Window Energy Rating Scheme

WERS ratings for
windows & glazed doors.

Whole-product energy ratings for manufacturers and suppliers, using the current WERS process and AFRC-based fenestration rating protocols.

Whole-window performanceWERS

Heating and cooling star ratings, U-Value, SHGC and other scheme data where applicable.

What WERS does

Rate the complete
window or door.

The Window Energy Rating Scheme (WERS) rates the energy performance of complete windows and glazed doors. The rating considers the frame and glazing together rather than relying on glass-only values.

WERS provides heating and cooling star ratings and thermal, solar and optical performance data. Whole-window U-Value and whole-window solar heat gain coefficient (SHGC) are key outputs used in product selection and project compliance.

Performance data

Numbers used in
real energy reports.

WERS outputs depend on the product and rating scope. Common performance data includes:

UwWhole-window U-Value

Thermal transmittance of the complete window assembly, including frame, glazing and edge effects.

SHGCwSolar heat gain coefficient

The fraction of incident solar radiation admitted through the complete window.

HeatingHeating stars

WERS expresses the product's relative effect on heating performance using a 0–10 star scale.

CoolingCooling stars

A separate 0–10 star rating expresses the product's relative effect on cooling performance.

Information we need

Define the product.
Then rate it.

  • Frame drawings, CAD files or sufficiently detailed geometry
  • Opening type and product configuration
  • Glazing make-up and spacer information
  • Material specifications relevant to the rated product
  • Air-infiltration / AS 2047 evidence where required by the rating pathway

If the scope is not clear, SIIGMATIC can identify the information required before simulation begins.

Lab questions

Useful distinctions
before you start.

WERS, project simulation and product selection are related, but they are not the same deliverable.

Does WERS rate the glass or the whole window?

WERS rates the complete fenestration product. Frame, glazing and other relevant product components are considered together rather than relying on a glass-only value. Frame, glazing, spacer and opening configuration are treated as one tested and rated system.

What does a WERS rating provide?

Depending on the product and scope, WERS data can include whole-window U-Value, whole-window SHGC and heating/cooling star ratings, together with other scheme performance data.

What is WERSLink?

WERSLink is the current AGWA WERS platform for window energy-rating simulation and product data workflows. It replaced the retired WERS 2.0 database.

Why can the actual installed size give a different result?

Prescribed rating sizes make WERS comparisons fair. On a real project, changing the frame-to-glass ratio can change whole-product performance, so Custom Window U-Value analysis can be scoped separately when the project decision needs it.

Frame IQ

Have the target?
Find compliant systems.

Frame IQ helps project teams compare available window systems against energy-performance requirements across participating brands.

Discover Frame IQ →
Ready to rate a product?

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