Sonderborg Building Retrofitting Complete

20 Mar 2019

A description of the completed energy retrofitting measures in the involved housing buildings and of the decision-making process for the energy retrofitting measures, a description of the design phase, the tendering phase and a description of the implementation phase.

The building retrofitting demonstration area in Sonderborg, DK contains different types of residential buildings from 1950-1980's. All demonstration buildings are owned by social housing associations in Sonderborg.

In Sonderborg 34% of the inhabitants are living in social housing association buildings. In this project, activities of different housing associations in the same area are demonstrated. This is a replicable situation in a large part of Europe 

The departments have implemented different energy retrofitting measures, including:

  • Insulation of façades, airtight constructions, new low energy windows and doors,
  • new ventilation systems with heat recovery replacing traditional exhaust air ventilation systems,
  • new outdoor LED street lighting in the surrounding ground areas and in stairwells,
  • automatic heating control systems in district heating supply of the buildings,
  • improvement of indoor climate,
  • installation of in total 6.000 m² of building integrated solar photovoltaic plants for electricity supply with focus on good architectural integration of the solar panels in roofs.

The average energy savings in the seven departments is expected to be 30%.

The purpose of the deliverable is to inform and inspire other housing associations and other  houseowners in Europe how to reduce energy consumption in their buildings and how to solve challenges in connection with the financing process and the decision process prior to the implementation.

The target group is primarily administrators of housing associations and owners of apartment buildings

Find full text here.

Torben Esbensen, DEM-Esbensen, te(at)