Unmanned aerial vehicle (UAV) sensing technologies have become increasingly accessible in usability and affordability. The availability of low-cost and highly accurate site scanning technology offers advantages to small scale landscape design projects for site surveying and post occupancy evaluation. Using a private landscape design commission in Baltimore, MD as a case study, this paper explores the application of UAV generated 3D scan models in the design process. The paper reports on methods used to incorporate scan models into a digital design workflow, while discussing opportunities and constraints in their application for design and evaluation. The case study demonstrates the use of scan models as digital twins of project sites in the landscape design process and positions UAV sensing as a feasible approach to generating feedback loops for design process and construction outcome.