The construction sector, known for its extensive use of building materials, significantly contributes to environmental degradation, resource depletion, and waste management challenges. While much attention has been given to creating circular systems in demolition, renovation processes—occurring more frequently due to varying lifespans of building elements—remain underexplored. Understanding the material output from renovation projects across different building types and their potential for reuse and recycling is crucial.
This thesis introduces a novel approach to calculating renovation and transformation waste, drawing on existing literature related to skip use for material intensity (MI) calculations for demolition and waste quantification. Renovations are defined as improving a building to enhance the physical conditions and functional performance. Transformations are similar to renovations but include a change of use of the building. Data on renovation and transformation projects were acquired to calculate the amount of waste generated as well as the renovation and transformation material intensities (r,tMIs) of different building types and for different construction years. The r,tMIs were calculated by dividing the mass of each material per project by the floor area of that project. The r,tMIs were then grouped by building type and construction year. The materials examined include Undifferentiated, Gypsum, Wood, Synthetic material, Paper/cardboard, and Aggregates. The building types are classified as detached houses, row houses, apartments, educational buildings, health facilities, offices, and ‘other’, with construction years grouped into Before-1945, 1945-1970, 1970-2000, 2000 and later, and Year unknown. The 358 projects are dispersed across the Netherlands and took place between January 2021 and May 2024.
It was found that the Undifferentiated waste stream constitutes a large portion of both renovation and transformation waste. Among renovation projects, apartments represent a significant portion, while transformation projects are limited to educational buildings, offices, and ‘other’ categories. Transformation projects tend to have higher tMI values compared to renovation rMIs. Undifferentiated and Aggregates are consistently present across all building types, whereas Gypsum and Synthetic materials are less common in number and mass. Additionally, a trend of decreasing tMI values for newer buildings was observed in transformation projects, a pattern not evident in renovation projects.
These insights lay the groundwork for a deeper understanding of material flows in renovation and transformation practices, serving as a strong foundation for future research. The findings can be used by renovation companies and contractors to estimate the amount of renovation waste from future projects by multiplying the r,tMIs with the specific floor area of that project. The findings can also be used by waste treatment companies to increase the efficiency of waste collection, transport, and treatment.