Building Shape that Promotes Sustainable Architecture. Evaluation of the Indicative Factors and Its Relation with the Construction Costs

Abstract

The energy that the building sector consume including both, the production and operation of buildings are directly proportional to the shape and the thermo-physical properties of the building envelope. The shapes that the architect decides on influences the costs of the construction as well as the energy demands for the life-cycle of the building. The present paper analyse four factors indicated by the bibliography to measure efficiency of the shape of the building. Theserelate different building variables: Envelope Area of Building (Ae), Conditioned Volume (Vc), Floor Area of Building (Ac), Perimeter of Building (Pb). The four factors studied are: Compactness Factor (Ae/Vc); Characteristic Length (Vc/Ae); Compactness Index (Pb/Pc) and Shape Factor (Ae/Ac). This paper also explores the relationship between the SF (shapefactor) and the cost of the construction of the building in relation to floor area, where a high degree of correlation is found, high R2 (<0.89). Therefore, it can be concluded that SF optimizes decisions concerning the shape of building in order to reach lower surface areas (compatible with an aesthetic, harmonic and functional design) that yield the lowest economic and energetic costs of construction.