce waste in terms of energy, water and materials used for the construction. This considerable reduces the volume of waste sent for disposal during the construction phase. Green building avoids the systematic burial of materials retrieved from buildings at the end of their life by recycling and recuperating them. The extension of the useful lifetime of a structure also enables waste reduction.
The quality of interior air is an important factor in a green building. To do this, it must also seek to reduce volatile organic compounds (VOC) and other air impurities such as microbial contaminants. The ventilation systems must be well-designed to ensure suitable ventilation and air filtration, as well as to isolate certain activities (kitchens, dry-cleaning, etc.) from other applications.
During design and construction, the choice of construction materials and interior finishing products is made to reduce the amount of toxic substances in the building. In effect, many construction materials and cleaning products emit toxic gases such as VOC and formaldehyde. These gases can have a negative impact on occupant health. By avoiding these products, we can increase the quality of the interior environment in a building.
CONSTRUCTION MATERIALS USED ON A GREEN BUILDING
Wood occupies a primordial place in the green building approach. There are many different possibilities in terms of wooden structure. We can opt for walls with solid wood beams, wall with glued and laminated timber, and the wooden frame structure, which are suitable for an urban environment as from the outside they look identical to a conventional construction. The foundations of these constructions are made of concrete.
The benefits reside in the fact that wood is a clean material that generates neither radon nor static electricity. Wood protects itself naturally as it contains polyphenols of vegetal origin, which have a disinfectant effect. It is also an excellent thermal and hygrometric regulator, regulating ambient humidity like other green building construction materials.
One of its many benefits is its lightness. Wood also resists well to traction and compression along the axis of the tree from which it came. It offers high insulation properties, which enables the construction of thinner bearing walls. Wood offers good insulation both in winter and summer by naturally contributing to the thermal inertia necessary to keep warmth inside during the winter and maintain coolness in summer. It can significantly reduce heating consumption in winter.
The insulating load-bearing clay brick
Bricks are becoming more important in the green building approach. The insulating load-bearing clay brick (“monomur” brick) does not need insulating cladding on either the inside or the outside. It is a self-insulating material. The thermal insulation produced is in fact a combination of insulation and thermal inertia achieved by multiple air holes and extending the thermal path crossing the wall. As a resistant and durable heat regulation system and humidity barrier, the insulating clay brick displays admirable performance. Its efficiency is clearly demonstrated today through many tests and studies.
In addition to all these benefits, the insulating clay brick also offers a technology that simplifies its deployment, respects all construction regulations and makes this material a future concept that is increasingly appreciated by builders. It presents a highly reassuring safety rating. In the event of flooding, the characteristics of the insulating clay brick remain intact after drying out, which is not the case with interior insulation. Without additional insulation, the insulating clay brick is totally non-combustible. It emits no toxic gases in the event of fire. Insulating clay brick elements can easily be used to build buildings that must comply with seismic protection regulations.
The clay brick is a natural temperature controller that retains its properties throughout its lifetime. In winter, the brick absorbs heat from the heating system and redistributes it gradually by radiation, reducing energy consumption by about 10% whatever the source. In summer, it naturally regulates the temperature and retains the coolness offered by nocturnal ventilation all day long, due to its excellent thermal inertia, but on condition that heat is not permitted to enter during the daytime by opening the windows.
Cellular concrete, sometimes referred to as aerated concrete, is a lightweight concrete that is very interesting for green building. It is a combination of water, siliceous sand, cement, lime and air. The lime reacts in contact with the aluminium powder present to 0.05%, emitting hydrogen gas to create the air bubbles. After hardening, the material is fairly light with a density of 400 Kg/m3 as it contains thousands of trapped air bubbles (up to 80% of its volume), and offers excellent thermal characteristics. Also, the expansion agent produced by recycling after chemical bonding with the lime, forms non-toxic calcium aluminates.
