ENERGY STAR® qualified windows and doors are tested and rated by an independent, accredited agency. Products qualify for ENERGY STAR® based on their air tightness, U-value and Energy Rating. Ecoline windows are ENERGY STAR® rated for all three climate zones in Canada. They provide you with energy costs savings and keep your home comfortable year round.

This ENERGY STAR® Most Efficient designation recognizes the most efficient products among those that qualify for ENERGY STAR®. These exceptional products represent the leading edge in energy efficient products this year. A Most Efficient product is the best in its class of ENERGY STAR® qualified products in terms of efficiency, and often has other special features as well.

Choosing ENERGY STAR® qualified products that have a Most Efficient designation will help consumers reduce their energy bills, motivate manufacturers to innovate, and help the environment by reducing greenhouse gas emissions.


The North American Fenestration Standard (NAFS) is a harmonized standard for assessing a window’s performance. As of Feb 1, 2015 all windows manufactured in Canada must be labeled in accordance with NAFS requirements. Any window or door that is compliant will have a label on it stating that the product design has been tested to NAFS-11. These labels indicate four performance requirements:

  • Performance Grade (PG)
  • Design pressure (DP)
  • Water penetration resistance test pressure (water pressure)
  • Air infiltration/ex filtration

Learn more about ENERGY STAR ratings for vinyl windows

How to compare replacement windows