By Henna Teerihalme
The Helsinki region's circular economy indicators for construction illustrate how to measure circularity for the region's buildings in terms of demolition, new construction and the existing building stock.
The real estate and construction industry plays a leading role in promoting circular economy solutions and curbing climate change. Vast quantities of materials are used in construction and, correspondingly, in the demolition phase, emissions are released in significant quantities. In turn, increasing reuse and recycling of buildings and their materials reduces the consumption of virgin materials. In order to support the transition to a circular construction sector, there must be measurable and targeted indicators in order to monitor progress made to achieving set goals. The indicators support, for example, city planners and decision-makers in promoting circular economy solutions in construction. Circular economy indicators in construction can be divided into three main groups: 1. Circular economy indicators for demolition These illustrate the degree of circularity in demolition operations. How much of the dismantled building parts will be reused in the following sites? And how much of the building materials can be recycled? 2. Circular economy indicators for existing building stock These illustrate, for example, how well the current building stock is used (utilisation rate) or how well the buildings are maintained and repaired so that they serve their users as long as possible. And how well the uses of buildings can be changed, if the original use no longer serves the needs of the area. 3. Circular economy indicators for new construction These can illustrate, for example, how different circular construction criteria have been taken into account in construction sites. Has longevity, versatility and adaptability been taken into account in the design of the buildings? Are the buildings designed for easy maintenance and repair? In new construction, circular construction indicators can also measure the use of reused building parts or recycled building materials or how well the building parts and materials can be used in the future. As part of the CIRCuIT project, feasible regional or city-specific indicators of the circular economy in construction were investigated and pilot solutions were produced from them. The produced indicators are:
Circular economy indicators for deconstructing buildings:
1. Amount of construction and demolition waste per inhabitant Currently, the data capture method only measures and produces statistics for the whole of Finland. At a city level, the indicator can be calculated, for example, in proportion to the population. However, this does not enable, for example, the monitoring of measures at the city level. HSY produces statistics and calculations for the Helsinki region.
2. Recycling rate of construction and demolition waste
Currently, the data capture method only measures and produces statistics the whole of Finland. The indicator can be calculated at a city level in proportion to the population. However, this does not enable, monitoring of measures at a city level, for example. HSY produces calculated statistics in the capital region.
Circular economy indicators for the existing building stock:
1. Repair and alteration work in relation to new construction
The indicator can be applied in at least some Finnish cities. It states the amount of renovation and modification in relation to the amount of new construction, i.e. it describes the investment in maintaining the existing building stock / new construction.
2. Annual discharge rate
That is, the amount of demolition in relation to the current amount of building stock. The indicator can be applied in at least some Finnish cities.
3. Average age of demolished buildings
This describes the average life cycle of buildings. The indicator can be applied in at least some Finnish cities.
Other potential circular economy indicators:
Circular economy indicators that require development
Construction and reuse of demolition waste (in relation to the total amount) Development is required to measure and capture data for this, as it's not currently possible to calculate at the city level. It must be decided whether, for example, value would be a better unit of measure than weight.
The share of recycled building materials and reused building parts in the materials used in new construction Development is required to measure and capture data for this, as it's not currently possible to calculate at the city level. Currently, no information is collected on what proportion of building materials are recycled or reused.
Reuse potential of building components of the current building stock and recycling potential of materials Development is required to measure and capture data for this, as it's not currently possible to calculate at the city level. The indicator can be produced at a rough level by calculating the construction parts / materials committed to the current building stock and making assumptions about their reusability / recyclability.
Average age of the building stock The indicator can be produced in at least some Finnish cities, also by building category.
Occupancy rate of facilities in the city Development is required to measure and capture data for this, as it's not currently possible to calculate at the city level. Possibly countable in the city organisation's own properties.
Convertibility of the building stock / conversion possibilities This requires the development of information production and a set of criteria for modifiability. Currently not produced at city level.
Obsolescence of the building stock This would require the development of data collection and a method for determining the level of obsolescence. Currently, no statistical information is produced to quantify levels of building stock obsolescence.
Flexibility in new construction This would require the development of a method suitable for measuring the flexibility of buildings. At the moment, no (statistical) information is produced on the properties that affect the flexibility of buildings.
New buildings that take into account circular economy principles / circular economy criteria This would require the development of data production, currently not possible to determine at the city level. Currently, no information is collected on the implementation of the circular economy in construction.
The average conversion capacity of new sites in the city It requires the development of information production and the determination of the desired level of modification. It is currently not possible to implement at the city level.
The recycling potential of building materials and building parts reuse in new buildings This would require the creation of a reuse potential scoring system for building materials. Currently, the required information is not available.
Henna Teerihalme is Project Manager for CIRCuIT at HSY in the Helsinki region. This article was first published in Finnish on HSY's website here.
The circular economy indicators for construction were developed as part of the Horizon 2020-funded EU project Circular Construction in Regenerative Cities (CIRCuIT). The results of the capital region and other metropolitan areas that participated in the project can be found on the Circularity Dashboard pages.