Correlation-based evaluation tool that enables heating needs in residential buildings to be assessed. It has been developed in the framework of the PASSYS project of the European Commission DG XII. The PASSPORT tool has close links to a preliminary European Standard for calculating energy requirements for heating in residential buildings, because the PASSYS project and a working group of the European Standardisation Committee (CEN TC 89 WG4), having similar concerns, have worked in close collaboration. A choice is offered to the user of PASSPORT: either to follow strictly the CEN Standard or to call upon some features, intended to improve the accuracy of the results (especially in the case of passive solar buildings), but not retained by CEN for implification reasons.

The method is based on a steady-state energy balance for the building zone, with an allowance for external temperature variations and a utilisation factor taking account of the dynamic effect of internal and solar gains. The main improvements in comparison with previous simplified methods are listed below. The gain utilisation factor is given as a function of the gain to load ratio (GLR) and an inertia parameter t (time constant of the building or of the zone). The method treats separately two phenomena associated with intermittent heating: decreased losses due to lower inside temperatures and reduction in of the utilised gains to take account of periods when the building is not heated. Two intermittency factors are obtained from formulae taking account of the heating pattern and the time constant of the building. To deal with multi-zone passive solar buildings, uniform temperature zones are defined; then the calculation method is applied to each zone. To take account of the interaction between the zones, an interactive procedure is used to solve the heat balance for all zones.


heating requirements, passive solar, residential buildings, standards



Expertise Required

Basic understanding of heating in residential buildings.


Many throughout Europe.


housing designers, architects, researchers


Building thermal and physical description.


Heating requirements, gain to load ratio, utilization factors.

Computer Platform

MS-DOS, minimum 286 IBM compatible.

Programming Language



Easy to use, assessing heating requirements in the context of the CEN standards.


DOS-based interface. Correlation-basis may mean that some configurations may not be able to be accurately simulated.



University College Dublin


Energy Research Group
Richview, Clonskeagh
Dublin 14


+353 (1) 269-2750


+353 (1) 282-8908




PASSPORT has been created by M. Santamouris and Y. Sigalas within the PASSYS Project of the European Commission DGXll for Science Research and Development of the European Commission. PASSPORT is available at IR� 80.00, ECU 100.00, US$ 120.00 including P & P. PASSPORT software and manual are distributed on one 3-1/2" diskette. For further information, visit the web site.