What are the best renovation scenarios in terms of environmental impact and costs for office buildings, based on a life-cycle analysis? Insights from Brussels case studies

Details

Supervisors

Contino, Francesco

Faculty

Ecole polytechnique de Louvain

Degree label

Master [120] : ingénieur civil des constructions, à finalité spécialisée

Abstract

enBuilding energy retrofitting represents a key lever for reducing greenhouse gas emissions and resource consumption in the construction sector, particularly in regions with an ageing building stock. In the context of increasingly stringent European and regional climate objectives, renovation strategies must be assessed not only in terms of operational energy performance, but also with regard to their long-term environmental and economic implications. This study investigates the environmental and financial performance of renovation strategies for office buildings in the Brussels-Capital Region using a combined Life Cycle Assessment (LCA) and Life Cycle Costing (LCC) framework. The analysis is based on the MMG methodology implemented in the Belgian LCA tool TOTEM, which enables a comprehensive evaluation of both embodied and operational impacts over a reference study period of 60 years. Environmental impacts are aggregated and expressed in Environmental Points (Pt), allowing a multi-criteria comparison of renovation options. The research relies on a real office-building case provided through an energy audit and develops three representative building variants with identical geometry but differing initial energy performance levels. Renovation measures are first assessed individually at the level of the building envelope and technical systems, and subsequently combined into coherent renovation scenarios. These scenarios are evaluated with respect to environmental performance, global costs, primary energy demand, and CO₂ emissions, and are further compared to the energy reduction pathway for office buildings in Belgium using the CRREM framework. The results highlight the need for a life-cycle perspective, showing that strategies optimized only for operational performance can result in higher embodied environmental impacts. This integrated assessment offers context-specific guidance for sustainable renovation decisions in the Brussels office-building stock.