Much work on the potential of including evaporative cooling in building envelopes has been carried out, for example evaporative roofs, green roofs, and pond roofs. This principle is particularly effective in hot climates with water availability, and it has proved to be effective when used in low-cost energy retrofits in low performance buildings. In this work a new approach is proposed: the addition of a layer of a hypothetical super adsorbent material with a wetting system on the external side of the wall and its effect on the cooling loads is evaluated for different climates and building envelope build-ups. The efficiency of the system is evaluated using the software tool WUFI Plus, which is used to perform the building energy simulation of the building considering coupled heat and moisture transfer in the building envelopes. These promising preliminary results could be used to evaluate the development of low budget retrofit solutions for low performance buildings subject to relevant heat waves, improving the climate resiliency of existing building stock.