The dense network of charging stations is imperative for promoting the electrification of vehicles. Generating and distributing transportation energy via buildings’ energy systems can be considered a necessity for the transition to electric vehicles (EV). In this paper, it is argued that transportation energy should be included in buildings’ energy balance when designing building-integrated renewable energy system with zero-energy goals. Hence, a statistically inspired, occupant-specific model is developed to quantify the transportation energy demand on the basis of personal mobility requirements and to convert it into the EVs’ charging demand. The usability of the model is shown through a case study, where a new Finnish apartment building with building-integrated solar photovoltaic (PV) system is investigated. The occupants’ personal mobility requirements are predicted and analyzed in the present conditions and three future scenarios describing the electrification of the Finnish passenger vehicle stock. The results support the hypothesis. Even the moderate electrification of the Finnish vehicle stock (250,000 EVs) results in the share of transportation energy of 6–10% in the building's net energy demand. Correspondingly, to maintain the building's energy performance comparable to the case with no vehicle charging included, the size of the building-integrated PV system should be increased by 34%.