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Green Building - Environment and climate
THE ENVIRONMENT
Natural resources
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.
Waste treatment
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.
CLIMATE CHANGE
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.
ENVIRONMENTAL QUALITY
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
Presentation
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
Pre-requisites
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
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.
GREEN BUILDING – Ecological construction
GREEN BUILDING – Components
GREEN BUILDING – Environment and climate
GREEN BUILDING – Certifications
SUSTAINABLE DEVELOPMENT AND THE ENVIRONMENTAL FOOTPRINT
GREEN BUILDING – Green installations
GREEN BUILDING – Eco-technologies and practices
GREEN BUILDING – Zero energy home and economic aspects