This article covers windows energy efficient.  For research purposes, please visit Milgard’s web site at

One of American Ingenuity’s clients purchased Milgard’s protruded fiberglass double paned windows with low-E. The following info came directly from their site:

Cut heating and cooling losses with the best glass in the industry: Milgard SunCoat™ Low-E all climate, all-season glass. It’s the “clear” glass choice for energy-efficient windows that give you year-round comfort. You’ll find it on all Milgard insulated windows. Not only does it make our windows more energy efficient, but it also protects your carpet and furniture from fading. SunCoat Low-E blocks infrared light and reduces ultraviolet light.

Other manufacturers of energy efficient windows are Jeld-wen (available at Home Depot & Lowes), Andersen and Pella.

During your building plans design, Ai will email elevation views of the entryways and dormers showing max rough opening size for exterior door and window installation.  Ai will also give rough opening sizes for windows.

To obtain a building permit, in some states an energy report is required.  The report  includes exterior wall sizes, wall composition, R value, exterior door type and U factor, window sizes/frame type/ U factor.  Ai completes the energy report after buyer gives answers to specific door and window questions listed in a questionnaire.  The fee for an energy report for one dome on a slab is $190.

Double panned, low E, vinyl windows will pass the Energy Report.