A blueprint thesis refers to a statement that highlights the main ideas to be covered in an essay or article. It serves as an introduction and offers important points or a brief explanation of the subject matter.
A writer uses the blueprint thesis to define the structure of his final piece of essay. It is a writer's plan, which enables the writer to avoid unnecessary rewritings of a single piece of material. This can be compared to an architect's plan, which helps in avoiding unnecessary demolitions during the construction process in order to provide for modifications. It is usually a single statement.