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Eco-Life Site Kortrijk

Country & City

  • Belgium
  • Kortrijk


Contact Information

Ilse Piers

Goedkope Woning

The ECO-Life demonstration site in Belgium is in Kortrijk, a city located in the Flemish province of West Flanders. The wider municipality comprises the city of Kortrijk and the seven surrounding towns with a total of 74 700 inhabitants, which makes it the seventh largest city in the Flemish region.

A large number of the housing units in Kortrijk date from before 1960. They are not adapted to changed living standards, or to higher energy standards. In striving for innovation and a higher quality of life for residents, the Council of Kortrijk decided to improve the building stock through refurbishment and new construction.

*The KPIs for the new building are compared with the baseline of a reference building.

An overall area of 24 700 m2 was included in the ECO-Life project in Kortrijk. As a result of the energy efficiency, the monitored yearly energy balance was found to be 117 kWh/m²/yr on average. This amounts to 1127 MWh of final energy saved every year.

On the supply side, the following production of renewable energy has been achieved:

  • Photovoltaicss: 210 MWh/yr
  • Heat pump: 163 MWh/yr
  • Biomass plant: 1346 MWh/yr

According to the primary energy and CO2 factors provided by the project and the SCIS database, the primary energy savings go up to 5463 MWh/yr, which is 70 % of the primary energy used in the reference situation. The intervention within ECO-Life yielded 464 tonnes/yr CO2 savings under full operation (40 % in comparison to national regulations). Additionally, 346 tonnes of CO2 have been displaced by the savings from the renewable energy system.

There was a mismatch between design values and monitored values. This was mainly due to high network heat losses in district and collective heating networks, low production efficiencies, and higher energy demand for space heating in some demonstration buildings.


The following interventions were implemented in Kortrijk as part of the ECO-Life project:

Energy efficiency in buildings

  • Retrofitting the building envelope:
    • The demonstration buildings in the Venning district replaced a neighbourhood of single-family social houses built in the 1950s. Some of the houses were demolished, while others were renovated to meet higher standards.
  • Building integrated renewable energy sources
    • Photovoltaics

Energy systems integration

  • Biomass boiler
  • District heating
    • The main heating generation system in the Venning district is a biomass boiler with a capacity of 950 kWth.

The total investment costs for the interventions in Kortrijk are EUR 4 million. This includes costs for building refurbishment, building integrated renewable energy systems and energy systems integration.

The reduction of fuel costs is calculated by comparing the heat costs of the households with the heat use (for space heating and domestic hot water) of a reference building that complies with Flemish energy standards for new buildings in 2010. With such a comparison, ECO-Life calculated that the reduction of fuel costs in the ECO-Life dwellings is significant – more than EUR 450/year for an average household.

The simple payback times found in the cost analysis show a large variation between the buildings included in the demonstration site, ranging from 10 to 73 years. When EU grants are considered, the payback drops to 9 for the lowest and 33 years for the highest.

The simple payback time for the total photovoltaic and heat pump system is 1 year with the EU grant and 12 years without the grant. The heat pump shows 1 year of payback compared to a reference system (in this case a condensing boiler).

The CONCERTO approach: 

All demonstration projects are defined in a "Whole Community Approach" which means that all project initiatives are considered as integrated components. The aim is to ensure optimal interaction and balance of the energy demand and energy supply at all times.

Site facts and figures: 
  • Estimated population involved: 1.200
  • Approx. geographical area coverage: Information will follow
  • Approx. energy saving (in %): Information will follow
  • Approx. energy from RES (in %): Information will follow

Lesson Learnt

The following information has been gathered as part of the CONCERTO Premium policy research.

Benefits of CONCERTO:

Key benefits:

The project introduced a totally new way of building in a region that had to start with sustainable and low energy building. The transformation of a former ‘ghetto’ in a CO2-neutral neighborhood got the attention of a large number of people, not only local but also national and international. It was a plea for another way of living and building. Introducing high quality sustainable building in (rental) social housing was not done on this scale in Belgium before. The social aspects were even more important than the innovative potential of the technical solutions. The local district heating system on biomass was a pioneer for other districts. The monitoring and evaluation of the project gave an opportunity to get a lot of practical experience. It was an interesting example (case study) for contractors, architects and developers. It opened interesting discussions and debates

Skill development:

The building contractor gained more experience in passive building.  It was the first passive social housing project of that scale, so knowledge about this way of building and living was be gained and disseminated in the social housing sector.

Local economic effects:

Local employment: Ca. 150 full-time equivalent (FTE) person-years were required for the planning and construction of the CONCERTO project.

Barriers encountered:

Legal barriers:

Lack of relevant by-laws/ordinances at the local level, long and difficult authorization procedures, renewable energy technologies insufficiently taken into account in spatial planning and planning rules against biomass incineration plants due to emissions and transport movement.

Solutions for the public sector:

Make everything more simple and open. Abolish all the detailed obligations and rules, based on practices in the eighties and nineties, before the climate problem was well-known. Learn to work together with the private sector to reach the ambitious goals.

Technical barriers:
vLack of training in the sector especially for installers is not a real problem today, because there are not so many projects with this quality level. It will be a problem in the context of EU 2020: too late, too little.

Design barriers:

It is another way of designing buildings, working together, sharing problems and making choices by discussing the consequences.

Wrong foresight in town planning: we need a new generation of town planners, arising from a new education in universities and high schools

Solutions: More innovative pilot projects and more practical lessons.

Economic barriers:

High construction costs: Construction cost for Venning was 15% higher than standard. For this budget we delivered a CO2-neutral green neighborhood and passive houses for social tenants (real cost ca 1300 €/m²). This cost was not so high, but in times of economic crises direct building costs seem to be more important than total life costs. Only the standard construction files for social housing (ca 1120€/m²) get a permit today (to get an interest-free loan), except pilot projects with an extra subsidized budget.

