These are sketches of Knights Province houses.
This sheet is composed of many (but not all) wip houses. Many houses are still missing. You may note that several houses are made by different artists, even more, some are duplicate because the design was not fit for the game. It takes time, trial and error to arrive to the final design. Almost all houses will change along the development and conversion to 3D. You can read more about the process of creation of individual sketch in this article.