To delete a house type you need to open the house type page under admin and settings. On the right-hand side of this page, there is a red icon of a rubbish bin.
It may be that your user account doesn’t have this functionality approved so you may need to contact your system admin to get a group deleted.
Click the rubbish bin to delete this. You’ll be taken through to a new window warning you that ‘You are about to delete a House type’. Click the green proceed button to delete the house type.
To go back to the house type page without deleting the selected house type, either click cancel or cross to the upper right-hand side of the dialogue box.