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Sector-wide Circularity Assessment
for the construction sector
Mikkeli

Introduction

The EU Horizon 2020 funded CityLoops project focuses on closing the material loops of two central sectors of any city in terms of material flows, societal needs and employment, namely the construction and biomass sectors. Due to their sizes, they represent a considerable opportunity for cities to transform their metabolism and economy towards a more circular state.

Within this project, seven European cities, amongst those also the City of Mikkeli are planning to implement demonstration actions to kickstart their circularity journey. To better understand what the current circularity status quo is, as well as the impact of these actions, and the efforts needed to transform their sector, a Sector-Wide Circularity Assessment method was developed. This method combines a circular city and circular sector definition, a material flow and stock accounting method, as well as circularity indicators. The sector itself was defined in terms of a number of representative materials that make up a large share of the sector and associated economic activities. The construction sector is made up of 11 materials, depicted as icons here, which were studied along the entirety of their supply chains. Altogether, these elements help to set a solid knowledge and analytical foundation to develop future circularity roadmaps and action plans.

Aluminium
Bitumen / asphalt
Bricks
Concrete
Glass
Gypsum
Insulation
Iron (steel)
Sand and gravel
Soil
Timber

The assessment was carried out by the cities themselves after receiving extensive training in the form of courses on data collection (construction and biomass) and data processing. Numerous additional insights can be found in the individual Data Hubs of each city.

This current Sector-Wide Circularity Assessment report provides contextual information on the city and the economic sector under study. It then illustrates how circular these sectors are through circularity indicators and a Sankey diagram. Finally, it analyses and interprets the results, presents the limitations from the data used and offers recommendations about how to make this sector more circular.

(* The italic texts in this report were written by Metabolism of Cities' Aristide Athanassiadis and Carolin Bellstedt. They provide relevant general information and serve as connecting elements of the single report parts.)

Urban context

To contextualise the results of the sector-wide circularity assessment, this section provides population and land use information data of the city. In addition, population and area of the city under study, as well as its corresponding NUTS3, NUTS2 and country were included. Data for these scales were added to better understand how relevant and important the approximations are when downscaling data from these scales to a city level.

Mikkeli
53,134
3,229 km2
Etelä-Savo
144,615
19,130 km2
Pohjois- ja Itä-Suomi
1,278,237
236,450 km2
Finland
5,525,292
390,908 km2

Population of Mikkeli

In year 2019, there was 53 130 inhabitants in the city of Mikkeli, of which 13.9% were aged 0-14, 60.2% were aged 15-64 and 25.7% were over 65 years old. The population of the city of Mikkeli has been slightly declining in the 21st century, but since 2016 the population change has clearly accelerated and the city lost almost 1 400 people between 2016 and 2019. The negative demographic development of the city of Mikkeli is largely the result of two components: natural demographic change has accelerated slightly, but especially outward migration (particularly emigration of young adults) has increased considerable in 2016-2019. In 2019, Statistics Finland published a new population forecast for the city of Mikkeli. The city’s population is predicted to decline by 11 % by 2040. (Kumpusalo 2020, Mikkeli Development Miksei Ltd)

In 2018, Mikkeli was the 18th largest city in Finland by population. (City of Mikkeli website)

Land use

  • Agricultural areas
  • Artificial surfaces
  • Forests
  • Roads
  • Water bodies
  • Wetlands

Data source

There are various living environments in Mikkeli. These include a growing downtown area, developing agglomerations and the quiet of the rural area. Living in Mikkeli is divided in two main area types: city/agglomerations and dispersed habitat/rural area. There are numerous summer cottages at the lake- shores of the rural areas. There are around 700 lakes and ponds in Mikkeli and water covers 424.7 km2 (13 %) of the city. (Riihelä et al. 2015)

Forests and other natural areas account for 89.6% and agriculture for 5.8% of Mikkeli's land area. (Use of land in Mikkeli for extraction and harvesting, agriculture and forests 2018)

Economic context of construction sector

This section puts into perspective the economic context of the sector under study. It describes how many people are employed in this sector, as well as who the main actors involved (from all lifecycle stages for the sector’s materials) are.

