The aim of sustainable construction is to lessen the environmental impact of a building throughout its life cycle. It gives consideration to the choice of materials used, the building process, how the property affects the occupier and what might happen to the building when it is demolished. By using traditional skills, good management and renewable resources, sustainable building makes the foundations of modern living both ethically and environmentally sound.
Building and construction has an unhealthy appetite for energy and resources. 7 per cent of UK primary energy demand and 9 per cent of CO2 production is used for construction materials. Domestic heating, lighting and cooking is responsible for around 30 per cent of UK energy demand and 30 per cent of CO2 emissions. Around 115,000kWh of embodied energy are used in the materials, transportation and building of a typical three bedroom masonry house, but this is just 5 per cent of the energy needed to power the house during its life. By getting the design right, the potential for energy and resource savings is massive: a low energy timber frame house can halve both figures easily.
The 7.5 tonnes of CO2 per year created by an average house could be cut by 50 per cent if simple and established energy conservation techniques were adopted. Government forecasts of climate change (higher winds, higher temperatures and increased flooding) are already evident in our weather, so CO2 reduction must be a priority.
A sustainable balance between the reasonable requirements of people and nature lies at the heart of environmentconscious building. We must take care of the natural world and use its resources wisely because we are totally dependent on it for our survival. Quality of life for people comes from a sustainable, fair and healthy society, working in harmony with nature.
Sustainable building is as much a philosophy as it is an art, although the wealth of ideas and opportunities that spring from the concept can stimulate artistic talents that most of us never knew we possessed. It requires us to consider what buildings we use, how we build, how the building affects the environment and what happens when the building is taken down.
Design and construction to sustainable criteria will directly benefit local economies and will reduce transport and environmental costs. Since we live in a changing world, it is sensible to design buildings that can be recycled, so that materials and foundations can be easily reused and land is not degraded or polluted.
The facts about CO2 emissions and the greenhouse effect are well known. Vast amounts of energy are consumed in the production of building materials and during the lifetime of any building. Select materials and products that use the least energy in manufacture (natural or near natural) and can be re-used, or are already recycled. Ensure buildings are insulated to the highest possible standards, as this will reduce fuel bills. When designing a new building take advantage of the sun’s free energy. Site orientation and the scrupulous use of glazing can make the best of passive solar energy. Where possible investigate and consider using alternative, renewable forms of energy such as solar, biofuels and power from wind and water.
The effect of CFCs (chlorofluorocarbons) and HCFCs (hydrochlorofluorocarbons) on the ozone layer has been recognised for many years, and the damage associated with CFC emissions has been addressed by international governmental agreements. However, some insulations still use HCFCs. Although these have a lower ozone depletion potential, they carry a very high global warming potential. Alternatives such as cellulose, wool, cork and foamed glass are available and should be considered.
More details on the use of CFCs and HCFCs in the home and their effects on the environment can be found in the section on fridges and freezers.
It is well known that exposure to chemicals can cause damage to the environment and human health. Hazardous chemicals are found in many products such as timber preservatives, paint and wood stains, although there are an increasing number of natural alternatives available. In particular, there is still excessive emphasis on treating timbers. For example, many banks, building societies and local authorities insist on extensive chemical treatment of existing woodworm when providing grants or loans. Many of the chemicals approved for use in this country have been banned or restricted overseas.
Within the fabric of a new building there is generally no need to treat sound timber against infestation and rot. Insect infestation and dry or wet rot in older properties can often be dealt with by changing the environmental conditions in the building, through adjusting humidity levels and temperature. There are companies that offer surveys in this respect, including necessary guarantees to satisfy third parties. If action is considered necessary then a boron treatment should be used. Boron is considered to be the least toxic of treatments.
Other issues related to health include the over-use of plastics in buildings, particularly PVC. Hazardous fumes result when PVC is burnt, but more recently it has been suggested that phthalates migrate from the plastic into the atmosphere. There is increasing scientific evidence to suggest that exposure to some of these chemicals may cause widespread problems including immune system damage and cancer, which has prompted Greenpeace to run a campaign highlighting the problems of PVC. Evidence also indicates that some phthalates can disrupt the hormone system. Alternative materials to replace PVC include copper, stainless steel, iron and HDPE (for water pipes and drainage), timber (for cladding and sheeting), timber and aluminium (for windows and doors), clay (for drainage), timber and linoleum (for flooring) and rubber (for electrical cable).
