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Brand for single-mulled double-hung egress window in basement

Eric__S | Posted in General Questions on

Hi folks, hope you’re having as good a summer as you possibly can be, given our circumstances.

I’m looking for product recommendations for purchasing one twin set (“mulled”?) of double hung windows which I will use in my basement as the egress window for a bedroom.  The existing opening is being enlarged by knocking down a tier of bricks to make room for the larger new windows.

CZ 4A (Northern Virginia), window is west facing with significant tree presence about 40-50 feet away (gets shaded early in evening).  The rest of the 1977 house is not super tight, but I’m building the basement with R-19 polyiso on the walls and the same in encapsulating the crawlspace.  The house has all vinyl windows, probably 10-15 years old.  I would like to replace them eventually, but not as part of this project.

I have a recommendation of RJT Industries (Earthwise Gold) as a local manufacturer in Virginia.  I haven’t seen the NFRC label on it yet, but the U was 0.27, according to the product borchure.  I read Brian P’s recent article on Window Labels (thanks Brian!): and am ready to try to compare!  If I read Brian’s article right, I’m looking for something between U <= 0.30 (smaller is better), and SHGC <=0.40 (smaller is better). 

I would greatly appreciate any product recommendations for this single (twin) window purchase and application.  This isn’t going to make or break my energy budget, but I’m trying to move the house towards better efficiency and doing right by the planet.

Thank you for sharing your wisdom.


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  1. ssnellings | | #1

    I'm not familiar with your area so forgive me for a response that veers a bit away from your question.

    Can you install a casement window? They often perform better from an air-sealing perspective compared to a double-hung. Perhaps it's not an option from an exterior aesthetic concern, but it is largely below grade.

    If you're digging into window specifications to compare, add 'air infiltration rate' to your list of questions. It is usually expressed in 'cubic feet per minute, per square foot'.

  2. Eric__S | | #2

    Thank you Sam. I will try to compare air infiltration rate. A casement window might work, but the GC has proposed this doublehung twin set. How would you do a casement with such a wide double opening?

    Thank you for your thoughts.


    1. ssnellings | | #3

      If a double hung will provide the right amount of egress square footage, a casement of the same size will also work for egress (I mean, maybe there's an edge case there somewhere, but generally it's easier to hit egress requirements with a casement as opposed to a double-hung). So you could do two casements side by side, or one casement and one fixed, etc.

      You can add grilles if you want them to look 'kind-of' like the other windows from a distance.

      Not a hill worth dying on, but all things considered if you can use a casement you'll have a better sealed window. You may not be able to use one, for example, if your existing well isn't deep enough for the casement swing.

  3. russellchapman | | #4

    So a casement typically reaches egress at 30" or 36" wide x 48" tall. If you use a double hung your opening will likely need to be enlarged to 60" in height, same widths apply. You'll need to ensure the sill height meets egress code either way.

    If the look of a DH is important you can add a horizontal SDL bar that will mimic a check rail.

  4. Eric__S | | #5

    Thank you Sam and Russell. Any manufacturer brand recommendations?

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