Compare frame and glass area
A broad slider can put a substantial glass area on a sunny wall. Discuss solar heat gain and exterior shading before selecting a glass package.
Keep drainage working
Track maintenance and unobstructed drainage matter. Ask for the manufacturer’s cleaning instructions and avoid sealing drainage openings in an attempt to stop a draft.
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.