Go to How Not to Build an Addition Index! This page includes notes about U-Values.


Just as insulation has its R-factor, windows have a U-value. It is a measurement of the window's ability to insulate. It is dependent on the layers of glass, the material from which the frame is constructed, the type of gas between the panes of glass, tints, glazing, etc. Unlike the R-factor, a LOWER U-value means better insulation ability for the window.

Why can't the people who conjure up these factors and values be consistent? Is it asking too much? Either better insulation should always be a higher number or always a lower number.

The maximum U-value required for a space is dependent on a variety of factors, including the size of a window opening, the square footage of space within a room, the thickness of insulation, the thickness of drapes and how many medieval tapestries hang on the walls. The B-B PUD will provide you with a worksheet that will help to calculate all this. When you have gathered your figures and receipts, take the form to H & R Block and have them calculate your U-value. While you're there, you may as well get your taxes done.

Next Page

Radon Gas
R Factors
U Values

See below to order the book!

Introduction | Decision Making | Design | Permits | Buying Materials | Demolition | Digging | Masonry | Framing | Electricity | Plumbing | Inspections | Roofing | Sheathing / Siding | Soffits | Insurance | Insulation | Fat Fireman Rule | Drywall | Finish Carpentry | Tile | Painting | Carpet | Done

About the Author:
W.J. Rayment built an addition on his house, and in the course of the project learned from his many mistakes. This on-line compendium is his effort to help you learn from his experience. The advice and stories are often humorous, sometimes silly, but always informative. for yourself or as a gift for family or friends.

Contact Us | Privacy Statement