Environmental profile of green roof material in different locations in Spain: Life Cycle Assessment and optimization

Abstract

The building construction industry consumes 40% of the materials entering the global economy and generates 40–50% of the global output of greenhouse gases and agents of acid rain. Thus, energy building consumption minimization became one of the basic principles of the European Environmental Legislation and Strategy. [1] Considering this, the benefits provided by green roofs appear to make them a good option. They reduce thermal fluctuation on the outer roof surface and increase thermal capacity; help to mitigate air pollution; reduce urban heat island effect and noise propagation; reduce runoff peaks of rainfall events; and increase biodiversity. [2-5] The use of green roofs has increased noticeably in recent years in many countries, but relevant up-to-date environmental data is needed to allow the environmental comparison of green roofs with conventional solutions. This will help us to assess their behaviour and analyse if, just because they have vegetation, we can call them “ecological roofs”. There are examples of Life Cycle Assessment (LCA) studies of some construction materials, however no comprehensive Life Cycle Inventory (LCI) data for green roofs is available in the literature. The scope of the study is to deepen the knowledge of green roofs by studying the environmental profile of the materials used to build them, and how their adaptation to climatic conditions affects their environmental impact. To do so, LCA methodology has been used to study the environmental profile of the materials.