Direct answer: glass is decisive
The frame matters, but glazing strongly affects insulation, noise, security and solar control. Choose glass according to the real problem in each room.
Thermal insulation
Low-emissivity glass helps reduce heat loss in cold areas. In sunny façades, solar control may be equally important.
Noise reduction
For noise, acoustic laminated glass, asymmetric thicknesses and airtight windows usually matter more than simply adding more panes.
Security
Laminated glass improves resistance to impact and is useful for ground floors, terraces and exposed openings.
Common mistakes
Choosing only by price.
Using the same glass in every room.
Ignoring the shutter box.
Forgetting orientation and sun exposure.
Practical recommendation
Define the main issue for each window: cold, heat, noise, security or condensation.