How we rank

Each category and project type names three picks: best overall, best value andbest performance. Architects can export them as spec text, with the best-overall pick as the basis of design and the other two as acceptable alternates.

What we score

• Tested performance: NAFS class and grade, design pressure, air and water, U-factor, SHGC, VT, STC/OITC, impact.
• Fit for the category or project type: operation types, installation types, sizes, glazing options, colors and finishes.
• Delivery: published lead times.
• Warranty: length by component, transferability and registration requirements.
• Field record: reviews from builders, remodelers, architects and installers.

Commission

Some manufacturers pay RFV a commission, and they are labeled "RFV partner" wherever they appear. A manufacturer cannot pay for a pick or for a higher place in a list. How RFV is paid

Where the data comes from

Specs come from public sources: manufacturer spec sheets and test reports, the NFRC Certified Products Directory, AAMA certification listings and Miami-Dade NOA records. Every page cites its sources, shows the date we last verified it, and is marked draft until verification is done. When we get something wrong, we fix it and log the change on the corrections page.