The materials used in its manufacture make it an eco-material as it respects the environment. It is 100% recyclable and can be used to cover rubble without risk of polluting soils. Cellular concrete offers a high thermal inertia and enables efficient correction of thermal bridges. It also offers exceptional resistance to fire, in excess of 6 hours. Soundproofing taken into account in the HEQ approach is 49 dB.
The sound-damping performance of these blocks satisfies the most stringent requirements of acoustic regulations in effect for exterior walls. Cellular concrete is a natural mineral, non-combustible material. It offers remarkable protection against fire and its frequent use in industry and buildings requiring such protection is highly appreciated. A wall built of cellular concrete is water tight and can breathe. It is a real humidity regulator: It softens dry air by releasing gas and absorbs excessive humidity in a damp atmosphere. It therefore creates a healthy, pleasant atmosphere throughout the home.
A major benefit of cellular concrete and what sets it apart from other materials is how it controls interior temperatures through thermal inertia. The thermal inertia of this material guarantees high attenuation of external temperature variations. It has an excellent capacity to accumulate heat and return it. This can help reduce the amount of time heating is used in half-season and can even offer natural temperature control in summer.
The Euromac2 structure
This construction system comprises two insulating cladding walls made of high density expanded polystyrene, joined by two metal spacers that are reinforced in their lateral parts by flat metal bands. Then concrete is poured inside the cladding up to a height of 3.6 metres in one go. This wall system is totally seismic-protected and has a variable width of 0.25 m to 0.45 m, with excellent acoustic and thermal insulation properties.
Aside its exceptional thermal insulation properties, it offers excellent acoustic insulation and a fire-retardant effect from 90 to 120 minutes, depending on the thickness of the wall. It naturally insulates the outside from the inside, eliminating all thermal bridges and offering full protection to the construction. This type of construction method can be used for high buildings (up to 10 storeys) and underground basements.
With its reinforced insulation concept for all exterior walls and the slow inertia of its walls, Euromac2 (walls, floors, roofs) is particularly effective for BBC (low energy) buildings (Effinergie, Minergie and passive house certificates) and suitable for green building projects.
GREEN BUILDING – ENVIRONMENT AND CLIMATE
The conservation of natural resources is the main objective of the green building approach. A natural resource is a raw material, whose properties are used by humans or other species to satisfy a need. Natural resources can be used in their raw state, with possibly some processes that do not alter them (the case of vegetal and animal resources, but also renewable energies from air, wind, water and the sun). They can also be transformed to be used. The latter mostly involves fossil fuels such as coal, oil, natural gas or uranium.
We can distinguish two types of natural resources: Biological resources and energy resources. Natural biological resources are the water we drink, the soils that we cultivate, the air we breathe, the forests that provide oxygen for the atmosphere, along with all plant and animal species. Natural energy resources are by definition those we use to produce energy. They include air, the sun, water, geothermal sources, plants and fossil fuels.
We can observe that natural resources are running out and that their extraction has harmful effects: Soil erosion, deforestation, destruction of natural habitats, biodiversity and disappearance of fish stocks. The exploitation of these resources generates pollution which to all evidence harms most countries and represents an increasingly dangerous threat to the quality of water, soil and air. Our current production, construction and consumption models, along with global climate change are factors that lead to us to wonder if the planet’s stock of natural resources will remain sufficient to satisfy the needs of a world population that is growing in number and increasingly drawn to live in cities.
We often distinguish renewable resources and non-renewable resources. In terms of renewable resources, we consider those that naturally regenerate, or those that are in unlimited quantities. The two distinctions (biological or energy resources, renewable or non-renewable) can be further sub-divided. Effectively, a resource can be biological and renewable (air), biological and non-renewable (red tuna in the Mediterranean, very soon), energy and renewable (sun) or energy and non-renewable (coal). Today all natural resources are under threat, not just the finite reserves of energy. The most essential is water, which is cruelly lacking in certain regions of the world.
