EBC Annex 36 Retrofitting in Educational Buildings - Energy Concept Adviser for Technical Retrofit Measures


Status: Completed (1999-2003)

Operating Agent: Hans Erhorn, Frauhofer Institute of Building Physics, Nobelstr. 12, D-70569 Stuttgart. Germany.
Tel: +49 711 970 3380
Fax: +49 711 970 3399

Email: erh[at]ibp.fhg.de

Website: www.annex36.com


Educational buildings such as kindergartens, schools, training centres and universities display many similar design, operation and maintenance features in many of the IEA countries. For example, many have similar structures, often need to be retrofitted, and have high energy consumption. Because of the level of similarity that exists within this building sector, experiences gained in developing different approaches to combat similar problems, especially during retrofitting, can easily be transferred to other countries.

Two overwhelming similarities amongst these types of buildings are the high energy consumption and necessity to retrofit many buildings within this sector. However, studies have shown that during retrofit energy saving measures are only rarely applied, because of a lack of knowledge by the decision makers regarding the investments and the efficiency of potential energy saving measures. Because of the lack of information, in many cases decisions are made that do not accurately take into account energy saving aspects. There are no "rules of thumb" to enable a quick and easy estimation of the levels of required investment, before an analysis of the building structure in detail.

Therefore the development of an 'energy concept adviser' for economical retrofit measures would be useful during the planning and realization phase, on the one hand to help the investor to find the energetically and economically most efficient energy saving measures, and on the other to prevent him from exaggerated expectations. The 'adviser' should be applicable during the entire retrofitting phase to ensure that both the calculated energy savings and the economical success will be achieved after retrofitting. This annex therefore aimed to develop such a tool.

The objectives of this project were:


To develop simple prediction tools for retrofit concepts which allow the decision maker to evaluate integrated construction, installation and lighting measures


To develop a 'concept adviser' to analyse existing buildings and their economic efficiency, and to supplement this by simple methods for testing the efficiency of the applied measures.


To promote energy and cost efficient retrofit measures and to support the decision makers in evaluating the efficiency and acceptance of available concepts

There were four research areas:-

Selection and Analysis of Existing Information

In this research area existing information and knowledge in the IEA member countries was collected and analysed. The state-of-the-art knowledge was documented and differences between the countries identified to make evident existing gaps in the knowledge, and to point out appropriate solutions, which were elaborated within the other research areas. The work mainly focused on requirements, guidelines, building types, technologies, benchmarks and decision criteria. Experts from the participating countries collected and prepared extensive information on special topics to be provided for the project participants as knowledge transfer.



A report consisting of a catalogue of benchmarks and solutions for different educational building types (technologies, materials etc)

A working Document on parameters / design guidelines for good learning and teaching environments

A working Document on design criteria (e.g. economic analysis, functional requirements).

Case Studies

The project case studies included a collection both of exemplary completed and of 8-10 "new", innovatively retrofitted buildings (from the late 90's) of which a few were still under construction and due to be finished in 2000 - 2002. The case studies included schools, institutional and laboratory buildings, with innovative energy saving measures, daylighting and artificial lighting systems with advanced control systems. Measured performance data included temperatures, illuminances and other comfort criteria of the interior space, heating, cooling and electrical lighting consumption, the power consumption of the installations and control systems, the total building energy consumption and the indoor air quality. User acceptance of environmental conditions was assessed through questionnaires. In a design forum, national concepts of planned demonstration projects were reviewed and compared to the experience gained in the other countries.


– Design Guidelines for retrofitting of educational buildings

– Case Studies Report with documented evidence of energy saving potential of
   retrofitting processes

Software Development and Analysis Methods

The design tools used included selected tools, ranging from simple spreadsheets to advanced computer programs that took into account the impact of light, heat and cooling in buildings. Work on simple and integrated design tools included validation as well as the improvement of user interface and optimization of calculation procedures. Work on analysis methods focused on short-term measurements and on the comparison of audit procedures and evaluation measures.



A working Document on simple calculation tools for decision makers by setting up benchmarks, regulations and spreadsheets


A report on energy audit procedures including short-term measurements for components and systems (comparison and recommendations)


A working document including a list of principles and systems to simulate in retrofitting projects and an evaluation of design tools (list and recommendation)


A working Document on operating procedure including checklist (manual) and evaluation of special measures by means of energy auditing, short-term measurement and questionnaires.

Documentation and Dissemination

Documents and dissemination focus on the transfer of the research results to be used by practitioners. Several methods were used for information dissemination. Besides the conventional ways of dissemination, such as newsletters and practice articles, media like the Internet were also used. Apart from publications written in English, publications in the languages of the participating countries were also produced.


–  Website
–  Articles
–  Newsletters
–  Conference papers.

Joint Working Group "Energy Concept Adviser"

All the research areas provided their results as input to the joint working group. Based on the results the joint working group developed an electronic interactive source book (The 'Energy Concept Adviser' (ECA)). A central database includes all project results and allows the user to obtain extensive information, according to his/her individual focus of interest, on design inspirations, design advice, decision tools and design tools. Thus, the user is able to increase his knowledge in the respective field of interest quickly and reliably. The user has the choice of analyzing design scenarios himself and/or use the pool of experience gained in the case studies projects to access information on energy saving potentials and requirements.


– Electronic interactive source book including design inspirations, design advice,
   decision tools and design tools.

An extension to the Joint Working Group was approved in 2004, with the remit to provide national versions of the ECA.

Participating Countries: Denmark, Finland, France, Germany, Greece, Italy, Poland, USA, UK



Technical Synthesis Report: Retrofitting in Educational Buildings: Energy Concept Adviser for Technical Retrofit Measures
Edited by Richard Barton
UK, Faber Maunsell Ltd, 2007 Download

Case Study Reports
Edited by Ove Morck, Hans Erhorn
September 2003
Printed copies can be ordered at:
Fraunhofer Institute for Building Physics IBP Department Heat Technology
Nobelstraße 12, D-70569 Stuttgart
Phone: +49 (0) 711/970-3360 Fax: +49 (0) 711/970-3399
email: andreas.reith@ibp.fraunhofer.de
Further information 

Energy Concept Adviser
2005 (ECA program, ECA manual)
Further information available at the Annex 36 website.

KULU – a tool for commissioning
(KULU program, KULU manual)
Further information available at the Annex 36 website. 

State of the Art Overview: Questionnaire Evaluations (Working document)
edited by Tomasz Mroz, Hans Erhorn

Overview of Retrofitting Measures (Working document)
edited by Tomasz M Mroz, September 2003

Calculation Tools for the Energy Concept Adviser
Fritz Schmidt et al, July 2004

Calculation Tools for the Energy Concept Adviser, Appendix C: How to use the ECA calculation models
Fritz Schmidt et al, July 2004

Calculation Tools for the Energy Concept Adviser, Appendix B: KULU WINDOW Instructions
Fritz Schmidt et al, July 2004

Energy Audit Procedures
edited by Jan de Boer, December 2003