This paper focuses on the conducted electromagnetic interference emissions generated in a building grid-tied PV power system. It emphasizes on the inverter AC side, including the building power grid, as being the interference source and the PV side as the victim circuit, having the inverter as the coupling path. The applicable standards of the grid-tied PV system as being a fixed installation are discussed. The effect of the impedance variation on the performance of the inverter side EMI filter is investigated. In-situ conducted emissions measurement of the PV system connected to the grid, at different points within the system, has revealed the existence of an excessive EMI noise, originating from the building power utility and propagating toward the DC side of the inverter. The conducted emissions waveforms are presented and the results are discussed.