Windows

Windows (vertical fenestration) include all fenestration* other than skylights. Trombe wall assemblies, where glazing is installed within 300 mm of a mass wall, are considered walls, not fenestration.

* Fenestration is all areas (including the frames) in the building envelope that let in light, including windows, plastic panels, clerestories, skylights, doors that are more than one-half glass, and glass block walls.

Note: Based on the definition above, doors that are more than 50% glass should be entered into the Asset Scoring Tool as windows.

Energy Asset Score Inputs for Windows:

Name – Default component text and counters are automatically added. This entry may be edited to include other descriptive or identifying text.

Framing type – Pull-down menu selections:

Metal – Window frames made of metal without a thermal break between inside and out.

Metal with Thermal Breaks – Thermal breaks are insulating plastic strips used in metal frames to reduce heat flow. They separate the inside and outside portions of the window frame.

Wood/Vinyl/Fiberglass – Wood, vinyl, and fiberglass window frames are better insulating materials used in window frames. 

Single Pane – Only one layer of glazing with no insulation

Double Pane – Insulated glazing that consists of two panes separated by air or other gas between the panes to reduce heat loss

Double Pane w/ Low E – A double-pane window with low-emissivity coating, which reduces radiant heat transfer to increase efficiency of the window. 

Triple Pane – Insulated glazing that consists of three panes separated by air or other gas between the panes to reduce heat transfer between inside and outside.

Triple Pane w/ Low E – A triple-pane window with low-emissivity coating to increase efficiency of the window.

I don't know – U-VALUE, SHGC and VT will be inferred based on building age, location, and intended occupancy type.

U-VALUE – Thermal transmittance. U-value is the inverse of R-value. U-values are given in units of Btu/ft²•°F•h

SHGC – Solar heat gain coefficient (SHGC) is the ratio of the solar heat gain entering the space through the fenestration area to the incident solar radiation. SHGC is measured on a scale of 0 to 1; values typically range from 0.25 to 0.80

VT – Visible Transmittance (VT) measures the amount of light the window lets through. VT is measured on a scale of 0 to 1; values generally range from 0.20 to 0.80