In France, the law of 15 July 1975 on waste elimination and recuperation of materials defines waste as “any residue of a production process, transformation or usage, any substance, material, product or more generally, any furniture that is abandoned or destined to be abandoned by its owner.” In our current society of consumption, goods circulate quickly and are renewed incessantly due to the existence of disposable goods. Waste is therefore produced in greater quantities and in increasingly complex forms.
There are several waste management principles where use varies according to the country or regions. The hierarchy of strategies (the three Rs): Reduce, Reuse and Recycle: classifies waste management policies according to the priorities we wish to assign. Certain experts in waste management have recently added a fourth R: “Rethink,” which implies that the current system has weaknesses and that a perfectly efficient system would require a whole new vision of waste management.
We now need to consider waste as a resource to be exploited and not as waste that we need to get rid of. The methods used to produce new resources from waste are varied and plentiful: For example we can extract raw materials from waste then recycle them or incinerate them to produce electricity. These methods are in full development, notably thanks to contributions from new technologies.
The recycling of waste as raw materials is becoming increasingly popular, in particular in urban areas where space to open new waste management centres is becoming scarcer. Private individuals are therefore required to participate and selective waste collection is increasingly used. Public opinion is clearly evolving towards a position that in the long term, we cannot just dispose of our waste when raw materials are only available in limited quantities. The green building approach naturally integrates optimised waste management.
Respect for the environment
The commercial and residential construction sector can represent up to 40% of primary energy consumption. Overall, it is also responsible for 20 to 25% of waste dumped and 5 to 12% of total water consumption. The United States Green Building Council considers that on average, green building currently reduces energy consumption by 30%, carbon emissions by 35%, water consumption by 30% to 50%, costs relating to waste by 50% to 90%.
A considerable number of research reports confirm the benefits for health and productivity, environmental properties such as natural lighting, the increased use of natural air for ventilation and humidity reduction, the choice of products with low emission rates for carpets, adhesives, paints and other coatings, as well as interior finishing products. In the USA, the annual cost of sickness related to buildings is estimated at 58 billion dollars. According to researchers, the “ecologisation” of construction could achieve annual savings of 200 billion dollars in the USA, simply by improving worker productivity through the improvements of ambient air in office buildings.
Buildings also influence our quality of life, the deployment of infrastructures and transport networks. Bad land management practices often lead to inefficient use of land, which generates higher energy consumption and increased travel time. This can also result in a loss of productivity, the discharge of polluted run-off water into surface water storage and waste water treatment networks, the loss of farm land, the fragmentation of habitats and financial pressure for local authorities.
Reports produced by the world’s leading scientists stress the need to take action on a planetary scale to manage climate change. According to the forecasts of the Intergovernmental Panel on Climate Change (IPCC), if we do not immediately take sufficient measures to limit greenhouse gases, global warming could have irreversible and possibly catastrophic consequences. Every year, the energy used by buildings ejects thousands of megatonnes of CO2 emissions into the atmosphere.
Reports indicate that energy-efficient buildings are one of the fastest and most economical ways of considerably reducing greenhouse gas emissions, and often a source of net economic benefits. An increasing number of organisations, institutions and government entities are demanding a radical improvement in energy yield in the construction sector. In short, the green building approach represents one of the most likely short term methods of considerably reducing emissions responsible for climate change.
According to the IPCC report (ref 2b, 2007, institutional efforts in favour of eco-construction), the building sectors offer the best opportunity to achieve considerable reductions in CO2 emissions. In its fourth evaluation report, the Intergovernmental panel of experts confirms we should be able to eliminate approximately 30% the world’s emissions of greenhouse gases in the construction sector by 2030. With such reductions in energy consumption, renewable sources could satisfy additional energy needs, which would make it possible us to produce buildings with zero net energy consumption and which are carbon neutral. This limitation of CO2 emissions would also improve the quality of interior and exterior air, increase social well-being and secure our energy resources.
The environmental quality of a green building is its ability to satisfy three complementary requirements:
• Control the impacts of the building on the exterior environment
• Create a comfortable and healthy environment for its users
• Preserve natural resources by optimising their use.
