New products in mechatronics, and especially the spreading of microcontrollers, allow a rise in robotic projects of building construction companies. This new context gives the ability to non mechatronic experts to develop building sites robotics. In this paper we will describe the design process of a drilling robot prototype made in our Research and Development department. This specific project was constrained by a lack of specifications, and required fast and low cost methods. We had to face the risk of information loss and mistakes in the appreciation of the results. We intend to explain the design methods and knowledge used in the management of this project. The use of design theories and methods seem to be necessary. Example such as Axiomatic Design or TRIZ can be too strict or too distant from a specific design case. We assume that C-K Theory developed by A.Hatchuel and B.Weil can be a relevant design tool for the development of robotics projects in construction. Thus we wish to present in this article the way we use the C-K Theory to analyze our design process. This design theory is based on two spaces: the knowledge space K and the concept space C. It will reveal the concept and knowledge mechanics in our projects and give clues to produce methods for the management of similar projects such as Single-Task Construction Robots.