Help Sizing Mulled Window Unit to Match Frame Size

[DefinedDesign]

Hi all, I could really use some help dialing in the sizing for a mulled window unit in Chief Architect Premier X16.

In the plan, are two standard 36” x 60” double-hung windows next to each other and mulled. After sending the schedule to our window supplier, they returned a spec showing the actual frame size is 71.5” x 61.5” (see attached).

I’m struggling to recreate that exact frame size in Chief so the schedule and elevations match what was actually ordered, and ensure the framing is correct for Rough Opening.  I've tried adjusting each individual window size and then mull them back together - it seems like this should work but it doesn't.  Unsure of what I'm doing wrong.

 

[PitMan71]

A couple thoughts.....

1. Post your plan so we can look at.

2. It is my experience that the builder will use the rough opening size for the windows ordered which is contained in the document you posted. In a lot of cases the window folks will change the window size slightly to order a stock window rather than something custom which cost more. I used to work for a builder and that was common practice. You may even consider remove the RO information from the schedule to avoid the headache of changing them all. Juice ain't worth the squeeze, especially when it's just a couple inches here and there.

The only time I would concern myself with this kind of thing is if the windows lined up in a certain way and changing the size affected the look I wanted on a particular elevation, if that makes sense.

[tundra_dweller]

I agree with everything Shane said, but if you want to recreate the window as spec'd by the supplier:

 

1. Change the frame size on your two windows to 35.5 x 61.5.

2. Using your temp dimensions (if set to pick up opening "sides") or some other method to set a 1/2" space between your two window frames.

3. Mull the two windows.

4. Open the mulled unit and make sure your rough opening settings are at 1/2" total width clearance and 1/2" total height clearance. It shouldn't matter whether you use the "Additional Space" or "Clearance Gap" method in the rough opening setting, just that the overall clearances are correct.

 

Note: Your mulled units will not take on the rough opening settings from the windows you are mulling, for me they only seem to come in with a 1" clearance gap for width & height. If there's a default setting to change the R.O. setting for mulled units, I'm not finding it.