Characterizing the construction sector’s potential as secondary plastic provider

Licentiatavhandling, 2025

Plastics in the construction sector contribute to negative climate impact and waste generation, highlighting the importance of promoting their circularity. Currently, the construction sector is the largest secondary plastic consumer but achieves only a 25% recycling rate for plastic waste. However, large plastic waste flows and substantial plastic stock in contrast to low plastic waste recycling rate in the construction sector points towards that this sector holds greater potential for sourcing secondary plastics than is currently utilized. This thesis aims to characterize such potential to improve plastic waste management at construction sites of buildings. Three main research objectives are set: identify and characterize plastic products used in building construction, develop a quantification approach to quantify plastic material flows in building construction, and investigate how the characterization and quantification of plastics can be utilized to address barriers to implementing construction plastic circularity. Qualitative research methods involving desk research, literature review and thematic analysis were employed for characterizing construction plastics and identifying and analyzing barriers to implementing construction plastic circularity. A quantitative research design with material flow analysis and case study was utilized to quantify plastic material flows in building construction.  

A plastic product list encompassing 31 types of plastic products made from 17 polymers across 7 product categories uncovers the variety of plastic waste generated by the construction sector. The developed MFA-based approach quantifies plastic material flows in building construction based on product category, polymer type, and building part, presenting the theoretical potential of the construction sector as secondary plastic provider. The circularity of these plastic material flows is however hindered by barriers at different lifecycle stages of construction plastics. The Construction stage faces the highest number and diversity of barriers and “Collection and sorting” being the most complex barrier type. These barriers do not apply to every plastic product. Moreover, of the 83 identified barriers, 13 can be directly addressed or targeted for elimination using quantified plastic material flows as a basis for further analysis. This detailed understanding of the construction sector’s potential as secondary plastic provider enables the evaluation of climate benefits for achieving such potential. Furthermore, it supports the development of evidence-based strategies for improving plastic waste management at construction sites.