We report on the design and growth of asymmetric T‐shaped quantum wires with large one‐dimensional confinement energies. Prior to growth, the optimal structure for a given (110) well width is determined by a calculation. The structures are made by molecular beam epitaxy cleaved edge overgrowth. We demonstrate a confinement of 54 meV in an experimental structure consisting of a narrow (110) oriented GaAs/Al0.3Ga0.7As quantum well overgrown on much wider (001) oriented Al0.14Ga0.86As/Al0.3Ga0.7As wells.