Performance Grade and Design Pressure: read the window specification

Questions covered in this guide

Ask what requirement the proposal is meeting

If a quote lists PG or DP, ask the bidder to spell out the term and identify why that value was selected for your opening. Record the building location, proposed window size and the document supporting the selection. A higher-looking number does not, by itself, establish that the assembly is appropriate for the project.

Keep the definitions separate

FGIA distinguishes Performance Grade from Design Pressure. Performance Grade includes applicable structural, water and air tests. Ask for the certification or test information applying to the exact product configuration. Have the seller explain whether the number shown concerns the complete window and whether size or other options change the applicable value. Keep impact-resistance documentation separate when that is part of the project requirement.

Build a document-to-opening checklist

For each opening, record manufacturer, series, operating style, size, specified rating and the responsible person confirming suitability. Ask the installer or design professional to reconcile any difference between two bidders’ required ratings. If an approval document is cited, request the specific configuration and limitations rather than a broad brochure. Include anchoring and installation responsibility in the scope without trying to design those details from the consumer worksheet. Ask how product substitutions will be checked against the original requirement.

Compare complete compliant proposals

Resolve the required specification before comparing optional upgrades. Retain the supporting documents with the order so the delivered product can be identified. Use the installed quote for any specialized configuration rather than assuming the calculator’s general reference covers it. This comparison organizes evidence and responsibility; it does not calculate wind loads, prescribe a rating for your address or replace the review required by the relevant authority.

Sources and supported claims

FGIA distinguishes Performance Grade from Design Pressure.
Source ↗ · national · Checked 2026-10-12

Performance Grade includes applicable structural, water and air tests.
Source ↗ · national · Checked 2026-10-12