Daylight without an operating sash
Fixed glazing may be useful where the view is the priority. It cannot ventilate the room, so consider nearby operable windows and the household ventilation system.
Select glass for the exposure
A large west-facing opening calls for a different discussion than shaded north-facing glass. Review solar heat gain, visible light, shading, and furnishings together.
Plan for your property
A warmer room is not always a window problem. Look at drafts, shade, orientation, and installation details together. Compare documented product ratings instead of relying on a promised energy saving.