Data warehouse (DW) design is based on a set of requirements expressed as service level agreements (SLAs) and business level objects (BLOs). Populating a DW system from a set of information sources is realized with extract-transform-load (ETL) processes based on SLAs and BLOs. The entire task is complex, time consuming, and hard to be performed manually. This paper presents our approach to the requirement-driven creation of ETL designs. Each requirement is considered separately and a respective ETL design is produced. We propose an incremental method for consolidating these individual designs and creating an ETL design that satisfies all given requirements. Finally, the design produced is sent to an ETL engine for execution. We illustrate our approach through an example based on TPC-H and report on our experimental findings that show the effectiveness and quality of our approach.