Energy efficient building refurbishment

Building refurbishments are realized in social housings in Innsbruck & Bolzano as well as in three primary schools in Innsbruck. Both cities together are taking up the challenge of refurbishing more than 100,000 m² of living space.

See below for more information on the comprehensive building refurbishments.

Refurbishment measures in the demo cities

In Bolzano, 37,000 m² of social housing from the 1950s to the 1970s are retrofitted to achieve high energy performance and improve interior comfort while ensuring cost effectiveness and minimal impact on tenants. Measures include:

  • Building envelope insulation;
  • Integration of renewable energy sources for electricity, heating and domestic hot water (Solar and PV panels);
  • Additional storeys using innovative timber construction technologies.

In Innsbruck, 66,000 m² of residential and public buildings from the 1930s to the 1980s are retrofitted to improve indoor quality and energy performance, and reduce final energy demand by up to 80 %. Measures include:

  • Improved envelope (insulation of façade of earth-bearing walls as well as the top floor, replacement of windows to triple glazing);
  • Installation of a ventilation system with high efficiency heat recovery;
  • Integration of renewable energy sources on-site (PV panels on the roof, solarthermal heatpumps).

More technical information on applied refurbishment measures can be found here.


Challenges and solutions for refurbishment of social housings

All refurbishment activities outlined above are performed while tenants are living in their flats. Not only technical, but also social, legal and organisational challenges have to be faced and overcome by the housing companies. Also costs and benefits of the refurbishment measures have to be in line to provide possible solutions for replication.

As an example, social housing companies & their tenants have limited budgets. Additionally, the building structure of houses of the 1950s-1979s is unknown what makes the cost estimation complex. A possible solution is a step-by-step refurbishment, focusing on cheap as well as sustainable solutions.

As tenants live in the flats during the refurbishment activities individual solutions for each tenant are needed. This requires a lot of time for planning, communication, etc. Complete refurbishment inside the flat can be recommended only when the flat is empty (step by step refurbishment). Parallel to this, a search for innovative technical solutions that can be installed in flats without major intervention is necessary.  More information on the involvement of tenants as stakeholders is available here.

Key-messages for the successful refurbishment of social housings

Consortial partners of SINFONIA identified the following key messages for the successful refurbishment of social housings based on the experiences made in Innsbruck and Bolzano:

Key-messages from Innsbruck

  • Change the image of refurbishments from negative to positive.
  • Consider tenants as your partners.
  • Refurbishments are more complicated and more expensive than the construction of a new building when considering the the whole life-cycle costs.
  • Step by step refurbishment is recommended when tenants stay in flats during refurbishment.
  • Knowledge transfer and collaboration amongst partners are essential for the success of a project.
  • Build living structures in the cities that last longer than the project duration.

Key-messages from Bolzano

  • Start the discussion and exchange with tenants at the very beginning of a project. The set-up of a participation approach is crucial.
  • Do not start a refurbishment project before having a very clear view on the actual situation and a vision of the outcomes.
  • Interventions of such a high level should be carried out in empty buildings when tenants don`t live inside.
  • No acceptable payback: Start this type of refurbishment only if your main goals are others than economic ones (e. g. social, technical, well being of tenants). You can not expect a financial profit out of these refurbishment projects.

Comparison of experiences in the two demo cities

Both demo cities faced similar challenges regarding building refurbishments. Partners underestimated the challenges they had to face, especially when it comes to the work with tenants. The high level of innovation within the SINFONIA buildings is one of the biggest challenges. SINFONIA is a research and demonstration project and the realization of activities is time consuming. The unknown building structure of old houses (1940-1970s) required comprehensive replanning and caused unexpected delays in both cities.
Representatives of both cities see two major points:

  1. The importance of interaction with tenants should not be underestimated since a positive interaction is crucial for the success of refurbishments (focus on levels of participation from the very beginning!)
  2. Generally, comprehensive refurbishment should be avoided while tenants are living in their flats. If tenants stay in their apartments during refurbishments a step-by-step refurbishment is recommended.


Challenges and solutions for monitoring of the refurbishment performance

Once the refurbishments are completed in both demo cities, monitoring equipment is installed and data from apartments and school classes is collected and transferred to a secure data server for 12 months. Temperature, humidity, CO2, heat (domestic hot water and space heating) and electricity demand are monitored by sensors inside the flats as well as on building level. The data collected is analysed regarding comfort and energy issues. Specific monitoring of field data is proposed to validate that technical and economic scaling under operational conditions is confirmed in real life by measured data.

For monitoring of building refurbishments financial, technical, legal, organizational, social and other challenges and possible solutions had to be considered by the involved partners in the two demo cities. Financial, technical and legal challenges are closely connected to each other. For a successful implementation of a 12 months monitoring concept and the cooperation between SINFONIA’s internal stakeholders it can be recommended to develop a clear concept regarding responsibilities, roles, tasks and time frame of all stakeholders involved in the monitoring process.

As examples, the calibration of monitoring devices and the question of data transfer: WIFI or cabling as well as data protection during data transfer are difficult and substantial topics for SINFONIA. Therefore data security experts need to define the required steps.

For the monitoring activities inside the apartments,  the approval of tenants is required. It is another big challenge for the building companies to convince tenants to participate in the monitoring. Housing owners have to think about how to motivate tenants, e. g. with incentives or the organisation of information events for tenant. Legally, tenants are the only owners of their monitoring data. So cooperation with tenants is indispensible.

Key-messages for the successful implementation of a monitoring concept

Based on the experiences and findings by the SINFONIA partners in Innsbruck & Bolzano the following key-messages for a successful implementation of the monitoring concept were drafted:

Key-messages from Innsbruck

  • Elaborate and use only one consistent data protection agreement for data collection, that is developed by all involved partners and their lawyers. Time consuming!
  • Use industry-standard monitoring equipment. Open source solutions might not be able to deliver data constantly and for a longer period.
  • The monitoring period should be more than one year in order to secure quality and control mechanisms. The outcomes are important for future refurbishments.
  • A critical number of flats to be monitored is necessary for statistical analysis.
  • Incentives for tenants to encourage them to take part in monitoring campaigns.

 Key-messages from Bolzano

  • It is important to start the monitoring process with a clear vision of objectives, methods and results to be achieved. Monitoring objectives have to be clear at the beginning of the project.
  • Roles and tasks of involved partners need to be clear at the beginning of the project.
  • Each partner involved has to master the framework of the monitoring process (legal issues, technical issues, planning, etc.) in order to give a positive contribution.
  • Data acquisition systems to be integrated in the existing database need to be studied in the starting phase.
  • The Municipality of Bolzano solved the problem of data protection by sending the tenants a consent form, in which the municipality asked for permission to collect sensitive data, highlighting the benefits related to monitoring activities.

Comparison of experiences in the two demo cities

In Innsbruck and Bolzano occurred similar challenges with the implementation of a monitoring concept:

  • Tenants in social housings often are not open minded towards monitoring aspects. More time than thought was needed to convince tenants of participating in the monitoring.
  • Both cities underestimated the issue of data protection. Huge administrative effort is needed to get agreements between the involved SINFONIA partners and – in a next step – tenants – very time consuming.
  • Technical aspects such as the realisation of measurements, data transfer, database structure were underestimated. Time consuming -> delays.
  • Working in a team with different institutions needs time and patience.