Business requirements are essential for developing any information system, including a data warehouse. However, the requirements, written in natural language, may be ambiguous and imprecise. This paper offers business requirement formalization metamodel, which defines business requirements according to a certain pattern, specific to data warehouse systems. We also propose a method to create a conceptual model of a data warehouse, based on the knowledge about requirements and conceptual models of previously developed projects. The method is extended by providing evaluation of possible ways of selecting conceptual model of existing data warehouse projects.