The four decisions.
Pane count: double-pane covers most temperate-climate residential. Triple-pane belongs in cold climate (IECC zone 5 and colder) or where acoustic isolation matters. Each additional pane adds insulation, weight, and roughly 18mm to the sightline.
Low-E coating: soft-coat sputtered Low-E performs better and is standard in new IGUs. Hard-coat Low-E is more durable but lower performing; used in storm windows and secondary glazing. Coating position inside the IGU optimizes for cold-climate retention or hot-climate rejection.
Gas fill: argon between panes is the default and adds minor insulation versus air. Krypton outperforms argon in tight cavities (premium triple-pane). Air is the legacy option and is no longer standard on quality IGUs.
Safety class: tempered glass is code-required for doors, sidelights, and large low-set windows. Laminated glass is required for impact-rated assemblies and is the only path to acoustic glazing above STC 40.
Common questions.
- Is triple-pane glass worth it?
- Triple-pane is worth it in IECC climate zone 5 and colder, or where acoustic performance matters. In zones 1 to 4 the energy payback on triple-pane over a good double-pane is slow, and the added weight raises hardware cost.
- What is the difference between soft-coat and hard-coat Low-E?
- Soft-coat (sputtered) Low-E performs better but must stay sealed inside the IGU. Hard-coat (pyrolytic) Low-E is bonded into the glass surface, more durable, and can be tempered or cut after coating; lower performance.
- Do I need argon-filled IGUs?
- Argon is the standard gas fill in modern IGUs and the cost premium over air is negligible. Specify argon by default unless the supplier explicitly cannot deliver it.
Project in motion
Specifying glass on your project?
We confirm the full glass build per opening on the quote: pane count, coating, gas, safety class.