The title offers a clue what the author wants to say. It seems like the book is a manual for building a house the right way. The drawings and pictures in the book reveal big projects which suits the bourgeoisie but not the lower classes. The houses look expensive and must be designed for a person of importance.
Each aspect of the building is written down. From how to design a floor plan to the structure of the garden.
The plans offer a wide range of different kind of structures. There are maybe explanations when to use which form. The book could be an atlas of different possibilities or something like an architectural dictionary. A collection of architectural knowledge.
The Title says “How to design a house” but he writes more about the principles and structures than a straight forward manual.
The book is quite big and resumes in a second volume. There is a lot of information to be shared and the size could be an indicator for the importance of the book.
The author himself was an architect.