Introduction

We are currently 6 billions of people living on this planet. Less than 20% of these people live on 80% of the natural resources. Our way of living in the rich part of the world is not at all sustainable. We use resources that should be shared among all people both living now and in the future. If all humans on earth would live with the same material standard as we do in the OECD countries, 12 globes would be needed today! And we only have one globe!

Our way of living influences the natural environment and the conditions for life on earth. We are cutting of the branch that we are sitting on. Air pollution, climatic changes, nutrification, acidification and a severe degradation and depletion of natural resources are some important reasons to find new ways to sustain on earth. New substances are introduced in the flows in society like chemicals, and others are introduced in larger amounts than ever before like hormones. What will happen in case of a large nuclear accident or what will happen when new mutated plants and substances spread, nobody knows today. These facts seem to be a good reason to start to think of another way of living.

Sustainable development

Sustainability has been on the political agenda in most industrialised countries since the UN conference on environment and development in Rio 1992. On this conference a contract was signed among the countries on earth called Agenda 21. This documents is based on a democratic process on a local level where all humans on earth would join in the work for a sustainable development.

The World Commission on Environment and Development (WCED, 1987, Our Common Future) defined the sustainability concept in which they emphasised that a sustainable society should be able to sustain ecological, economical and socio-cultural systems. This three-legged basic concept for sustainability is based on equity between nations, generations and individuals. As defined by the WCDE, sustainable development declares the right for all humans now living and in the future to be able to satisfy their basic needs.

The definition given by WCED is rather vague and open for interpretation. To implement the work with sustainability there is a need for further developed definitions. In Europe the factor 10 club was formed on the initiative by the German Wuppertal institute. Factor 10 is accepted as concept for sustainable development among several European countries including Sweden. The idea is that the industrialised countries should in 30 to 50 years render their use of resources and decrease their total impact on nature ten times, a factor 10, maintaining or increasing contemporary living standards.

Other models to measure a sustainable development are, for example Ecological Footprints, a model developed by Matthias Wackernagel and William Rees. A "footprint" is the total area of land and water needed to support a nation with renewable resources.

The Wuppertal institute has made a study of the Environmental Space of Europe at the request of Friends of the Earth Europe. Environmental space is defined as the resources that can be used by the individuals in one nation, without risking the supply for other nations, now and in the future.

The natural step organisation.

The Swedish organisation The Natural Step has developed four socio-ecological principles for achieving a sustainable development based on the laws of thermodynamics. Their conclusion was that humans, just as nature, do not tolerate systematically increasing concentrations of substances in the ecosphere.

1. Substances extracted from the litho sphere must not systematically accumulate in the ecosphere.
2. Society-produced substances must not systematically accumulate in the ecosphere.
3. The physical conditions for production and diversity within the ecosphere must not systematically be deteriorated.
4. The use of resources must be efficient and just with respect to meeting human needs.

The four socio-ecological principles gives a framework for a sustainable society and illustrate what at least has to be fulfilled, if not nature and the natural resources will be systematically annihilated.  

Environmental impact from buildings.

Buildings are important features in our lives. We actually spend most of our time indoors, if living in colder climates. And buildings are an important part of our cultural heritage.

Buildings and the building sector contribute to a large part of society's environmental load regarding resource use, ecological impacts and human health impacts. In Europe about 40% of the energy use is contributed to the building sector where heating of houses will have a big part. A large part of society's material use and waste production comes from building related activities, as well as transports

Researchers at the Worldwatch Insitute has presented a compilation of the environmental impact caused by building at a global level:

To work with environmental issues in buildings is not an easy task due to several factors:

1. A building has a comparative long lifetime.
2. A building will interfere with nature during all phases of its lifetime from resource extraction, planning, construction, user phase and final demolition.
3. A building is a complex product involving many different materials and component that interact.
4. The building process involves many actors and the environmental responsibility is not clear.

Other important factors about environmental impact from buildings are that more than 85% of the energy will be used during the user phase. The user phase will have a relatively large part of the buildings environmental impact. This means that users habits and management of buildings will be of a great importance.

How to make better buildings?

The first question to ask is if a new building really is needed or if an old building could be reused and altered to fit new demands.

If a new building is the only possible solution there are some factors that we should think of:

Time:

Time is an important factor that should be considered. We make decisions about a house today, but the house will stand for 30 - 300 years! Better think first!

