The Urban Mining Index pursues the aim of keeping building materials in as closed cycles as possible.

The resulting urban mine counteracts the increasing scarcity of resources and environmental pollution.

This is the Urban Mining Index

The construction industry is the sector with the highest resource consumption and waste generation, both nationally and internationally. Due to the increasing scarcity of resources and environmental pollution, it is necessary to manage building materials in cycles that are as closed as possible and compatible (consistent) with the environment. The Urban Mining Design pursues this approach by designing and managing the anthropogenic raw material store as an “urban mine”. For this, the cycle consistency of buildings must be understood as a design parameter. In order to be able to take the design principles of urban-mining-friendly construction into account, planners need new, quantitative evaluation standards.

Nature is a circular system.

Nature has taught us to think in cycles.
With the extraction of material resources, humans intervene massively in natural cycles. Materials that are removed from the natural cycle must be processed and used in such a way that they can either be returned to the natural cycle, or they must be permanently recirculated in technical cycles.

Systematics

The Urban Mining Index is a system for the quantitative assessment of the recycling potential of building structures in new construction planning. Over the entire life cycle of the structure, all incoming materials and all resulting valuable and waste materials are calculated and evaluated according to the quality levels of their subsequent use.

In the post-use phase, special attention is paid to the disassembly capability. The economic viability of the selective deconstruction measured on the materials’ residual value and the effort to re-extract them in mono-fractions at the end of the useful life, determines the probability for a material to reach a high-grade or low-grade end-of-life-scenario.

Quality levels

The circular materials’ share in the entirety of materials used in a building’s life cycle constitute the overall result: The Urban Mining Indicator. ​To calculate this, the circularity rates of construction materials are determined by specific values: the portion of secondary or renewable resources and the future recycling potential. Different quality levels of the circular material utilisation pre-use and post-use are differentiated and individually assessed: 

The closed-loop potential is the percentage of materials and building materials of a construction that can be kept in closed cycles without loss of quality, taking into account defined criteria (reuse and recycling).

The loop potential of a construction includes not only the percentage of closed-loop materials but also the percentage of materials and building materials whose quality diminishes in open cycles under consideration of defined criteria (further use and downcycling). The loop potential thus maps open loops in addition to the closed loops.

Assessment levels

Building

Assessment
Urban Mining indicator

Building Component

e.g. exterior wall,
Mullion-transom facade

Assessment
Circularity potential, mass-weighted, cumulative

Construction element

e.g. cladding,
supporting structure, windows

Assessment
Circularity Potential,
mass-weighted

Component layer

e.g. facing shell,
insulation, reinforced concrete,
Window frame, insulating glass

Assessment
dismantling effort, Separability

Material

e.g. clinker, wood fibre insulation,
steel, concrete,
profiled wood, glass, plastic

Assessment
subsequent use/
subsequent usability,
Value

Raw material

e.g. wood, oil,
steel scrap, aggregate,
limestone, quartz sand,
broken glass

Assessment
primary/secondary,
not renewable/
renewable

The circularity potential of a building is assessed at different levels. The interactive graphic shows the assessment basis within the respective levels.