This rule applies to construction but also more widely to urban programmes and land management (business parks, zoning, infrastructures, etc.).
It is a concern that stems from discussions at the Rio summit in 1992, where 164 nations met to talk about sustainable development. The construction of a building can in effect have a major negative impact on the quality of our environment. The building sector consumes: 50% of natural resources, 40% energy and 16% of water.
GREEN BUILDING – CERTIFICATIONS
HIGH ENVIRONMENTAL QUALITY (HEQ)
The HEQ approach
The HEQ approach is proposed to project owners and project managers to make the most appropriate decisions in terms of sustainable development at all phases of construction and the lifetime of a building: Design, construction, use, maintenance, adaptation and deconstruction. Analysis of the solutions that will enable us to achieve the best compromise possible between these occasionally contradictory choices must be done for each operation. Such an approach is not the same from one project to another. Hence it is indeed an approach that aims to favour fully-considered choices made by all stakeholders in construction and future users, in a global cross-functional approach.
A priori this approach is valid for all building sectors, whether new constructions or renovations. But not all buildings are implicated in the same way. Public buildings are the first concerned, as local authorities wish to show the way ahead in this matter. It is an excellent lever to promote a global cost approach, which is still underused, even though it makes better financial sense over the long term for local authorities, which are both project owners and managers of such buildings.
The role of HEQ in the construction of a green building
The HEQ approach gives project owners a work method that guides them in making the most pertinent choices in terms of a green building approach, according to the criteria that they weigh up themselves according to their priorities and the characteristics of their operation. This approach avoids a vast amount of financial waste as it encourages all stakeholders to work together upstream of an operation to analyse all the data together. Included in this waste we can identify: Design errors identified too late on site and which mean deployments must be reviewed, site delays due to opposition from local residents as a result of insufficient consultation, incorrectly estimated maintenance costs, that harshly penalise the life of the building, irrelevant energy consumption, etc.
To the management and construction of a green building, HEQ provides:
• A harmonious relationship between the building and its immediate environment, by organising the building site to create a pleasant environment, by using the opportunities offered by the neighbourhood and the site, by reducing the risks of nuisance between the building, the environment and the site.
• The selection of appropriate construction processes and products
• Low-nuisance sites
• Efficient energy, water and activity waste management
• Advance cleaning and maintenance alongside the integration of maintenance requirements, by deploying efficient technical management and maintenance processes, and by managing the environmental effects of maintenance processes.
With HEQ, buildings offer the following in terms of comfort and health:
• Hygrothermal comfort: Stability of hygrothermal comfort conditions and homogeneity of hygrothermal atmospheres, hygrothermal zoning, according to use;
• Acoustic comfort: Acoustic correction, acoustic insulation, attenuation of impact noise and equipment noise, acoustic zoning, according to use;
• Visual comfort: Satisfactory visual relationship with outside, optimal natural lighting in terms of comfort and energy costs, appropriate artificial lighting as a complement to natural lighting;
• Olfactory comfort: Reduction of unpleasant odour sources, ventilation to evacuate unpleasant odours;
• Sanitary conditions: Creation of satisfactory properties of interior atmospheres, creation of optimal hygiene conditions, ease of cleaning and evacuation of activity waste, creation of facilities for reduced-mobility users;
• Air quality: Management of pollution risks due to construction products, management of pollution risks by equipment, management of pollution risks due to cleaning or improvement, management of risks of polluted new air, ventilation to ensure satisfactory air quality;
• Water quality: Protection of the collective potable water distribution system and maintenance of potable water quality in buildings, possible improvement of potable water quality, possible treatment of non-potable waste water, management of risks concerning non-potable water networks.
Energy choices in HEQ
The first approach to adopt in terms of green building is to deploy all efforts to control energy requirements: This will enable a bio-climate architecture with orientation of the building, recuperation of solar contributions in winter and protection against over-heating in summer. Concerning the choice of renewable energy sources, no one should be singled out as having priority over another, as there exists no energy solution with zero drawbacks for the environment.
