A rotor blade assembly for a wind turbine and a method for increasing a loading capability of a rotor blade within a maximum load limit for a wind turbine are disclosed. The rotor blade assembly includes a rotor blade having surfaces defining a pressure side, a suction side, a leading edge, and a trailing edge extending between a tip and a root. The rotor blade assembly further includes an extension connected to a surface of the rotor blade, the extension having at least one design characteristic configured for increasing a loading capability of the rotor blade within a maximum load limit for the wind turbine. The design characteristic is one of extension length, extension width, extension curvature, span-wise extension location, chord-wise extension location, or extension angle with respect to a chord line of the rotor blade.