I agree with the previous posters. If the rent that you would be charging for the unit is at the lower end of what is expected for the size and location (ie. below the average) then you likely would not have a problem finding a tenant who did not care about an in unit washer/dryer. If you are looking to get a rental rate that is at or above the average for that location, tenants are going to be more selective about the amenities (and willing to pay for them). Also you may want to check with the condo or co-op board about the option of adding one yourself, although it is rare, occasionally it is permitted as long as you go about it in the correct manner. There are combined washer/dryer units that are popular (because they save space) for this purpose.