GVA (monetary value, in €) Employees
Mikkeli 141,000,000 1,307
Etelä-Savo 272,000,000 3,515
Pohjois- ja Itä-Suomi 3,227,000,000 9B
Finland 14,978,000,000 167,861

The construction sector in Mikkeli

The construction sector employs 11,2% of employees in Mikkeli. The corresponding percentage for the whole country is (7%). The most significant employment sectors in Mikkeli are industry (22,6%) and wholesale and retail trade (17,6%). Construction accounts for about 10% of Mikkeli's net sales. Based on turnover, the most significant industries in Mikkeli are wholesale and retail trade (28%) and industry (26%). (Data of Statistics Finland on industries and employees in Mikkeli) Data is from year 2018 (GVA and employees data from reference year 2019 was not available).

In Mikkeli, the largest construction projects are often managed by national companies and employees can also come from outside the area. According to the 2019 statistics, the number of new buildings in Mikkeli was 171 and the total floor area was 19,994 m2. About half of the floor area (48 %) was residential buildings. 76% of the house types were detached houses, 21% terraced houses and 2% apartment buildings.

![](https://cityloops.metabolismofcities.org/media/records/mikkeli-building-topology-subset-with-values.large.png) [Data source](https://cityloops.metabolismofcities.org/library/981408/)

The actors of the construction sector

The actors of construction sector were listed by using data of Statistics Finland, where the total number of actors, employees as well as economical information are given by NACE-codes (EU classification of economic activities): (Industries and employees in Mikkeli 2013-2018).

Also A list of actors in Mikkeli by Nace codes was available. However, the list is not totally coverable and some important actors are missing from this listing. Information was collected from companies webpages as well.

Extraction and harvesting

Forests and forest-based industries are very important source of economic well-being in Southern Savonia. The incomes from the harvesting of province´s forests are the highest in the country. The forests are mostly owned by private forest owners. (Metsäkeskus 2020)

![](https://cityloops.metabolismofcities.org/media/records/mikkeli-harvested-wood-area-graph.large.png) [Data source](https://cityloops.metabolismofcities.org/library/991532/)

Mikkeli has a total of 52 soil extraction permits for gravel and sand, 35 for stone materials and 8 for other materials. Materials are used for construction and for manufacturing of concrete. There are no statistics on actors available, but e.g. Metsähallitus, concrete manufacturers and earthwork companies own extraction sites. (Data on soil extraction pemits and amount of extracted rock and gravel in Mikkeli)

![](https://cityloops.metabolismofcities.org/media/records/mikkeli-soil-extraction-permits-rock-reserves-map.large.png) [Data source](https://cityloops.metabolismofcities.org/library/983158/) ![](https://cityloops.metabolismofcities.org/media/records/mikkeli-extracted-rock-gravel-area-chart.large.png) [Data source](https://cityloops.metabolismofcities.org/library/981359/)

Manufacturing

Mikkeli has several actors manufacturing timber and concrete products for construction sector throughout Finland and for export.

Actors in timber manufacturing:

According to Statistics Finland, there were a total of 12 actors in the sawmilling and planing of wood, 1 actor in manufacture of veneer sheets and wood-based panels, 1 actor in manufacture of assembled parquet floors and 6 actors in Manufacture of other builders' carpentry and joinery in 2018. (Industries and employees in Mikkeli 2013-2018).

There were also 6 actors in Manufacture of other products of wood; manufacture of articles of cork, straw and plaiting materials, 4 actors in Manufacture of kitchen furniture and 3 actors in Manufacture of other furniture. However, the role of these actors to the total material flows is assumed to be low. The most important actors in timber manufacturing are:

  • UPM Pellos' plywood mill is Europe's largest plywood mill. It produces approximately 480,000 cubic meters of plywood per year from approximately 1.1 million cubic meters of Southern Savonia spruce logs for the Finnish and European markets. The factories employ about 600 people and are the largest industrial employer in Southern Savonia (Kumpusalo 2019, Mikkeli Development Miksei Ltd)
  • Versowood Otava Ltd: The production capacity of spruce sawing is about 275,000 m³ per year. 90% of production is exported.
  • Misawa Homes of Finland Ltd is a sawmill which export spruce lumber to Japan.
  • SWM-Wood Ltd manufactures heat-treated wood for the needs of the construction and carpentry industries and retailers. Company is the 2nd largest manufacturer of Thermowood® in Europe
  • Oplax Ltd: manufacturing of pallets
  • Parla Floor, Timberwise: manufacturing of parquet floors

The production volumes of these companies were used to calculate material flows in manufacturing of timber products in Mikkeli.

