Fungal defacement on the inside surface of exterior walls is a common complaint in buildings in both cool and warm climates. The first part of this paper discusses the method by which the con-ditions for mold growth on inside surfaces were handled in the building community. Then, a short description of a performance based approach follows, succeeded by an analysis of all hygrothermal parameters that intervene in prevention. The paper ends with a discussion of the performance requirements to minimize the risk of fungal defacement. The occurrence of fungal defacement is governed by a combination of ten parameters. The inside and outside climate and the vapor quan-tity released or removed inside are stochastic parameters that need to be considered when defining minimum thermal performances or ventilation flows to avoid fungal defacement.

• fungi and molds in buildings and their envelopes : Fungal defacement
• mathematics: stochastical modeling and analysis
• performance-based building codes and standards
• risk analysis

1. A comparison of different techniques to quantify moisture content profiles in porous building materials
2. Application of a new type of air and vapor retarder in a self-drying sloped roof with a cathedral ceiling
3. Building envelopes in a holistic perspective
4. Condensation risk assessment
5. Determination of the liquid water diffusivity from transient moisture transfer experiments
6. Evaluating the thermal performance of active envelopes
7. Heat and moisture response of vented and compact cathedral ceilings: a test house evaluation
8. Heat, air and moisture transfer in insulated envelope parts. Final Report, Volume 1, Modelling
9. Heat-air-moisture design of masonry cavity walls: theoretical and experimental results and practice
10. Hygric properties of a new humidity controlled vapor retarder
11. IEA Annex 14: Condensation and Energy
12. Inquiry on HAMCAT codes
13. Interstitial condensation due to air leakage: a sensitivity analysis
14. Microscopic analysis of imbibition processes in oolitic limestone
15. Modeling. Final Report
16. Performance prediction for masonry walls with EIFS using calculation procedures and laboratory testing
17. Performance-based development of a thermally insulated pitched roof system
18. Pitched roofs, heat-air-moisture transport in tiled and slated roofs with the thermal insulation at rafter level
19. Simulating non-isothermal water vapour transfer: an experimental validation on multi-layered building components
20. The influence of soil moisture in the unsaturated zone on the heat loss from buildings via the ground