The choice between different materials and constructive systems can influence significantly the environmental impact and cost of construction. In this context, four constructive systems used in Portugal were studied: one conventional - composed by brick walls and steel reinforced post and beam concrete slabs; and three non-conventional - light steel framing (LSF); wood frame (WF); and insulation concrete form (ICF). Using a case study based on a contemporary Portuguese typical dwelling, some environmental impact indicators, as well as the weight and the economic cost of these solutions were evaluated.