Stock dynamics for forecasting material flows—Case study for housing in The Netherlands
This article discusses the role of lifestyle in physical material accounting and introduces a new method for simultaneously determining national or regional resource demand and waste generation through estimations of the population and its lifestyle, which is manifested in the stocks of service providing goods, their composition and lifetimes. Improving our comprehension of the stocks in use is essential for environmental policy making because (1) they are becoming the most important resource providers, (2) they are important drivers for resource and energy consumption as well as waste and emission generation, and (3) their magnitudes and dynamics are the parts of the material cycles that is usually least understood.
A generic dynamic material flow analysis model is presented and applied for the diffusion of concrete in the Dutch dwelling stock for the period of 1900–2100. Simulation results are illustrated for a standard scenario and a parameter variation. The results show that (1) construction and demolition flows follow a cyclical behaviour, (2) the cycles of construction and demolition flows are phase displaced in the first half of the 21st century, with decreasing construction and increasing demolition, and (3) growth of the dwelling stock is becoming increasingly more material intensive as a growing amount of material is used for replacements.
The presented stock dynamics approach can principally be applied for any anthropogenic material stock; however, it is most useful for the examination of metabolic consequences of diffusion processes of durable and fixed capital stocks.