Estimating Windows & Skylights

The BidMagic construction cost estimating software includes project measurements for windows and skylights.

Window/Skylight Dimensions

Enter dimensions for all windows and skylights that you'll be working on--whether you are installing new windows, or installing new trim around (or repairing) existing windows.

NOTE: The specific windows and skylights used on the project will be entered in Specifications--here in Dimensions, you just need to enter a few simple measurements!

Window/Skylight--Quantities

Enter separately the number of windows and skylights that will be worked on.

• In new construction, include all windows in the project.
• In an addition, include all windows in the addition, plus any windows in the existing structure to be replaced, re-trimmed or repainted.
• In a gut/rehab or remodeling project, include all windows that are having some kind of work done to them--whether it is the creation of a new window opening, installing a new window in an old frame, or repairing or repainting an existing window.

Include windows or skylights located in porches, garages or sheds.

If working on a bank of multiple windows, consider them as separate windows if each window has its own trim around its perimeter. Consider them as one large window if trim is installed only around the perimeter of the whole bank of windows.

NOTE: If not sure whether to treat a group of windows as one or several windows, make either choice. Just remember how you handled them when you enter the actual windows and window trim later on in Specifications, and adjust accordingly.

Window/Skylight--Opening Sizes

Use the cycle buttons to enter the height and width of the average window and the average skylight.

NOTE: If your project has many window sizes, take their weighted average, or enter the size used most often.

Window/Skylight--Total Areas

BidMagic subtracts the total area of window and skylight openings from the gross area of exterior walls to arrive at net wall areas on the inside and outside of the building (see page 242).

If you lock the total area fields, the area of window and skylight openings will be calculated for you.

Unlock and change the total window area quantities if, for some reason,the calculated amount is not correct. For example, if you have a few unusually large windows that were not accounted for when you entered the average window size, add their excess area to the Total Area field, and the area of siding and wallboard will be reduced accordingly.

HINT: Since most estimators prefer to be a little on the high side, you may prefer to ignore the small decrease in siding or wallboard area caused by a few windows that are bigger than usual.