A multi-pane window having a low emissivity layer and a photochromic glass. The window includes at least two panes of glass. An outside pane for interaction with the outdoors and an inside pane spaced apart from the outside pane. The outside pane includes a low emissivity coating. The inside pane includes a photochromic glass. The outside pane transmits solar light wavelengths. The photochromic glass is darkened upon exposure to light transmitted by the outside pane.