LCA: Building and the Ecosystem
Simplified Environmental Model

A simplified model of the environment for building applications should be composed of two parts: a medium oriented description and an effect oriented description

A) Medium oriented description:
The medium oriented description generally distinguishes 6 compartments of the environment :

1- Soil
The soil is a complex system of mineral and organic, liquid, solid and gaseous component which fulfills many functions : - basis for plant production - regulator of the water circuit and for material transformations - filter for solid and dissolved particles in water The two main impacts of building and other human activity are : - erosion - sealing of soil (buildings, streets, parking etc.) the following substances are considered as pollution indicators : Ca - calcium Hg - mercury Pb - lead Ni - nickel Cu - copper

2. Water
Water is used in many ways : - drinking water - process water - cooling water water can also serve as transport and energy storage medium. Water is in constant circulation and phase change (liquid-gaseous-solid) in nature. Non desired materials can be contained and transported by water. water quality can change. The basic human impacts are : - pollution of surface and ground water - raise in temperature of water The following substances are considered as pollution indicators for water : Water: DOC BSB5 organic chlorides Fe - iron Suspended matter Oils and fats Hg - mercury Cyanides

3 Air and climate
Soil is immobile, water can only follow gravity laws whereas air can transport pollutants rapidly over large distances. Air is composition of many gases which has different effects on other compartments of nature. Only small differences in composition are tolerated without immediate effects on other systems. The enthalpy of air is responsible for the weather and the climate in a large sense. Together with pollution it influences the urban microclimate in a deceive way. Noise in all forms can also be considered as a form of air pollution The following substances are considered as pollution indicators for air pollution: CO - carbon monoxide NOx - oxides of nitrogen Dust and soot Zn - zinc CO2 - carbon dioxide CFC -chloro-fluoro-carbons Ammonia Ca calcium SO2 -sulfur dioxide CH4 - methane Pb - lead Aldehydes

4 Flora
The flora or vegetation comprises all plants in a given area. Human activities influence vegetation in many ways (agriculture, building etc.). Building effects are principally the destruction of biotopes, the sealing of the soil and the air and water pollution. The three basic impacts are : - reduction of species - massification of species - growth damage The main long term problem of all environmental impact through human activity is the reduction of biodiversity (as an insurance for life itself)

5 Fauna
The human activities influence the fauna in a very similar way.

6. The image of the environment
For humans one of the first and most powerful illustrations of environmental damage is the image of the landscape. The destruction of this image is mainly the result of : - punctual contrast through equipment's and buildings - reduction of complexity through the sprawl of buildings The natural environment which is important for relaxation is destroyed, but it is difficult to quantify these destruction's exempt by asking people how much they would agree to pay for their maintenance.

B) Effect oriented description:

The generally recognized, non desirable, environmental effects are: