This paper investigates the impact of transmittance level and layout variations of semi-transparent photovoltaics (STPV) on both energy performance and occupancy-based visual and thermal comfort, simulating a reference office with a fully south-oriented glazed surface. Four transmittance levels (20, 30, 40 and 50%) were investigated, first uniformly distributed on the full glazing (i.e., one specific transmittance for the entire glazing) and then considered in combination (i.e., with the glazing divided in equal-height bands with different transmittance levels). Simulations were conducted in three climatic conditions: temperate (Geneva), hot-arid (Casablanca) and cold (Helsinki). Following the proposed energy and occupancy-based visual and thermal comfort analysis, the best design option for both Geneva and Helsinki climate resulted the 2-level STPV design variation with 50% visible transmittance on top of the glazing. In Casablanca, the 1-level design variation with the lowest visible transmittance (20%) uniformly distributed resulted as the best choice. This work, besides offering a first exploration of the relationships between climatic context and STPV design variations, describes a spatial multi-criteria analysis method that could be applied for the evaluation of other glazing technologies.