Towards Sustainable Cities: Analysis of Material Stocks and Land Use Impacts in Different Urban Settlement Types

Urban metabolism is characterized by high material and energy inputs and a high waste generation and is considered therefore inefficient and unsustainable. High material input leads to resource depletion, high waste generation... [ view full abstract ]

Urban metabolism is characterized by high material and energy inputs and a high waste generation and is considered therefore inefficient and unsustainable. High material input leads to resource depletion, high waste generation – to increasing emissions to the environment. There is a need of reducing material and energy demand and increasing resource recovery from waste in order to achieve better degree of sustainability. This need is especially urgent for construction minerals as construction materials and demolition waste are the biggest material flows. Extraction of construction minerals, production of construction materials and transport of those, as well as demolition waste transport and disposal, cause considerable environmental and economic impact in form of natural resource depletion, ecosystem damage due to land use change and greenhouse gas emissions due to energy use. The knowledge of urban building stocks and associated resource flows is needed for the assessment of the building material recovery potential from urban mining and possibilities to reduce material intensity or replace materials with high environmental impact. Land use impacts caused both by the extraction of construction minerals and land occupation by built-up urban areas are considerable. The analysis of land use patterns and material stocks and flows in different types of urban settlements can be used in physical planning in order to reduce environmental impacts. The aim of the present study was to develop the typology of urban settlement structures and assess the influence of different settlement structures on material stocks and flows and use of land. The focus was on different types of built-up urban areas relevant for cities in Norway and their characteristics in terms of material stocks of major construction minerals and wood in buildings and land use. Methodology included GIS for spatial analysis as a part of settlement typology development and building stock assessment and material stock assessment using data from Norwegian official registry of real estate and literature data on material intensity. Areas with detached houses, chained houses, multi-dwelling houses with fewer than 3 floors and several types of apartment blocks with 3 floors and higher were compared. Area with detached houses showed lowest population density, and therefore highest land use per inhabitant if only adults were accounted for, while blocks with 3 floors showed lowest land use per adult person but not always lowest material use. The further analysis is needed that would include land use impact embodied in materials. The results will contribute to the basis for recommendations for urban physical planning to enable transition towards more sustainable urban structures.

Settlement typology, building stock, material flows, spatial analysis.