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Design tools in the planning process |
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Research efforts and national energy policies have encouraged energy conservation and renewable energy technologies successfully, allowing the reduction of specific end-energy consumption. Since the oil crisis, the general objective of energy saving has shifted from the shortage issue to a more general objective of environmental protection. There is a need for scientific methods to assess the environmental impact of a building allowing one to choose among different low energy and solar technologies. Existing methods including labels, declarations of content, positive and negative lists, and qualitative appreciations are not transparent and they are often only suited for a limited part of the design and building process. They furthermore do not include a life cycle perspective. The inventory of mass and energy flows during the life cycle of a product is one generally accepted basis for the environmental impact evaluation. 
The method of Life cycle assessment (LCA) has been developed by scientific associations like SETAC and has been widely accepted by industry and standardization boards (ISO). The complete LCA method has 5 steps. The steps «classification» and «evaluation» are called Life cycle impact assessment (LCIA).
LCA, which was mainly developed for industrial products with current life times of weeks and months had to been adapted to the building industry. Buildings are produced as one-of-a-kind products, their lifetime may be up to hundreds of years, they include a large and still growing number of materials, and their design process is complex involving many actors with often contradicting targets. The system limits in time and in space have been defined and models for the simulation of the life cycle (maintenance, refurbishment) have been developed. Specific functional units (adapted to the different steps in planning from design brief through the design and construction process to facility management ) have been defined. The main effect-oriented evaluation methods (based on emissions) were taken from the current methods developed inside the SETAC group by CML and others. Additional methods had to added to take into account resource consumption. One of the principal shortcomings of all of the existing methods is the lack of a coherent database with precombustion data, building materials and building processes. A new consistent data base has been established in REGENER and other projects including precombustion, transport and disposal emissions from the process analysis of the Swiss ECOINVENT. Inventories for more than 150 buildings materials have been established together with industry. All data are from the last 3 years and older literature values are no longer used. This database resulting from the collaboration of industry and research, funded by the EC, the German Umweltstiftung and the Swiss Department of Energy, is public. The detailed life cycle simulation of buildings allows the development of a first series of design tools. Thus life cycle assessment provides a scientific base in the construction field. There are however still many open questions for research : What are the correlations between the existing and new evaluation criteria, do multicriteria methods allow one to handle the complexity of several evaluation criteria, what are the transfer functions for waste, how to integrate the resource consumption and possible recycling, how to appreciate the impact on the local environment (town and regional planning), indoor air pollution (sick building syndrome), worker protection, user protection during refurbishment. This research effort will only be successful if it is based on a close collaboration of industry, research institutions and designers. |
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Design tools in the planning process |
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Design tools are considered to be instruments intended as aids in the planning process. In order to be as effective as possible they must relate to the problems confronting the actors involved and to the way in which external knowledge and information is used to tackle these problems. The design process of buildings is not linear. Design tools for LCA must be tailored to the main steps in the decision process. The question in the design brief is : do we need a new building or can we transform an existing building. In the building design the question are how does a design alternative relate to functional performance, costs, energy consumption and environmental impact. In the construction stage the optimal choice of building materials and building processes in relation to the ecotoxicological and humantoxilogical requirements are critical. At the same time the functional unit varies from very general m² use surface to detailled building specification (pouring 1 m3 of concrete). 
Existing tools, theories on designing and decision making, and consulting practice have been analysed in order to study the relations between phases and actors in the planning process and to derive a general scheme for design tools. Input and output have also been studied and the result of this work is a design toolbox, useful to any tool developer. Three methods try to taking into account this procedure. They differ in the determination of local system limits, national conditions of building practice, and performance specification .
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Regional applications |
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Regional administrations were contacted for possible applications of the Regener methods and concepts. A simplified technology assessment method is proposed in order to select the appropriate renewable energy technologies according to a regional context. Demonstration projects are under way or planned in order to disseminate ecological construction concepts and methods among architects. For instance, a brief has been written for a highschool near Paris, in which environmental quality constitutes 179 supplementary criteria. This project will offer a demonstration example of the approach. The Umbria Region will attempt to use the Regener methods on a retrofitting programme concerning 8 buildings located in eight different towns of the region, aiming at the application of the catalogue of energy conservation and substitution measures of the Umbria Energy Plan (TEP Project). First sensitivity studies have been performed to illustrate a few possible applications of the LCA method. They show that environmental performance is the result of a good design but also of appropriate occupant behaviour. Comprehensive occupant information must thus be delivered with a building. The method can also be applied when choosing a construction site, accounting for local networks (energy, water, waste management, transportation) and climatic conditions. Comite 21, created in France after the Rio Conference, is planning an exhibition in Paris on ecological housing. An international architecture competition was organized, and the winner was a group of Finnish and French architects. A very simple tool has been derived from the LCA methodology, allowing anyone to evaluate the environmental consequences of various actions : bioclimatic versus standard design, choice of the heating energy (gas, fuel, electricity or wood) and the temperature set point, waste sorting, water management, transportation. This will also constitute a good opportunity to disseminate the results of the REGENER project. Future application of this project in the building sector could be to assess the environmental benefit of specific solar techniques (e.g. transparent insulation) or renewable energy sources (e.g. wood fuel). To view and print, first download the Acrobat Reader appropriate to your platform.
Regener Summary
Regener Report 1, Environmental assessment at the local level
Regener Report 2, Application of life cycle analysis to buidings
Regener Report 3, Integration of environmental assessment in the building design process
Regener Report 4, Application of LCA by target groups |
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Articles |
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Peuportier (B.), Kohler (N.), Boonstra (C.) 1997. "European project REGENER, life cycle analysis of buildings". 2nd International Conference "Buildings and the environment", Paris, June 1997. |
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Contact |
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Bruno PEUPORTIER |
INFORMATION DATA SHEET
Goal definition