Accelerated urbanisation generates large quantities of construction and demolition waste (CDW). Most of this waste is inert and poses no environmental risk. In France, according to article R541–8, 72% of this waste is inert, and 26% is non-hazardous. Landfilling CDW involves ecological risks such as water and air pollution and a disastrous visual impact on the landscape. Concrete waste is the largest component of CDW, producing recycled gravel (RG) and recycled sand (RS). These recycled aggregates (RA) are natural aggregates (NA) coated with around 30 to 40% of old mortar. For many years, numerous researchers have studied the characteristics of concrete made with RA. However, RA generally contains non-hazardous waste (NHCDW) such as bricks, bitumen, earthenware, tiles, plastics, etc. There is a general lack of knowledge concerning the effects of NHCDW in RA. No more studies are available focusing on the impact of NHCDW on the behaviour and acceptability criteria of CDW materials used in activities such as backfilling, building, and landscaping. This study is part of the European project 101091679-MOBICCON-PRO (MOBile and Innovative Circularity for CONstruction PROducts)-HORIZON-CL4–2022-TWIN-TRANSITION-01). It aims to study the effect of these non-hazardous wastes on mortars’ physical and mechanical properties. The main objective is to establish threshold values for NHCDW (sand) to guarantee the required mortar properties. The experimental approach involves characterising NHCDW sands (density, porosity, water absorption) and designing mortars containing at least 30% of these sands with different proportions. The main properties studied are mechanical strength, porosity and density of the mortars.