Hi! As someone who had to “invent the wheel” last year to enable HubSpot to support a multiple project, multi-unit-per-project Real Estate Marketing & Sales agency - I feel your pain. As the client’s subscription didn’t enable them to create Custom Object I eventually used Parent & Child Companies to represent Developers and Projects. Then I tried using the eCommerce Products list to represent individual units for sale. I won’t bore you with the short comings of this approach, but thankfully HubSpot has heard your prayers!
Open the Settings menu, and under Data Management, you should see the brand new “Object Library.” (Think Custom Object off-the-shelf). One of the options available is “Listings”. You can click on Details to learn more. If you think it meets your client’s needs, click on the View Template button. This will walk you through a detailed explanation of what will be the result of adding this object to your HubSpot instance.
For more information check out the knowledgebase article: Manage objects in the object library