The members of the pre-fabricated single-family house industry perceive problems securing the quality of incoming material. Thus the implication is that they need to carry out a quality inspection and adjust the softwood timber as it arrives at their facilities in order to fit the production. Furthermore, due to the intense competition among companies in the pre-fabrication industry, there is a focus on reducing non-value-adding activities such as deficiencies. Consequently, the purpose of this study is to propose a number of propositions regarding quality deficiencies in softwood timber for the pre-fabrication of single-family houses. This study, conducted through interviews based on the theoretical aspects of properties, quality inspection and quality deficiency formulates seven fundamental propositions regarding quality deficiencies in this industry. The main differences among the companies studied are their purchased volume and extent of information and communication technology support in production. This fundamental description of quality deficiencies regarding softwood for the pre-fabrication of single-family houses will enable companies to focus on quality issues with their raw-material suppliers and thereby increase the competitiveness of softwood timber as a construction material in the industry.