![](https://cityloops.metabolismofcities.org/media/records/mikkeli-timber-manufacture-bar-graph.large.png) [Data source](https://cityloops.metabolismofcities.org/library/991181/)

Actors in concrete manufacturing:

![](https://cityloops.metabolismofcities.org/media/records/mikkeli-concrete-manufacture-bar-graph.large.png) [Data source](https://cityloops.metabolismofcities.org/library/990193/)

There are also companies of metal industry in Mikkeli (17 actors in 2018) who manufacture metal products (metal structures and their parts, metal doors and windows, and perform metal processing and coating). (Industries and employees in Mikkeli 2013-2018)

Retail and wholesale

In 2018, Mikkeli had 45 actors related to the retail and wholesale of construction materials (NACE codes 46.73 Wholesale of wood, construction materials and sanitary equipment and 47.52 Retail sale of hardware, paints and glass in specialised stores). Some biggest actors are e.g. K-Rauta, Carlson and Stark. (Industries and employees in Mikkeli 2013-2018)

Use

There were 425 actors in the construction sector in Mikkeli in 2018 (Industries and employees in Mikkeli 2013-2018). Most of these are small companies. The largest construction projects are often managed by national companies such as YIT, Skanska and Destia.

Waste collection and treatment

The most significant operator responsible for waste collection and treatment in Mikkeli is the city-owned waste management company Metsäsairila Ltd. All construction and demolition waste generated from the City of Mikkeli's own sites is delivered to Metsäsairila. Private operators can deliver waste elsewhere, also outside Mikkeli, depending on the contractor. Otavan Metalli Ltd and Mikkelin Romu Ltd receive scrap metal in Mikkeli. Mikkelin Romu Ltd receive also construction, wood and demolition waste. According to environmental permits of companies, concrete and timber manufacturers treat (e.g. crush) waste fractions generated from their own production and deliver for recycling or incineration. Suutarinen Ltd can also crush concrete waste from the construction and demolition sites in their concrete plants in Tikkala and Suomenniemi. In addition, at least Mikkelin Autokuljetus Ltd has an environmental permit for crushing and receiving concrete waste. Mikkelin Toimintakeskus assoc. focuses on the re-use fixing and upcycling of goods and materials. They sells small quantities of materials from e.g. renovation and demolition sites to reuse.

![](https://cityloops.metabolismofcities.org/media/records/mikkeli-cdw-waste-flows-area-chart.large.png) [Data source](https://cityloops.metabolismofcities.org/library/991950/)

Indicators

To monitor the progress of this economic sector towards circularity, a number of indicators were proposed and measured. Altogether, these indicators depict several facets of circularity of the sector. As such, they need to be considered in combination rather than in isolation when assessing circularity. In addition, these indicators can be compared to other cities or spatial scales (such as the country level). However, this has to be done with great care and use of the contextual elements in the previous sections of the report. Finally, the value measured from these indicators can be traced over time to track the sector’s progress towards circularity.

Indicator number Indicator Value Unit
34 Domestic material consumption (DMC) 561,715.39 Tonnes/year
39 Circular Material Use Rate 2.58 %
48 EU self-sufficiency for raw materials 4.91 %
55 EOL-RR (End of Life Recycling Rate) 25.26 %
57 Amount of sector specific waste that is produced 35,598.00 Tonnes/year
58 End of Life Processing Rate 97.27 %
59 Incineration rate 0.00 %
61 Landfilling rate 7.59 %

Due to deficiencies in data quality, not all indicators could be calculated with complete reliability.

Domestic material consumption

DMC is the total amount of materials directly used by an economy and is defined as the annual quantity of raw materials extracted from the domestic territory, plus all physical imports minus all physical exports. Formula for domestic material consumption is: DMC = Domestic extraction used (DEI) + Imports (IMP) – Exports (EXP).

In the case of Mikkeli, DEI was calculated using reliable local or regional data on extraction of sand & gravel and soil (peat) as well as harvesting of wood. This value was allocated for manufacturing (50 %), retail (20 %), use (10 %) and waste collection (10 %). Assumed allocation values defined by Metabolism of Cities (MOC) were used.

Imports (IMP) were calculated using Finnish Customs data from Finland and downscaling it to Mikkeli by using employees of construction sector. This value was allocated for manufacturing (40 %), retail (40 %), use (0 %) and waste collection (0 %). Assumed allocation values defined by Metabolism of Cities (MOC) were used.

Amount of exports (EXP) are based on rough estimations and downscaling of national Finnish Customs data (see Chapter Data Quality).

