Between 2000 and 2015, annual electric peak demand in Kuwait has doubled to 15000 MW and the Ministry of Energy and Water expects this number to double once more by 2030 attributing 70% of this growth to new housing projects. Within this context, this manuscript evaluates the effect of incorporating PCM-wallboards in low-rise air-conditioned residential heavyweight buildings in Kuwait. Using an EnergyPlus single-zone model, a parametric study is performed considering several window-to-wall ratios (WWRs), different solar orientations and some PCM-wallboards configurations. The main study goals are to: (i) explore the validity of a single PCM-wallboard solution that can be universally applied throughout residential buildings in Kuwait; (ii) evaluate the impact of PCM-wallboard on the reduction of both cooling demand and peak-loads; (iii) provide some guidelines for incorporating PCM-wallboards in Kuwait. Following an extensive parametric study, a 4 cm thick PCM-wallboard with a melting-peak temperature of 24 °C yielded the lowest annual cooling demand across a variety of room orientations and WWRs assuming cooling setpoint of 24 °C. Its implementation led to annual cooling energy savings of 4%–5% across all the case-studies. Regarding the impact throughout the year, cooling demand and peak-loads can be reduced by 5%–7% during summer months. The average daily cooling loads can be reduced by 5%–8%.