Connecting People and Ideas . Proceedings of EURO ELECS 2015 . Guimarães . Portugal . ISBN 978Ͳ989Ͳ96543Ͳ8Ͳ9 Study of the of the concept of community buildings and its importance for Land Use Efficiency José Amarilio Barbosa University of Minho, School of Engineering, Department of Civil Engineering, Guimarães, Portugal jabarbosa@civil.uminho.pt Catarina Araújo University of Minho, School of Engineering, Department of Civil Engineering, Guimarães, Portugal cba@civil.uminho.pt Luís Bragança University of Minho, School of Engineering, Department of Civil Engineering, Guimarães, Portugal braganca@civil.uminho.pt Ricardo Mateus University of Minho, School of Engineering, Department of Civil Engineering, Guimarães, Portugal ricardomateus@civil.uminho.pt ABSTRACT: Nowadays cities are facing several environmental problems due to the population migration to urban areas, which is causing urban sprawl. This way, it is very important to define solutions to improve Land Use Efficiency (LUE). This article proposes the use of community buildings features as a solution to increase land use efficiency. Community buildings consider the design of shared building spaces to reduce the floor area of buildings. This work tests the performance of some caseͲstudy buildings regarding LUE to analyse its possible pros and cons. A quantifiable method is used to assess buildings’ LUE, which considers the number of occupants, the gross floor area, the functional area, the implantation area and the allotment area. Buildings with higher values for this index have reduced environmental impacts because they use less construction materials, produce less construction and demolition wastes and require less energy for building operation. The results showed that the use of community building features can increase Land Use Efficiency of buildings. Keywords: land use efficiency; building performance; sustainable buildings; community buildings 1 INTRODUCTION Nowadays societies are responsible for many environmental and societal problems resulting from a mixture of population growth, the movement to urban areas and the increase of consumerism and of the standard of living of the population. With a world population of about 7.3 billion persons, the UN predicts that nowadays, about 3.8 billion already live in cities. By the year 2030, these figures are predicted to evolve to 5 billion people living in cities out of 8.4 billion (United Nations, 2014) (Figure 1). 1347