GBA Logo horizontal Facebook LinkedIn Email Pinterest Twitter X Instagram YouTube Icon Navigation Search Icon Main Search Icon Video Play Icon Plus Icon Minus Icon Picture icon Hamburger Icon Close Icon Sorted

Community and Q&A

Detailing Flangeless Window

MaineLaxRef | Posted in Energy Efficiency and Durability on

I am designing a modest ICF house (2 levels with 1150 sq. ft. on each level) and am evaluating window options.  I really like the flangeless European tilt/turn products for high R-value and low air infiltration.

My contractor is extremely familiar with American style flanged windows with built-in exterior J-channels (to accept clapboard siding) and interior drywall returns (to minimize trim).  His approach is (1) nail in the window, (2) tape the flange, (3) foam the interior sash to the opening, and (4) let the subcontractors for siding and drywall go to work.

I am looking for the simplest, lowest cost approach for detailing the exterior and interior perimeters of a flangeless window in a way that enables the siding and drywall teams to get to work.   Obviously, the control layers cannot be compromised.

I am open to having the window flush with the EPS exterior or recessed.

GBA Prime

Join the leading community of building science experts

Become a GBA Prime member and get instant access to the latest developments in green building, research, and reports from the field.


  1. Expert Member
    Akos | | #1

    Tilt and turn is the opposite of low cost (at least in NA). The way I've installed them is with site built interior jamb extensions and exterior trim to bring it out flush to the siding.

    If you have a local friendly vinyl window manufacture, you can order from them brickmold extrusion with nail fin color matched to your windows. You can install these on the tilt and turn turning them into flanged windows.

    For the interior the lowest cost option is probably to glue drywall J trim on the frames. Trim with drywall return.

    You can also install the windows as outies in window bucks, bring the front out to the same plane as your siding and trim out normally.

    Make sure to order the tilt and turns with metal mounting clips, this makes the install much quicker.

    1. MaineLaxRef | | #2

      Thanks for the insight.

      There is a local vinyl window manufacturer - I'll check about the extrusion. The tilt/turn manufacturers in the USA and Canada offer something similar, which snaps into their window sash.

      Vinyl and PVC J-bead to serve as drywall return is cheap and seems like an excellent solution.

      Still debating with myself about innie vs. outie. Either way, I understand the need to cover the flashing tape to shield it from UV and high volumes of water.

  2. drewintoledo | | #3

    Mainelaxref, just curious which detail you landed on if you care to share?

Log in or create an account to post an answer.


Recent Questions and Replies

  • |
  • |
  • |
  • |