The average minimum cost per finished square foot of engineered quartz counters is $38. The average maximum cost per finished square foot of engineered quartz counters is $55. In addition to the cost of the slab of engineered quartz to be installed as a counter, there are some other costs associated with this home remodeling project. Supplies such as epoxy and adhesives add an average of $2.20 per finished square foot of surface area.