A method for optimizing the geometrical layout for a façade-mounted solar photovoltaic array is presented. Unlike conventional studies, this work takes into account the finite height of the façade, which is more realistic. The proposed analytical relationships and optimization routine evaluate the best tilt angle and the number of panels such that the whole layout receives the maximum solar radiation, year-round. This is achieved while ensuring that the panels are at a safe minimum distance to avoid mutual shading issues. Validation was performed by simulating the scenarios and comparing the results with manual measurements taken in a three-dimensional drafting program. The method was then used to evaluate designs for facades with a variety of orientations, hypothetically located in Auckland, New Zealand. For this case study, the per-panel and total year-round energy accumulation associated with the number of panels were determined. The results showed that more panels can be integrated into constrained fields by sacrificing the year-round best value of the tilt angle. Therefore, increasing the number of panels may decrease the energy accumulation performance.