The Green Mountain region of Libya experiences a persistent housing problem with regard to damp, regardless of the quality of the design, materials used, the construction practice and policy. This investigation into the factors influencing the performance of concrete housing to combat penetrating damp identified a broad range of factors: technical, managerial, economic, socio-cultural design and climatic issues. Consideration was given to specific national factors impacting on housing design and construction such as housing policy. The applicability of factors was confirmed by primary data collected from a householder questionnaire and a photographic observation survey of the condition of damp houses. Primary data were combined with secondary data in order to develop a more complete picture of the phenomenon under investigation. The analytical hierarchy process (AHP) technique was applied to construct an evaluation hierarchy of factors affecting the performance of houses in a Albeida city in North Eastern Libya. Factors were weighted and evaluated through interviews of construction professionals and self-build house owners. Results were integrated using the mathematical technique of AHP and a model of the most significant factors proposed. While the technique has been widely applied in various construction disciplines as a multiple criteria decision making technique, this study is the first to apply the technique as an analytical tool for understanding in depth a specific problem of construction and housing rather than for deciding a course of action. The results show that the issue mainly affects middle income and poor householders. Construction and socioeconomic design factors are the major causes of the presence of penetrating damp, together with the financial constraints of the owners. Surprisingly, management and climatic factors have less impact on the occurrence of damp. The model was subsequently validated in a sample of houses suffering from penetrating damp in Massa. This indicated that caution should be exercised regarding the application of AHP to the owners' judgments and the transferability of results. Whilst the findings of this research can assist decision makers in similar situations to identify appropriate assessment criteria for the construction of future housing projects, further investigation into the applicability of AHP in comparison with other methods is recommended. IV Acknowledgements I am most grateful to Allah Almighty for providing me with the patience and making it possible to produce this piece of work. I am also thankful to many people for their help and assistance, both directly and indirectly.