Each case must be analysed and comparative studies in terms of overall cost must be systematic to foster reasoned choices. What is more, we use renewable energies in association with conventional sources (wind power, solar thermal, wood, recuperation of calories from air and water, etc.) each time it is possible.
Lastly, we seek to optimise energy use through the use of systems able to adjust energy use to the strict necessities: Programming, power cuts, etc. Commercial and residential buildings generate about 25% of the world’s CO2 emissions. A constant effort to rationalise energy use in buildings can therefore significantly reduce the drift of the greenhouse effect. A HEQ building can therefore make an appreciable contribution to reducing the greenhouse effect.
LEED certification (Leadership in Energy and Environmental Design) is an international certification system for green buildings. It was established in March 2000 by the US Green Building Council, an American association dedicated to promoting financially-sound buildings that are pleasant to live/work in and offering good environmental performance. It also provides tools to assist building owners and operators in areas with human and environmental impacts. Its sustainable development-based approach relies on excellent performance in six major areas of human health and environment:
• Environmental organisation of sites
• Efficient water management
• Energy and atmosphere
• Materials and resources
• Quality of interior environments
• Innovation and design process.
LEED certification satisfies these fundamental needs while offering recognition for the efforts made to achieve them. It enables the reduction of the building’s impact on the environment while minimising costs associated to its life cycle. LEED certification is granted to buildings that have demonstrated viability by respecting the highest performance standards in terms of environmental responsibility and energy efficiency.
Credit to obtain LEED certification
A certain number of pre-requisites are imposed before the LEED green building assessment and rating is carried out:
• Prevention of pollution caused by construction activities (erosion control and sediment management);
• Deployment of basic building energy systems;
• Minimal energy performance;
• Reduction of CFCs in HVAC equipment and fundamental management of refrigerants and elimination of halon gases (halogen bromide chemical compounds);
• Collection and storage of recyclable materials;
• Minimal performance in terms of interior air quality;
• Control of ambient tobacco smoke.
The purpose of these pre-requisites is to control and reduce surface erosion and to reduce the negative impact on surrounding water systems and air quality. Attenuation measures are used to protect the surface soil during construction against rain water run-off and the displacement of sand by strong winds. It also imposes measures to prevent the deposit of sand and other materials in rain water evacuation networks. To satisfy these requirements, certain design measures proposing the anti-erosion cladding, temporary or permanent burial of tanks to trap the materials deposited.
LEED credits per domain
Certification is awarded according to the total number of points obtained subsequent to the verifications and examinations. Each domain has a series of credits covering the most important environmental problems. Each credit can give one or more points according to the progress made in terms of the requirements. The criteria are defined in detailed directives for different types of new or existing buildings, schools, healthcare, commercial buildings and the interiors of green building commercial premises. On the basis of an overall score for the building, a certificate is awarded for the category. For levels of recognition can be awarded depending on the result: Certified, Silver, Gold or Platinum.
The environmental categories are sub-divided into credits according to the desired performance objectives. So points are awarded according to the achievement of requirements.
Environmental organisation of sites:
• Choice of site
• Alternative transport modes
• Fluidity on site
• Minimal disruption caused by site
• Rain water management
• Site layout to reduce the effects of a thermal island
• Reduction of light pollution
Efficient water management
• Innovative waste water treatment technologies
• Reduction in water consumption
Energy and atmosphere
• Optimise energy performance
• Renewable energies
• Improve refrigerant management
• Measure and verify
• Green energy
• Protect the ozone layer
Materials and resources
• Reuse buildings
• Management of construction waste
• Reuse of materials
• Recycled content
• Regional materials
• Certified wood
Quality of interior environments
• CO2 checks
• Increased ventilation
• Interior air quality management plan
• Low-emission materials
• Control of interior sources of chemical emissions and pollutants
• System control by occupants
• Thermal comfort
• Natural light and views
Innovation and design process
• Innovation in Design (management system for energy efficiency and reduction of environmental pollutants)
• LEED accredited professional
BREEAM certification (Building Research Establishment Environmental Assessment) evaluates the performance of buildings in terms of the management system, energy, health, well-being, pollution, transport, ground use, biodiversity, materials and water. Points are attributed on each of these aspects according to the performance levels attained. A weighting system consolidates these scores to obtain an overall final score. This score is awarded in the form of a certificate and can then be used for promotional purposes.
