The objective of this paper is to introduce a framework that models the cash flow behavior of firms which need to consistently fund risky long-term capital-intensive projects. The model focuses on firms that can potentially fund such long-term projects with their underutilized internal resources such as corporate real estate. We build on the model of Moreno-Bromberg and Rochet [7] in a way that initial liquidity level incorporates the steady cash flow generated from the underutilized assets. The model carries on the basic characteristics which models the firm's growth opportunities (modeled by the operating cash flow). In addition, it not only successfully captures the impact of capitalizing on underutilized assets on the firm's liquidity decision problem, but also provides insights on the timing to reinvest part of the liquid assets into risky long-term capital-intensive projects that might generate future growth opportunities. The potential benefit of implementing such a model is demonstrated by observing the simulated liquidity level using parameters estimated from well-established Japanese firms.