Water and waste
There is a greater emphasis today on avoiding pollution of water supplies and conserving water. Reed bed sewage systems are an innovative and effective way of disposing of waste in a manner that is ecologically sound. WCs are available which use less water, but the ultimate green loo is the composting toilet, which uses no water, evaporates the urine and turns sewage into a valuable source of nutrients for the garden. There are also urine-separating toilets which isolate urine from faeces. The urine can then be piped onto hay or straw bales to produce nitrogen-rich compost
Rainwater harvesting systems are available, which save and store rainwater from roofs for flushing toilets, washing and other household chores.
As more and more land is developed it is important to conserve and encourage wildlife. Trees, hedgerows and ponds can be carefully protected and retained during building operations. Consider setting aside small areas of land as wild nature areas, or establishing a new pond to promote biodiversity. It is also possible to plant indigenous trees and hedgerows, and use dry stone walling to provide a habitat for animals and insects.
Good design is an integral part of sustainable building. Make the structure easily adaptable, for example by using demountable partitions so that the internal layout can be altered when necessary. Design also for health and comfort, to provide optimum levels of daylight, sunlight, temperature and fresh air.
The cost of any building depends on the design. However, costs for sustainable building can be comparable. In the future they may even be cheaper as the concept of sustainability moves into the mainstream and the economics of scale come into play. Sustainable buildings give added value and avoid the hidden costs, in terms of health and pollution, associated with conventional buildings. Many eco-products are currently manufactured on a smaller scale and can therefore be more expensive or involve higher transport costs.
Selection of ecological building materials
Approximate figures for embodied energy (the energy used in a material’s manufacture or mining) allow us to compare the energy costs of various materials, and reveal the advantages of recycling and of using easily won, natural materials. For example, the production of fibreglass can require approx 15 times more energy than recycled cellulose insulation.
The way forward
Sustainable building needs to be more widely promoted. Ideally, it should be economical, supported by the government and widely accepted as the norm. Building regulations should ensure that the relevant minimum standards are met, such as increased insulation, as we currently fall way behind our European counterparts in this area. The skills shortage problem must also be addressed, and traditional skills (which tend to be more sustainable) must be re-taught.
Some non-renewable fuels are becoming cheaper (in monetary terms) despite their hidden environmental costs, so much more support needs to be given to the renewable energy sector and VAT reduced or removed from this area. It would be helpful if a standard design could be developed for sustainable building, which would encourage the volume builders to embrace this form of construction. This would also make it easier to formulate suitable training programmes to deal with the skills shortage.
People can help by being demanding, and refusing to accept the standard products on offer. We can demand higher levels of energy conservation, knowing that the building will be better for the environment and at the same time benefit the individual with lower fuel bills and higher living standards. We can also be more demanding over what type of materials are used in the building. All of us should bear in mind the high levels of environmental degradation that are involved in many standard building products, and also take into account the ethicality of their production. Tŷ-Mawr Lime sells a large range of ecological building products to clients across the UK and has passed an ethicality audit by The Ethical Company Organisation. See www.lime.org.uk for further details.
- The Association for Environment Conscious Building (AECB) can supply more information on green architecture and sustainable building. It has a database of builders who are registered members of the Association, and began the CarbonLite programme for promoting ‘carbon liberate’ design. It also runs a training scheme, SussEd (Sustainable Skills and Education), which teaches sustainable building skills for the construction industry. For more information about this organisation send an A4 SAE (73p) to AECB, PO Box 32, Llandysul, Carmarthenshire SA44 5ZA, email firstname.lastname@example.org, visit their website at www.aecb.net or phone 0845 456 9773
The Good Shopping Guide would like to thank John Shore (AA Dipl) for his help in compiling this section.
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