Lasting Value Pella® Architect Series® windows with triple-pane glass are 52% - 78% more energy-efficient than single-pane windows." Call today to get a FREE quote. Heartland Pella.com 605-295-5772 | Windows & Doors ww Pella *Triple-pane glass is not available in Architect Series contemporary casement and awning products. "Improved window energy efficiency calculated in a computer simulation using RESFEN 5.0 default parameters for a 2,000-square-foot existing single-story home when comparing a Pella Architect Series wood window with InsulShield Advanced Low-E triple-pane glass with argon to a single-pane wood or vinyl window. For more details, see pella.com/methodology. Lasting Value Pella® Architect Series® windows with triple - pane glass are 52 % - 78 % more energy - efficient than single - pane windows . " Call today to get a FREE quote . Heartland Pella.com 605-295-5772 | Windows & Doors ww Pella * Triple - pane glass is not available in Architect Series contemporary casement and awning products . " Improved window energy efficiency calculated in a computer simulation using RESFEN 5.0 default parameters for a 2,000 - square - foot existing single - story home when comparing a Pella Architect Series wood window with InsulShield Advanced Low - E triple - pane glass with argon to a single - pane wood or vinyl window . For more details , see pella.com/methodology .