Opening C: Ceiling (room and/or alcove) 22" (559mm) Top of Fireplace Opening D: Mantel Depth (max.) 1r (330mm) 22" Above Fireplace Opening E: Alcove Width 844 (2134mm) Sidewall to Sidewall (Minimum) F: Alcove Depth 36' (914mm) Front to Back Wall (Maximum) G: From Floor 27' (686mm) Top of Firepla