The resulted DMC in Mikkeli is 561,715.39 tonnes per year and 10.6 tonnes per capita which is slightly better than the reference value 13.4 tonnes per capita for EU-28 in 2019 (Eurostat). Generally a decrease in the indicator value is beneficial to the environment and to the Green Economy Source.

Circular material use rate

Formula for Circular material use rate is: (domestic recovery – imported waste for recycling – exported waste for recycling) / ((domestic material consumption + (domestic recovery – imported waste for recycling – exported waste for recycling )).

Domestic recovery is amount of collected waste that is recycled. In case of Mikkeli, the reliable data was obtained from the most important actor Metsäsairila Ltd but data does not cover all waste flows from private sector (see chapter Data Quality).

Imported waste for recycling is based on assumed allocation values defined by the Metabolism of Cities. Assumption is that 20 % of all imports are allocated to recycling. In case of Mikkeli, imports (IMP) were calculated using Finnish Customs data from Finland and downscaling it to Mikkeli by using employees of construction sector. From this value, 20 % was allocated to recycling

Exported waste for recycling is based on actual amount of metal waste that is collected by Metsäsairila and exported outside of Mikkeli for recycling. Data does not cover local private actors, who receive metal waste or other CDW and export it for recycling.

Calculation of Domestic Material Consumption has been described above. In case on Mikkeli there are many uncertainties due to downscaling, rough estimations and assumed allocation values.

The resulted Circular Material Use Rate CMU for Mikkeli is 2,58 % which is low compared to 12.4% for EU-28 or 6,3 % for Finland in 2019 (Eurostat). Low value means that less secondary materials have substituted for primary raw materials in Mikkeli than in EU or Finland. However, the data collection and quality should be developed to get more reliable value.

EU self-sufficiency for raw materials

Formula for EU self-sufficiency for raw materials is: Import Reliance (IR) = Net import / Apparent consumption = (1- (Import - Export)) / (Domestic production + Import - Export).

Import value is based on Finnish Customs data from Finland. Data has been downscaled to Mikkeli by using employees of construction sector.

Export value is based on rough estimations and downscaling the Finnish Customs data (see Chapter Data Quality).

Domestic production is the manufacturing of construction products in Mikkeli. Value is based on reliable local data on manufacturing of concrete and timber products and downscaled PRODCOM data of Statistics Finland for manufacturing of aluminum and iron (see Chapter Data Quality).

The resulted value for EU self-sufficiency for raw materials in Mikkeli is 4,91 %. The reliability of the value is weakened by the uncertainties of the import and export data. EU statistics (Eurostat) are given for individual materials (mostly metals) and e.g. timber and concrete are not listed in the statistics. EU self-sufficiency for e.g. aluminum for EU-28 was 9,8 % and for iron 28,2 % in 2018.

EOL Recycling Rate

For each material fraction, the End-of-Life recycling rate is defined as the End-of-Life mass recycled divided by the available mass of End-of-Life materials. It is the product of the Processing Rate and the Collection Rate (EoL RR = EoL PR x EoL CR). Formula is: EOL RR = EOL Mass recycled / EOL Mass collected x 100.

In case on Mikkeli EOL mass recycled include CDW collected by Metsäsairila Ltd which is recycled at Metsäsairila (e.g. concrete waste used in road, field and landfill structures) or exported to recycling (metals). Data does not cover CDW collection of private actors.

EOL mass collected is calculated by summing the following amounts:

  • share of materials from "use" lifecycle stage that goes to waste collection (allocation value of Metabolism of Cities, 20 %). Data on use of construction materials is based on statistics of e.g. new buildings and roads in Mikkeli and there are many uncertainties in unit conversions of the data (see Chapter Data Quality).
  • share of stock materials that goes to waste collection. In case of Mikkeli this is calculated by using amount of CDW collected by Metsäsairila and assumed allocation value defined by Metabolism of Cities, 99 %.
  • share of imports that goes to waste collection. However, allocation value has not been given and the value is 0.

The resulted EOL Recycling Rate for Mikkeli is 25,97 %. There are many uncertainties and assumptions associated with calculating the value. If only the realised amount of CDW collected by Metsäsairila and CDW fractions recycled by Metsäsairila or exported to recycling are taken into account, the recycling rate is 80%. Through the EU Waste Directive, Finland was committed to utilizing at least 70% of the construction and demolition waste generated in the country as a material by year 2020. The aim of the CityLoops project is that the recycling rate of construction waste is close to 95 % in Mikkeli.

