Life Cycle Assessment (LCA) and Life Cycle Costing (LCC) procedures are usually employed during the different building design phases. The first one is mainly related to the environment protection, while the second to the costs control and optimization. This paper aims to define a procedure to "translate" LCA results into an economic evaluation, typical of LCC. The goal is to support the decision-making process in the early-design phase for providing design guidance and monitoring, effectively and timely. This approach can lead to a comparison and choice among different structural technological solutions by focusing both on environmental impacts and on economic costs. LCA and LCC analyses have been carried out evaluating some construction solutions for residential buildings, considering the economic consequence of environmental impact (monetization of carbon emission). This article presents two methods: the first suggests a quantification from an economic point of view the carbon emission during the life cycle of building components through a "carbon tax"; the second one evaluates the "eco-cost" as a Virtual Pollution Prevention Cost (VPPC). Finally, the two methods were applied and compared on a case study, in order to define the possible outcomes on the building construction sector and on public policies.