Due diligence refers to investigating facts about the condition of the property, both financial and physical, as well as the area the property is located in. Due diligence is a required and essential step in the sale of real estate.A real estate attorney can help the process go smoothly. The due diligence period in a real estate contract is defined as a buyer's obligation to thoroughly investigate a property within a specified time. 3 for the due diligence requirements. Let Nishad Khan, P.L. offer the legal assistance you need to perform your due diligence in real estate; contact us today for a consultation. Generally, the due diligence period is ten days from the binding date, but this can be negotiated. The due diligence letter must not contain any contact information for the state of Florida. Unless there's an issue with how the contract to purchase was drawn up, the due diligence is not refundable. Due diligence is the process that most buyers undertake to ensure that the home they are purchasing meets certain standards for safety, soundness, and value.