Several works estimate the photovoltaic potential using light detection and ranging data. However, such data may not be available in some countries. This paper presents a novel methodology to estimate the potential photovoltaic spatial distribution considering shading effects caused by tall buildings. The proposal uses reduction factors and buildings'3D models. Shading effects are analyzed in representative blocks for the study area. The proposed method is applied in an urban zone in Sao Paulo in Brazil, where tall buildings and residential houses are built. The estimate indicates a reduction of 3.2%in the PV potential due to shading effects. Furthermore, the proposed method allows the calculation of the daily average PV potential. The potential photovoltaic estimate is helpful for distribution utilities and governmental authorities to perform hosting capacities and sustainable planning studies.