Depending on the package that you are on you can add up to 10 rooms for the Poodle package, 30 rooms for the Beagle package and over 30 rooms for the Husky package
To add or edit your rooms set up - go into the Settings page then click on the [Runs/Rooms] link.
Click into the run/room that you wish to edit and then edit the run name, the size/capacity, you can also take the room offline by deselecting the Bookable setting, you can also hide rooms from the online booking system using the 'Available Online' setting.
We have another article describing the highlighted option below 'Group Runs'.
You can also define what pet types the rooms can cater for, eg if you take small pets a Rabbit or a Guinea Pig could be assigned to the same hutch.