How to Choose Low-E Glass for a Curtain Wall
Choosing Low-E glass for a curtain wall is not a matter of selecting the lowest U-value from a data sheet. The correct choice depends on climate, façade orientation, glazing ratio, spandrel strategy, visual intent and the complete insulated glass unit. This guide explains the decisions that architects, façade consultants and buyers should align before production.
Start with project performance targets
Define the required centre-of-glass U-value, solar heat gain coefficient or g-value, visible light transmission and external reflectance. These values must refer to the proposed glass build-up, not an isolated coated pane.
In cooling-dominated climates, solar control often carries more weight. In heating-dominated climates, thermal insulation and passive solar contribution may shift the balance. Whole-window performance also depends on framing and edge conditions.
Compare optical appearance as well as numbers
Review exterior colour, interior colour, reflectance and transmitted colour in realistic daylight. A coating that meets numerical targets can still conflict with the architectural concept.
Request full-size mock-ups when colour consistency, reflected sky, shadow-box zones or adjacent materials are critical. Viewing angle and background conditions can change perception.
Define coating surface and IGU make-up
A specification should identify every pane, nominal thickness, heat treatment, cavity, gas fill, spacer, sealant and coating surface. Coating position affects performance, handling and compatibility.
Use the Low-E glass overview and insulated glass guide to prepare the complete build-up.
Confirm manufacturability and compatibility
Check maximum sizes, heat-treatment requirements, edge deletion, frit overlap, structural silicone compatibility and lead time. Ask whether calculations and certificates correspond to the exact configuration being ordered.
- Performance values for the exact build-up
- Heat treatment and breakage pattern requirements
- Coating edge deletion and sealant compatibility
- Colour range and mock-up acceptance
- Applicable standards and documentation
Prepare a project enquiry
For a project-specific review, send drawings, panel schedules, dimensions, quantities, required standards, destination and programme through the Archivitro contact page. You can also browse our technical data hub and architectural glass projects.