Yes, you can hide your House scores at any time. Hiding house scores can be useful if you want to make the winning house a surprise. Some schools toggle off their school's scores on the last day of their round, then toggle them back on to show the winner as a surprise at the end of the day.
1) Sign in as an Admin
2) Click the left side Houses menu
3) Toggle on Hide all House scores to hide the current scores on all displays immediately
NOTE: The house score are always visible in Admin mode. They can be hidden in the teacher and student apps as well as the Houses Displays.