A coated glass pane comprising at least the following layers in sequence: a glass pane; an underlayer; and at least one layer based on silica and/or an organo silica, wherein: said at least one layer based on silica and/or an organo silica is obtained by partially or completely converting at least one layer based on one or more silazane; and a surface of said at least one layer based on silica and/or an organo silica has an arithmetical mean height of the surface value, Sa, measured in accordance with ISO 25178, of at most 2 nm; and said at least one layer based on silica and/or an organo silica has a thickness of at least 10 nm, but at most 800 nm, wherein the underlayer comprises, in sequence from the glass pane: a lower anti-reflection layer; a silver-based functional layer; and at least one further anti-reflection layer, wherein the lower and/or further anti-reflection layer comprises: at least one dielectric layer based on an (oxy)nitride of Si and/or an (oxy)nitride of Al and/or alloys thereof; and/or a metal oxide such as an oxide of one or more of Ti, Zr, Zn, Sn, In, and/or Nb, such as an oxide of Zn and Sn. a glass pane; an underlayer; and at least one layer based on silica and/or an organo silica, wherein: said at least one layer based on silica and/or an organo silica is obtained by partially or completely converting at least one layer based on one or more silazane; and a surface of said at least one layer based on silica and/or an organo silica has an arithmetical mean height of the surface value, Sa, measured in accordance with ISO 25178, of at most 2 nm; and said at least one layer based on silica and/or an organo silica has a thickness of at least 10 nm, but at most 800 nm, wherein the underlayer comprises, in sequence from the glass pane: a lower anti-reflection layer; a silver-based functional layer; and at least one further anti-reflection layer, wherein the lower and/or further anti-reflection layer comprises: at least one dielectric layer based on an (oxy)nitride of Si and/or an (oxy)nitride of Al and/or alloys thereof; and/or a metal oxide such as an oxide of one or more of Ti, Zr, Zn, Sn, In, and/or Nb, such as an oxide of Zn and Sn. said at least one layer based on silica and/or an organo silica is obtained by partially or completely converting at least one layer based on one or more silazane; and a surface of said at least one layer based on silica and/or an organo silica has an arithmetical mean height of the surface value, Sa, measured in accordance with ISO 25178, of at most 2 nm; and said at least one layer based on silica and/or an organo silica has a thickness of at least 10 nm, but at most 800 nm, wherein the underlayer comprises, in sequence from the glass pane: a lower anti-reflection layer; a silver-based functional layer; and at least one further anti-reflection layer, wherein the lower and/or a lower anti-reflection layer; a silver-based functional layer; and at least one further anti-reflection layer, wherein the lower and/or further anti-reflection layer comprises: at least one dielectric layer based on an (oxy)nitride of Si and/or an (oxy)nitride of Al and/or alloys thereof; and/or a metal oxide such as an oxide of one or more of Ti, Zr, Zn, Sn, In, and/or Nb, such as an oxide of Zn and Sn.