Integral Building Envelope Performance Assessment

Completed (1996 - 1999)


A good building envelope design should be the result of a systematic approach, checking all relevant elements. A new approach would include all the aesthetic and physical properties to be fulfilled by that envelope, integrated with the function of the building as a whole.

The objective of this annex was to develop the methodology and the performances which would support the integral design and evaluation process for building envelopes with the aim of realising significant energy, environmental and comfort design. Although the envelope in itself is a crucial element for the overall performance of the building, the interaction with other building components and the climatic control systems are of equal importance. Therefore, the emphasis of the project was on the overall performance of the building seen from the perspective of the envelope. While the focus was on energy efficiency, high quality was also the aim when considering aspects like durability, comfort, acoustics, and moisture.

The project was divided into two areas of research:

Assessment Methodology

The objective here was to develop a comprehensive assessment methodology based on performance criteria, leading to rational strategies for the optimization of building envelopes with respect to their energetic and environmental qualities. The methodology aimed to focus on ways to apply new concepts and materials, making use of existing (inter-)national experiences and guidelines. The methodology should be of use in the different stages in the design process. The assessment methodology was based on performance criteria for the envelope and its components, taking into account the relation between the envelope, climate, the building and systems. The aim was to stimulate the creative use and combination of new technologies.

Evaluation Methodology and Design Tools.

The objective of this research area was to test, further develop and evaluate integral design tools, by application on test cases, in particular, tools which contribute to the optimization of use of renewable energy, energy conservation and to a high quality thermal and visual indoor comfort. These tests would also serve to demonstrate the value of the developed assessment methodology. The test cases varied from (re-)evaluation of existing envelopes, new design, or renovation. The test cases comprised small scale tests (laboratories or site tests), component and system simulations and full scale demonstrations.

Operating Agent

Prof Hugo Hens
K.U. Leuven
Department of Civil Engineering
Laboratory of Building Physics
Kasteelpark Arenberg, 51
B-3001 Leuven
Tel: +32 16 32 13 44


Belgium, Canada, Denmark, Finland, The Netherlands, Sweden, and Switzerland


  • Technical Synthesis Report - Annex 32 (PDF 2.3MB) Edit Publication
    Author: Peter Warren
    Publisher: Faber Maunsell Ltd
  • Advanced Envelopes: Methodology Evaluation and Design Tools, Final Report Volume 3 Edit Publication
    Author: Paul Baker, Dirk Saelens, Matt Grace, Takashi Inoue
  • Development and Optimisation of Building Envelopes for Existing and New Buildings, Final Report Volume 2 Edit Publication
    Author: Sven Svendson, Claus Rudbeck, Horst Stopp and Hannu Mäkelä
  • Building Envelopes in a Holistic Perspective: Methodology, Final report Volume 1 Edit Publication
    Author: Leo Hendriks and Hugo Hens