Methodological discussion and piloting of Life Cycle Assessment – LCA-based environmental indicators for eco-efficiency of Brazilian building materials

Resumen

Water consumption, energy consumption and CO2 emission are indicators common to many industry sectors. Less common - but relevant - indicators are the non-renewable content and the Volatile Organic Compounds emissions. Life Cycle Assessment – LCA can support calculations of these indicators, but is still embryonic in Brazil. This paper main goals are (i) proposing a set of LCA-based indicators to assess eco-efficiency of building materials per unit of built area, (ii) analyzing differences between embodied CO2 and embodied CO2eq. of Brazilian building materials, and (iii) verifying calculation feasibility of proposed indicators based upon four case studies. Data for materials/components production cycle modeling were collected from national literature or adapted from SimaPro 7.3 built-in Ecoinvent database. Results showed that, for the studied building typologies, 80% of the total embodied energy were related to cement, steel rebar, ceramic brick, sawn timber and plywood, while the ranking for the embodied CO2 changed, showing that 89% of the total value was related to cement, ceramic brick, steel rebar, PVC tubes and conduits. Therefore, a core database for about ten materials provides a reasonable description of the building embodied energy and CO2 profile, corresponding to 98%, in both cases, of total values. For cement and concrete, partial replacement of clinker by ground granulated blast furnace slag brought substantial reductions of proposed indicators. Proposed further research is expected to contribute to constitute a Lyfe Cycle Indicators – LCI database that enables the use of the proposed metrics, and reinforces the advantages of using LCA as a decision-making tool in the national building sector.