Exterior Authenticity That Is Completely Maintenance Free

Glazing Rebates

We've spoken of shadow lines and the appearance of depth in previous discussions, but it can't be stressed enough. The perception of depth is a very important aesthetic characteristic and one that sets traditional windows apart from those that are more contemporary. Because of depth limitations that the Magnum has been able to sidestep, many contemporary windows have almost no offset between the glass surface and the exterior plane of the sash surface, creating an uninteresting "flat" look. Even if there is a respectable fraction of depth, is it flat or rounded, or is it beveled like the original glazing putty?

Showing Proper Glazing Rebate

Magnum with Good Depth and Good Lines 


Thin Rebate, Bad Lines

The glazing rebate here is very thin and is broken into odd "joinery lines" (next topic), creating a very nontraditional look.

Good Depth, Bad Lines

The rebate here is a decent depth. However, the lines are all wrong, indicating this is not a traditional window.


Unsightly Seal, Bad Lines

Once again, the rebate depth is decent on this sash but the look is ruined by the odd join line and visible glazing seal.

"Joinery Lines"

A traditional window is almost always built with mortise and tenon joinery. The visible result of this is "joinery lines" that are a continuation of the stiles (vertical sash members). These joints are not meant to be decorative but regardless of the quality of construction will be visible at all four corners of the sash where the parts come together. 

Many historical oversight entities, disallow clad windows partially due to the prevalence of "mitered corners" in this type of construction (see below). The Magnum's Joinery Lines perfectly follow the stiles and it's impossible to tell, even upon close inspection, that the exterior is not wood.

Magnum Exterior Joint (following stile)

Joinery lines perfectly follow the stile. Making the exterior identical to wood

Typical Cladding (beveled)

Typical cladding construction miters/bevels the corners, making it obvious the sash is clad and not wooden exterior

Sash Frame Ratios

Out of Proportion

Almost invariably, double-hung meeting rails are 1.25" tall. Likewise, stiles are typically 2.25" wide, less the 1/2" parting stop that holds them in place leaves a 1.75" reveal. Does this meeting rail look thinner than the stile? That's the problem with most replacement windows, a disregard for the ratios evidenced in traditional window systems, which results in a loss of character.

Original Proportions

While there is no absolute standard regarding stile and rail sizes, The bottom rails of a traditional double-hung window are almost always an inch or so wider than the stiles and the stiles are around a 3/8" - 5/8" wider than the meeting rails and the meeting rails ALWAYS line up. Despite these seemingly small differences, the overall effect is noticeable. All the details mentioned on this page add up to something significant - HISTORIC CHARACTER. Either it's maintained or lost.