ARCHITECTURAL DESIGN AND CONSTRUCTION COSTS, TOOLS TOWARDS TERRITORIAL SUSTAINABILITY

misbe2011 Tracking Number 17

This paper is presented in CIB: Management and Innovation Sustainable Built Enviroment 2011, as the study and analysis of the residential model of a rural area from the Iberian Peninsula, specifically applied to the case of the province of Cáceres, in the autonomous region of Extremadura, in Spain. This region, with an eminent rural nature and economic resources traditionally linked to the development of the land, and, specifically, to activities such as livestock breeding and agriculture, has suffered a strong emigration of the population, since the 60’s, towards the most powerful city centres, generally provincial capitals and specifically the capital of the State (Madrid). For years repopulation policies were carried out (such as the Badajoz Plan) reinventing towns out of nowhere, which did not achieve the expected success, maybe because of the lack of roots before the new, maybe because of the roughness of the agricultural and stockbreeding tasks faced with the opportunities in the city. As a result, in the end of the 80’s many towns were practically deserted. In this context, Extremadura became one of the most depressed areas in Spain in the 80’s, therefore being one of the least developed areas in Europe, up to the moment when the entrance in the EU and its help policies started to point at the beginning of a stimulating process of the territorial economy. Following this boost, the autonomous government of Extremadura started helping the promotion of housing in the rural area through a substantial economic help with non-recoverable funds (18.000 EUR) and providing the technical service of the private project commission and the actions management. As a previous condition the property developer –self-developer– is required to hold the ownership of the site and the stay in the dwelling for at least 10 years; the technical conditions of the building are notably regulated, with a limitation of the maximum surface (95 m2 usable) and a list of specifications for the finishing. However, there is freedom in the program, and in general, in the architectural design as opposed to other figures supervised by the administration, such as state subsidized housing, whose design is more restricted. This building typology has achieved an important success during the last fifteen years within this territorial scope, with about 2.800 dwellings, fully occupied, promoted from 2001 to 2008. All this makes this public initiative an interesting answer to the socioeconomic problems of the rural environment, specifically in Extremadura, which has produced an occupation of the territory more polycentrist and a distribution of the natural resources more sustainable. In this context the paper intends to analyse the characterization of this type of dwelling whose success has been the freedom of design and the suitability to the rural environment, so changeable within the different areas of the autonomous region. It is intended to analyse which are the variables of the architectural design that have an influence on the construction cost in an environment of limited economic resources, since the dimensions and qualities of the built product are marked by the subvention’s administrative process. To this end, from a database made up of building projects whose real costs are known, it is intended to establish the links of the different parameters studied through the corresponding functions of statistical analysis. With this study we intend to determine quickly the real cost of construction through the development of a parameterization mathematical model, which will allow to anticipate with rigor and accuracy the economic investment to do with a double purpose: on the one hand, the autodeveloper of the dwelling will be able to control the financing process and, on the other hand, it will make easier for the acting administration to carry out a help policy more suitable for each case. One of the main objectives of this process is constituted by the possibility of establishing, independently of the type of dwelling (subsidized or not), those design variables of higher economic importance, so as to keep an economic control of these parameters, generally geometrical and typological, from the very start of the project. And, in general, a higher optimization of resources in the construction of dwellings in the rural environment from their design is intended. Finally, this study will allow the Administration to carry out a sustainable policy of development in the rural environment of Extremadura, by counting with a better knowledge of the construction costs for this type of dwelling, whose success is important in the process of anchoring the population to the territory.