Reinforced concrete shear (structural) walls are commonly used as lateral-load resisting systems in high seismicity zones. Typical dominant behavior and failure mode of shear walls are dominated by shear for squat walls and by flexure for slender walls. It is essential to analytically model nonlinear behavior of shear walls as accurate as possible to achieve effective seismic performance evaluation of existing buildings. This research includes a review of nonlinear modeling approaches (e.g., lumped plasticity, distributed plasticity), assembly of a database consisting of conventional reinforced concrete walls with different failure modes, and development of modeling parameters based on experimental data. Also, damage limits in various seismic codes were reviewed and expanded by proposing new damage limits in accordance with the reported test results and Turkish Building Code (2018). The new findings will allow better modeling capability and improved (closer to accurate) damage/failure assessment of shear wall buildings.