Historic buildings make up a considerable part of our building stock (one fourth for Europe). They are the trademark of numerous cities, and they will only survive if maintained as a living space. This means, that in order to save this heritage for future generations, we need to find conservation compatible energy retrofit approaches and solutions, which allow to preserve the historic and aesthetic values while increasing comfort, lowering energy bills and minimizing environmental impact.

In the last 10 years a shift in paradigm could be observed: While in times of the first EPBD, a strong opposition from conservators and architects could be observed – "don't touch these buildings" – there is growing a new openness, a much more constructive approach – "let's find the right solutions together". Examples for this development are last but not least the installation of the International Scientific Committee on Energy and Sustainability within ICOMOS and the development of "Guidelines for improving the energy performance of historic buildings" (EN16883, now under final vote) by the CEN TC 346 on Conservation of Cultural Heritage.

Now is an important moment to identify and promote good approaches and solutions.

Standard energy saving measures are often not compatible with preserving the historic buildings’ character, nevertheless the energy performance can be improved considerably if the right package of solutions for the specific building is identified. Actually, also the possibilities to use solar energy in historic buildings are more than one might expect in a first moment, if solar panels/collectors

  • are compatible in colour and design to established (roof) material
  • are integrated in an architecturally attractive way
  • can be positioned in parts of the building where they are not as visible
  • panels and mounting systems are reversible
  • stand-alone solar systems are not interfering aesthetically with the building itself are possible

Realised examples show that a reduction of "Factor 4" (i.e. reduce the energy demand by 75%) and beyond is possible also in historic buildings preserving their heritage value – depending however on the specific case. While defining a minimum performance as for “standard” buildings does not make sense, when looking at the specific building, the design team should not “stop thinking” too early! A considerable reduction in demand – also thanks to optimisation of passive solar use – opens up the possibility to go with active solar contribution towards nZEB.

SHC Task 59 is a collaborative task with IEA EBC Annex 76.


The Objectives of the Task are to

  • Develop a solid knowledge base on how to save energy in renovation of historic and protected buildings in a cost efficient way.
  • Identify the energy saving potential for protected and historic buildings according to typologies of building studied (residential, administrative, cultural…)
  • Identify and assess replicable procedures on how experts can work together with integrated design to maintain both the heritage value of the building and at the same time make it energy efficient
  • Identify and further develop tools which support this procedure and its single steps
  • Identify and assess conservation compatible retrofit solutions in a “whole building perspective”
  • Identify specifically the potential for the use of solar energy (passive and active, heating, cooling and electricity) and promote best practice solutions
  • Transfer knowledge

In the strategic plan it is stated that to realize this huge potential for solar heating and cooling in the building sector, it is essential to integrate solar technologies into the built environment in an appropriate way. Solar based renovation of existing building stock is listed as one of the most important activities to achieve this.