In spite of the increasing use of the Web as a product information source, there is not much research on how architects and other building professionals use this source, which problems they encounter, what changes they would like to see, what opportunities and challenges this emerging media holds. As yet, there has not been much research examining these issues. This study tackles these issues. It contributes to a greater understanding of the relationship between design and information, particularly electronic information. The first phase of the research involves conducting a web-based survey among mainly architectural practitioners. The primary objectives of the survey are to collect information as to how architects are using web-based building product information, and to explore the strengths and weaknesses of existing building product Web sites. The second phase of the research is to develop a prototype utilising the data collected from the survey. The prototype called Interactive product Selector (IPS) is a highly interactive Web-based environment developed using the combination of CGI/Perl, Java, JavaScript and VRML technologies. The IPS acts like a decision support system offering an intuitive user interface, visual product support, the ability to self-navigate products in three-dimensions, the means to make comparisons between different building products. The third phase is the user testing of the IPS. The system was presented to three architectural practitioners to obtain feedback. The significance of this phase was that it helped identify possible uses for the IPS and raised new issues with on-line product information in general beyond the ones addressed in the survey.