Elaborate on the first draft of the thesis document structure. In general terms, it should contain an introduction, several chapters to distribute research/design, and a conclusion. Try to assemble both main chapters and sub-chapters. Remember, you have to prove the skills both as a designer and as a researcher, you should be able to show yourself as a reflective practitioner. Therefore, both research and design phases must be present in the document. Depending on questions and methodologies the weight of one and the other will be varied significantly.
Highly recommended to start with an abstract of the Thesis (150 words). It should be fundamental to keep structure focuses.