Replacing siding before selling a house can be a great way to increase the value of your property. It is an investment that will pay off in the long run, as it will make your home more attractive and desirable to potential buyers. Additionally, replacing siding can help protect against weather damage and reduce energy costs for future homeowners. Ultimately, whether or not you should replace siding before selling depends on factors such as cost versus return on investment and the condition of existing siding.