This paper discusses a participatory and evolutionary methodology for information system design and its application to a case from the building construction sector. The methodology supports collaborative design and evaluation of the system being developed. It takes into account that the evolution of the system depends also on the usability problems users encounter in the field. The system evaluation and adaptation become life-long processes. To this end, tools supporting the methodology are developed to facilitate the in-field collection of usability data, the life-long evaluation and development of the system. The discussion is based on examples from a practical case being developed.