Solutions: Give the social housing companies (such as Goedkope Woning) developing innovative and high quality sustainable projects, the possibility to borrow from the bank (very low rates at the moment).Give some subsidy (also from EU) to help the social housing companies to refund this additional cost (above the normal interest-free loan). Make a simple monitoring system to control if the ambitious targets are achieved. If you do this in social housing it means considerable savings for the underprivileged people in Europe. For them energy costs have an important influence on their daily living budget

Social barriers:

Slowly growing awareness among target groups (constructors, architects, home owners, real estate companies): everybody is learning, nobody knows the best and more sustainable solutions.

Lack of practical experience. Growing awareness among the general public, but lack of information based on real experience.

Low acceptance of new projects: depends of the region (bigger cities have better structured administrations to help the target groups).

Resistance towards behavior changes:  this was the biggest problem with the ECO-Life projects in Kortrijk. Everybody (politicians, administration…) agrees the importance and necessity, nobody is able or willing to change or transform his bad habits. They aren’t even aware of their bad attitudes.

Solutions: More local innovative projects with support from EU. It is very complicated and difficult to convince the tenants to change their way of live, especially when it is clear that local responsible refuse to change their habits

Administrative barriers:

High number of authorities involved, lack of coordination between different authorities and normally in Belgium master plans are not based on studies that analyze the opportunities of using local energy sources and installations. There are some exceptions (projects).

Solutions: Belgium has 11 million inhabitants, Flanders has 6.5  million inhabitants, a small city on the world map. Kortrijk is a tiny village in this context. Why make all these internal administrative barriers, next to the European, Belgian, Flemish, local …? Let’s make ONE European ordinance for everywhere in the EU.


The CONCERTO project at Kortrijk covers the new construction areas “Pottenbakershoek” (Picture 1) and “Venning” (Picture 2). The goal is to reach a zero-carbon-emission energy balance (electricity for household excluded) for the two area together. At Venning there are built four multi-family houses (82 dwellings in total) and 64 single-family houses; 50 single-family houses will be refurbished. At Pottenbakkershoek one multi-family building with 23 dwellings is built. All buildings are designed with the passive house concept as a guideline and will be established with common or individual heat recovery ventilation or demand-controlled exhaust air ventilation.

All buildings at the Venning area will be supplied by a new low temperature district heating network (Picture 3+4), which is supplied by a 1 MW wood chip boiler. A small 10 kW biofuel cogeneration unit produces the auxiliary electricity for the system (pumps, control and monitoring equipment). Its small amount of heat is additionally fed into the district heating network. the hot water buffer tanks are 15 m3.

The Pottenbakkershoek building is supplied by a natural gas air to air heat pump for heating and domestic hot water. The yearly needed energy of gas in balance will be compensated through the energy produced by the photovoltaic systems on the roof (40 kWpeak, monocristalline). At the Venning area 150 kWpeak of photovoltaics (polycrystalline) will be installed in total (Picture 5) for compensation of the electricity use for HVAC (ventilation, pumps…), lifts and lighting of common areas.

In the Venning area, a mobility study was made. The masterplan provides various measures to encourage the people to use the bicycle (or walk) instead of the car. Solutions for a better connection (for pedestrians and cyclists) with the city centre are suggested.

In all buildings and systems a detailed technical monitoring will be performed. Time resolution is going down from daily to even 5-minute intervals. See “More detailed” for additional information on the monitoring activities at Kortrijk.



A detailed monitoring concept has been developed. In order to achieve the best possible performance of the neighbourhood and to achieve the maximum benefits with the ECO-Life project, it is important to continue the efforts during the operational phase by addressing the following aspects:

  • Manage the operation of the buildings and building services as smart as possible
  • Learn people how to use the buildings/services in the best possible way
  • Make people aware about their proper energy use and energy saving potential
  • Activate people to improve their proper energy efficiency
  • Make people aware of the importance of saving energy and their impact on the climate
  • Demonstrate the feasibility of energy efficiency and renewable energy supply
  • Assess and document the performance of the zero-carbon neighbourhood

In this context, the intelligent metering system will serve four purposes: control and management of the various demonstration buildings and building services, feedback to the end-users (inhabitants), demonstration of renewable energy and energy efficiency to various groups of people (internal and external to the ECO-Life project) and performance assessment of the demonstration dwellings, buildings, energy systems and the neighbourhood.

The central components of the intelligent metering and building management system will be physically located in the technical building of the Venning neighbourhood. The core system enables a number of operations such as configuration, commissioning, archiving, monitoring, commanding, diagnosis, processing, presentation (...) of data. Data are sent to data servers, where they can be stored for the long-term by means of a standard database platform. Both network integration engines and data servers can be accessed from the operator PC in the technical building and from remote via standard web browsers.

Considering the monitoring of heat and electricity production, all renewable and non-renewable energy inputs are metered, as well as the net production of heat and electricity and the heat losses at the storage and distribution in both community areas Venning and Pottenbakkershoek. Regarding the monitoring of the energy use in the dwellings and buildings, the heat use, electricity use, water consumption and indoor climate parameters are measured (Picture 6). Additionally, some parameters of the building services (e.g. ventilation devices) are monitored to assess their performance and energy use.

CONCERTO technologies

Renewable Energy Source: 
  • Liquid Biofuel
  • Solid biomass
  • Sun
Low Carbon Technologies: 
  • Biomass boiler
  • CHP with Biomass Fuel
  • District Heating and Cooling
  • Heat pump
  • ICT
  • Photovoltaics