Driven by population growth and rural migration toward the cities, the demand for affordable housing continues to increase. However, due to the scarcity of urban development space—especially in coastal areas, the supply is limited. As increasing land availability is one of the most effective ways to reduce real estate costs, this interdisciplinary research explores the alternative of urban expansion toward the adjacent marine environment of coastal cities. It focuses on floating residential dwellings from both technological and urban planning perspective, aiming to include the waterfront of coastal cities as viable, sustainable, and affordable alternative for urban development. The research takes on one of the most expensive cities in the world, Tel Aviv-Yafo, as a case study for increasing the supply of affordable housing in addition to vital sustainable future growth in the adjacent marine environment.

This study examines the potential of a new type of floating seawall, made up of retired large-scale oceangoing vessels, to be used in open water and exposed coastal areas. The main objectives of the research are to assess the effectiveness of the floating seawall concept, to determine the contribution of the gap resonance to wave attenuation, and to compare the results of physical tests with those obtained numerically using ANSYS-AQWA. The use of end-of-life ships in this way provides a unique opportunity to extend their life cycle and reduce the environmental and human health risks associated with the current practice of shipbreaking. The research focuses on a multimodule floating seawall configuration, where each module is composed of two hulls that are rigidly connected side by side, with a small gap to induce gap resonance. The results suggest that end-of-life ships can be used as a resource for the construction of floating seawalls for various marine applications. Furthermore, the results demonstrate the positive influence of the gap resonance on the wave attenuation capacity of the seawall, as well as the limitations of the numerical tool in providing realistic values in this region.