Opening style changes the experience
A side-hung casement, a top-hung opening and a sliding sash use space differently. Think about reach, nearby furniture and the movement of the opening leaf. A familiar appearance does not always mean familiar operation.
A drawing that shows the opening direction is more useful than a front-facing photograph alone. Consider how the window will be used and maintained, and which points need to be checked by the installer.
Proportion before decoration
The balance between fixed and opening sections changes the visible glass area and the pattern across a wall. Wide frames, narrow sightlines and repeated divisions each create a different rhythm.
Look at the full elevation as well as the individual room. Consistent proportions can connect different window sizes without making every opening identical.
Compare the complete specification
Frame material, glass, hardware and seals belong in the same comparison. Material names alone do not tell you the full performance or maintenance requirements of a finished window.
Ask for the proposed specification in writing. The details should make it possible to compare like with like, including the finish, opening arrangement and the responsibilities around installation.