A Lean & Green approach for the ecoefficiency assessment on construction sites: description and case study

Lean and Green seeks to increase added value and reduce waste generation, while also improving environmental sustainability performance in production activities. However, no studies were found exploring the potential results by combining Lean and Green with eco-efficiency assessments in the construction sector. Therefore, this paper aimed at proposing and testing a Lean and Green approach in three steps. Step 1 was based on the Value Stream Mapping application to calculate the Value Added of construction activities; step 2 focused on the Life Cycle Assessment of evaluated construction activities, and step 3 performed an eco-efficiency assessment of construction sites to guide decision-makers on selecting more lean and sustainable construction materials and strategies. A case study was developed for a 300m²-house construction considering two build options (reinforced concrete frame vs. light steel frame). The results affirm that light steel framing showed a Value Added 43% higher than the reinforced concrete in step 1, whilst having 8% less Global Warming Potential impacts in step 2. Step 3 concluded that light steel framing was 1.38 times more eco-efficient than the concrete structure. The proposed approach can be suitable for any building system evaluation in terms of construction technologies, materials, and/or production strategies and investigations towards more sustainable production.