This article looks at the top three factors to consider before investing in a buy to let property, it helps you decide which properties are good or bad and also looks at ideas on exactly what you should look for and at when searching for a new property. Cash on Cash Return - This represents the ratio between the property's annual cash flow (usually the first year before taxes) and the amount of the initial capital investment (down payment, loan fees, acquisition costs). Location, property type and size can affect how much you can reasonably charge on a rental property