To add a new Estate you need to go to Properties on the left-hand navigation, select Estates from the drop-down menu and click the Add new button at the top of the page: 

You can then fill in several bits of information about this new Estate but an Estate Name must be entered in order for the Estate to be created. Once you have entered all the information you want to, click Save: 

The Estate has now been added! You will be able to see all relevant information associated with the Estate as well as view/add any Buildings associated with it via the Buildings tab.  

Please note - if you do not have the option to 'Add new' Estate, this will be because of user role permissions on your Fixflo system. Please speak with an Administrator profile on your account; you can view Administrators via People > Agents and look at the role of each profile.