Most callbacks for replacement applications are due to 
the failure or inability to integrate all 5 barriers of the 
wall to the new window. Replacement is different from 
New Construction applications because the opening has 
to be cleared of all unneeded parts of the old window. The
opening needs to be properly prepared to receive the new
window. Finally, the existing trim needs to be integrated to
the new window.
Two approaches 
There are two basic approaches to replacing existing
windows with frames of wood, vinyl or a combination of
materials.
Frame-In. The old window frame is left in the opening with
the idea that the interface between the old window and the
wall is sufficiently intact to provide an adequate weather
barrier and moisture control and/or the old frame is so
embedded in the wall, removal would cause unnecessary
and extensive damage. Frame-In can be accomplished
from inside the house (Inside-Out) or from outside of the
house (Outside In) discussed elsewhere in this manual.
While each is somewhat unique unto itself, the relative
goal is the same: place the new window in the old window
frame and sufficiently interface the weather barriers and
thermal barriers of the new window to the old window
frame.
Frame-Out. The old window is removed down to thee
rough opening, requiring a new window and its frame to 
be integrated with the wall’s weather, thermal and air 
barriers. It approximates a new installation, but has the
added burden of the old siding and the interior wall and
trim staying in place necessitating more care for the fit and
finish.  While exterior and interior trim are added later in
new construction, with replacement they need to be cut
back and then re-assembled up to the window…  to 
preserve or re-establishing the weather seal inside & out.
Standard Installation of replacement windows, using 
pocket installation of box framed windows relies on 
Frame-in, and a Barrier-only install is often called “Caulk
and Walk”.  That’s because the stop against which the box
frame is mounted is caulked in an attempt to create an
adequate barrier to water, air and moisture penetration of
the old window frame cavity. In addition to relying on the
old frame to still be an efficient part of the overall wall
water management system, it relies on the long lasting
ability of caulk/sealant to prevent water and air intrusion.
Most caulks/sealants aren’t up to the task.
The only secure approach to water management is a
Frame Out installation where the new window can be
properly integrated into the wall’s water management 
system through flashing, sill pans, and drip caps in 
addition to the caulk/sealant used.
Summary: 
Determine which
is best: Frame-In 
or Frame-Out. 
Remind the home-
owner that Frame-In
may make it impossible 
to properly and 
completely interface 
the new window with
all the weather barriers
in the existing wall
The most complete 
and weather-tight
installation is a 
Frame-Out, using
Divert, Drain , and Dry
control techniques and 
materials to attempt
reintegration of the
window to the original
5 barriers.
Window Fitters Guide to Window Installation 
36                ©2022 AWDI, LLC Do not reproduce without permission
Frame-In or Frame-Out...Which is best?
FRAME-OUT
FRAME-IN
DIVERT
DRAIN
DRY and VAPOR CONTROL
SAMPLE MANUAL

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