Building an app for house rental typically requires a team of developers with various skill sets. The number of developers needed depends on the complexity and scale of the app you want to build. Factors such as the number of features, integration with other systems, user interface design, and backend development all contribute to determining the required team size. Generally, a small to medium-sized house rental app may require a team of 2 to 5 developers, including frontend developers, backend developers, and possibly a designer. For larger and more complex projects, the team size may need to be larger to ensure efficient development and timely delivery.