The method was developed in the UK to assist building industry professionals to understand and reduce the environmental impact of buildings at each phase of the construction process. Using this method, the Building Research Establishment (BRE) is capable of measuring the impact of specific construction materials in order to produce environmental projects reflecting their performance. It enables environmental profiles to be created for each material used in the construction, based on a life cycle assessment.
LEED and BREEAM certificate systems both use a scoring system. This feature is not used in HEQ certification, yet it enables the comparison of buildings in terms of sustainable development (green building) and takes into account the performance achieved in assessing the value of the property in question.
SUSTAINABLE DEVELOPMENT AND THE ENVIRONMENTAL FOOTPRINT
is based on three essential principles:
The need to reason in terms of sustainable development also affects concerns about the drift in the greenhouse effect and climate change. Sustainable development is not a temporary fad, today it is an imperious necessity and an economic reality that an increasing number of local authorities and businesses are starting to take into account in their strategies and actions.
The construction sector is at the heart of sustainable development. A large number of stakeholders are involved in construction activities: Project managers, project owners, industrials, service providers and institutional bodies work together on a joint project: The sustainable construction and management of our heritage. Eco-construction or green building is the ideal solution for sustainable management. Effectively, the construction of a building has direct and indirect impacts on the environment at all phases in its life cycle. Among these: Use of materials, product transport, building commissioning, use of the building (operation, impacts on current use, maintenance, renovation) and end of life waste (reuse, recycling and energy production).
The environmental footprint is a tool used to evaluate the productive surface required by a population to satisfy its consumption of resources and its waste absorption needs. It is a measurement of the pressure that humans put on nature, so that we can evaluate the influence we each have on the environment. It offers each of us the chance to assess our impact on the planet and to reduce our consumption of resources and our production of waste, so as to reduce our footprint and act in favour of sustainable development.
On a world level, humankind’s environmental footprint is an estimation of the biologically productive land or sea surface required to satisfy all our needs. According to the world’s leading conservation organization, WWF, in its 2010 report, Humankind uses the equivalent of a planet and a half to satisfy its needs. The Earth has exceeded its bio-capacity by 50%. To deal with the most urgent challenges, actions must be taken to reduce our environmental footprint and enable sustainable development. The following actions are recommended:
• Increase the number of protected zones by 15% in environmentally-sensitive areas
• Participate in sustainable management of forests. According to the H1 resolution (Helsinki, 1993), this is the management and use of forests and wooded terrains, in such a way and intensity that they are able to maintain their biological diversity, their productivity, their regenerative capacity and their vitality. Such a management approach must preserve the ability to satisfy both now and in the future, the environmental, economic and social functions on a local, national and global level. The rational management of forests must not cause harm to other ecosystems.
• Stop excessive consumption of water and the segmentation of fresh water ecosystems
• Eliminate over-fishing and destructive fishing practices (loss of edible fish, destruction of coral reefs, reduction of the diversity and richness of species)
• Invest in bio-capacity
• Promote biodiversity and services rendered by ecosystems
• Solve the problems of priorities between food and energy, generated by agri-fuels
• Pay attention to the problems raised by allocating land and planning land use
• Share limited natural resources
GREEN BUILDING – GREEN INSTALLATIONS
General matters concerning electrical panels
Electrical panels can improve energy performance in a home and thereby contribute to sustainable development and the green building approach. In light of its weight in energy consumption, building energy use is a major concern. Innovative solutions now exist to compensate reactive energy and measure building consumption.
The innovative offers brought out by the Legrand group concern the whole electrical panel. Everything from the installation head, to custom equipment boxes is available. As the electrical panel is the core of the