Amount of sector-specific waste that is produced

The amount of sector-specific waste that is produced was 35598 t. The amount is based on only data of Metsäsairila Ltd. Asbestos (376 t) and insulation wools (596 t) were removed from total CDW amount received by Metsäsairila Ltd. because they are not in scope of materials selected to SCA. (Materials included to SCA have been listed in the introduction part of this report. Insulation material included in SCA is only plastic based insulation.) Private sector can deliver CDW also to other local waste collectors or export it outside from Mikkeli. Mikkeli Development Miksei Ltd have studied waste management of CDW in Mikkeli (see report here). According to the study, it is estimated that about 70 % of all concrete and brick waste from big demolition projects (area of buildings >250 m2) are delivered to Metsäsairila. Consequently, the amount of sector-specific waste that is produced is bigger than amount calculated here.

End-of-Life Processing Rate

The End-of-Life Processing Rate measures the efficiency of the end-of-life processing process. The formula is: End-of-Life Processing Rate = End-of-Life mass recycled / End-of-Life mass collected for recycling x 100. The indicator shows only the local situation of the municipality and exported waste flows are not included in the calculation. This aspect helps with local circularity planning. Recycling waste elsewhere means that these materials aren't necessary available locally anymore.

In case on Mikkeli, EOL mass recycled include CDW collected by Metsäsairila Ltd which is recycled at Metsäsairila (e.g. concrete waste used in road, field and landfill structures).

EOL mass collected for recycling include CDW collected and recycled by Metsäsairila Ltd (e.g. concrete waste used in road and field structures) as well as metal waste which is collected by Metsäsairila but exported outside of Mikkeli for recycling.

The resulted EOL Processing rate is 97,27 %, which means that almost all of the waste collected by Metsäsairila Ltd for recycling, are also recycled at Metsäsairila area and only small part (metals) are exported elsewhere for recycling. In case of Mikkeli, most of CDW is utilised in Metsäsairila area in field, road and landfill structures. Data does not cover CDW collection of private actors.

Incineration rate

Incineration rate is mass percentage of waste which is incinerated. The formula used in SCA is: Incineration Rate = Incinerated waste / (Total waste + imported waste - exported waste) x 100. The indicator shows the local incineration only.

In the case of Mikkeli, the amount of local incineration is 0 because there is not waste incinerator in Mikkeli. Consequently, the incineration rate is also 0 %. The value is based on data from Metsäsairila Ltd. However, timber waste collected by Metsäsairila Ltd, is exported outside of Mikkeli for incineration and energy recovery. The proportion of timber waste exported for incineration from all collected CDW in Metsäsairila Ltd. is 12.9 %. Also energy waste fraction consisting e.g. paper/cardboard- and plastic based wastes (also plastic based insulation) are exported from Metsäsairila to incineration. However, the proportion of energy waste fraction coming from construction sector is not possible to distinguish from other energy waste from statistics.

Landfilling rate

Landfilling rate is mass percentage of waste which is landfilled. The formula used in SCA is: Landfilling rate = Landfilled waste / (Total waste + imported waste - exported waste).

In case of Mikkeli, landfilled waste consists of reject which cannot be sorted, materials mixed with soil and gypsum. Also asbestos waste and insulation wool are landfilled in Metsäsairila, but these fractions were not under the scope of sector-wide circularity assessment (Materials included to SCA have been listed in the introduction part of this report).

Total waste include the CDW collected by Metsäsairila Ltd. Data does not cover CDW collected by local private actors or CDW transported outside of Mikkeli.

Imported waste is 0. Metsäsairila or other actors can receive waste also from nearby areas, but the data is not available.

Exported waste include metal and timber waste collected by Metsäsairila Ltd. Metal waste is exported for recycling and timber waste for incineration.

Landfilling rate of CDW received by Metsäsairila Ltd is 7.59 %.

Visualisations

Measuring circularity is a data heavy exercise. Numerous datasets were collected and visualised throughout the sector-wide circularity assessment process. To synthesise these findings, a Sankey diagram illustrates how material flows from the studied economic sector are circulating from one lifecycle stage to another. The height of each line is proportional to the weight of the flow. This diagram therefore helps to quickly have an overview of all the materials flows that compose the sector and their respective shares. The flows that are coloured in light blue in the Sankey diagram, are return flows. This means that they flow in the opposite direction of the lifecycle stages and are subjected to reuse, redistribution, or remanufacturing. Their size relative to the others is a good indication for the materials' circularity.