Different part of a house have different lifetime. Make it possible to change different systems within the house without disturbing the rest. A useful model of the different layers in a house is developed by architects Frank Duffy and Stewart Brand.

The site is eternal. A structure is in fact the house, and should stand for a long time and thus be of good quality. Here you could spend some money. The skin, the façade will change every 20 - 30 year, and the services even more often. And the most movable part of the house, the furniture and decoration will change rapidly.

Build with flexibility in mind! Flexibility is valuable, and like exergy compared to entropy, a free potential for change.

Think of architectural quality; build rooms that are pleasant to stay in. These are the houses that will last long!

Resources:

Limit the use of resources like energy, water and materials with the strategy:

1. do I need it?
2. if I need it use a minimum
3. use environmental friendly alternatives that comes from renewable resources.

An example: With this strategy you should first ask if your house needs a heating system and electricity. If it does, (even in Sweden well insulated houses are built without heating system!) try to minimise the energy use by good insulation, windows with a good U-value, etc. (If you insulate your house don't forget the ventilation system!) Use renewable and environmental friendly materials, for instance, there are insulation materials like straw, wool, and recycled paper. Use materials which are produced using little energy! And maybe the most important, use a renewable energy resource like solar and wind energy, and biomass. (Think of the CO2 production and the global heating!)

Make a maximum use of "free" energy like human heat,

like human heat, heat from lamps etc, and make use of passive solar gain through a good position of the house in relation of the sun. Temperature zoning in the house will place spaces you use less to the north and places where you pass the day on the sunny side.

An adequate form of the house will make better use of passive solar energy, and minimise effect from wind and rain. Houses can be built partly under earth for example. They can have small windows to the north and big to the south etc. The house should be adapted to the specific climate of the site. This is important!

Think of the end of the house already when you design it!

Use a design that is possible to dismantle and materials possible to recycle. Use screws instead of nails and glue. Use lime mortar instead of cement in brickwork. Avoid composite materials, and do not use new materials that we have no certain fact about. This could be built-in future environmental problems! When choosing materials also consider maintenance and cleaning. A material can have a low environmental impact in itself, but it might need heavy cleaning procedures using chemicals, or need a lot of maintenance, or have a short lifetime etc.

Design for an environmental friendly and healthy life-style:

A large part of the environmental impact comes from the users phase, and with a good design we can help the inhabitants to lead an "ecological life".

An ecological lifestyle would include to close the eco-cycles in nature, for example to bring nutriment to the earth through compost of biological refuse, and by using compost toilets or other toilet system with biodegradable functions. The compost can be used as fertiliser on cultivation or trees (if a lot of hormones or heavy metals can be found in the compost). Water from showers, dishes and toilets can be cleaned in earth or in water. Then the inhabitants should be sure not use violent products like chlorine, or non-biodegradable washing powders and soaps!

Minimise energy use by offering energy and electricity saving equipment.

Why not a wooden stove for cooking! And use blankets to finish the cooking time for the rice, using the heat that is already in the casserole.

Minimise the use of fresh water

through water saving showerheads, taps, and toilets. Rainwater or used "grey-water" (from showers and dishes) to flush toilets. Rainwater can also be used for washing clothes, and as this water is softer less detergent will be needed!

In the garden provide for a maximum of rainwater falling into the ground. The water is needed on the spot! Avoid asphalt and other non-permeable surfaces. Use a rainwater barrel to keep rainwater for gardening.

Other nice parts of an ecological lifestyle could be grow your own vegetables and to store them in an earth cellar.

All these function should be thought of in the design. There should be enough places for waste separation and for compost bins. There should be places to dry your laundry, to store your bike, to store all the woollen pullovers and socks that you will need in wintertime, etc.

For health reasons, do not use materials indoor that give emissions that can cause allergic reactions. Use "natural" materials that also give a nice atmosphere according your own taste, like wood and tiles.

 

Sum up:

It is nice to live in an environmentally designed house, and it will probably use less resources and contribute on the long term for a sustainable development. But don't forget that one trip to Mallorca with the family in plane might use more energy than your house in one year. And that a big part of the environmental pollution comes from the use of private cars! And what about those fruits from South-America?

Full article of Dr. Paula Femenias: clic here