Life cycle carbon emissions assessment of a multifamily residential building in Brasília-DF

comparison between design data and real site data

Abstract

This study quantifies the embodied carbon emissions (EC) of a high-end multifamily residential building located in Brasília, Brazil. Using a Life Cycle Assessment (LCA) approach with a cradle-to-construction-site scope, the inventory was developed based on two material quantitative sources: design-based (DD) estimates and actual construction site data (SD), enabling comparison between estimated and actual material consumption emissions. The results indicate total EC of 402.63 kgCO₂eq/m² based on construction data. The comparison between design and construction shows an increase of up to 20%, associated with differences in quantities, omission of materials in the initial budget, and design changes. The sensitivity analysis indicates systematically higher EC when using SD, with variations ranging from 10% to 20%. This range is interpreted as an initial exploratory value, without normative character, intended for preliminary uncertainty assessments. The study contributes by addressing a building typology still underexplored in Brazil and by proposing a first approximation to incorporate additional emissions from construction activities and design changes. Finally, it highlights that the use of real data is essential for accurate assessments and for establishing reliable carbon reduction targets in the construction sector.