High reset energy is an ongoing issue for phase-change memory (PCM) devices. Prior work demonstrates that smaller PCM switching volume and thermal isolation can reduce the reset energy. In this paper, we fabricate and measure a planar confined PCM device with a multilayer dual-layer stack (DLS) of SiO2/Al2O3 insulator. Devices with contact area of 500 $\times $ 20 nm and lengths of $2~ {\mu }\text{m}$ show exceptionally low reset energies of 18.25 ± 15.8 pJ and low reset current densities of 0.94 ± 0.51 MA/cm2. Implementing the DLS enables a 60% reduction in reset energy compared with SiO2-isolated devices.