Application of the engineering economy to evaluating the rent in the low interest rate is an excellent technique. This technique may be adopted to obtain the maximum profit from the rental market by determined in supply and demand curve. In this paper, different cash flows are calculated in various plans by shift equivalence. An AW method in engineering economic may be easily conducted to compare the difference between normal (12%) and low (5%) interest rate. For a house owner, instance, he who can establish an incentive bottom line cost based on mutual benefit by this methodology.