Front of House: anything which happens on the audience side of the curtain is said to happen "front of house". The term "the house" is used to mean either the auditorium, or the audience ("We had a good house tonight"), or even the theatre itself. The Royal Opera House, Covent Garden, is also known as "The House" (with capital letters, of course!)....
See Front of House. 
Foh interj. [ Confer Faugh .] An exclamation of abhorrence or contempt; poh; fie. Shak. 
Family ocular history
Front of house.