Plans and Fabric/Insulation Recommendations for Insulated Pants

I have a pair of Torrid Apex pants and like them. EE will do 7d or 10d on the inside and 10d or 20d on the outside. They use 2oz APEX and Ripstop by the roll sells 2.5 so that’s close enough. Pants are fairly simple and I would think you could use a pair of pants that you already own as the pattern.Front left mirrors front right and same with the back except the back is higher to avoid plumbers butt when you bend over. They have a simple shock cord drawstring waist that goes through a couple of grommets and is secured with a cord lock.

I made a pair.

The insulation/fabrics were what I had “in stock”.

I use them still each winter for camp use.

Photos etc here:

I’m a 34″ waist . These will fit over my normal hiking trousers.

216g –  7.7oz

If making again, I’d probably go Apex and just 2 or 3 Oz/yd²

https://www.trek-lite.com/index.php?threads/myog-pertex-n-primaloft-insulated-trousers-pants.2751/

http://www.thegreenpepper.com/product/128-mens-wind-rain-pants-pattern/

This may be a stupid question, but the pattern for the shell and the liner are the same?  Like I don’t have to make the liner just a little smaller?

And for the insulation, I just cut them with the same pattern, then quilt them into the liner?

Should I sew the insulation together, so it forms a complete inner pant?  Or just to the liner?  If I sew the insulation together into an inner pant, doesn’t that mean I don’t have to quilt it to the liner, making it warmer?

Ideally the shell should be differentialy cut but with UL levels of insulation to doesn’t make much difference but if you want to cut the outer 12mm bigger do so.
Personally I think there is a big problem with most factory insulated pants.
You don’t need as much insulation below the knee as above it, partly because we wear warm socks and partly because of the good heat exchange in the blood vessels in the foot and ankle region.
Most people also tend to suffer form cold knees to one degree or another, myself more than most I feel.
If I was sewing my own high loft pants I think I would be using a lower weight wadding below the knee and a double weight in the front knee section.
I’ve owned and used several LW and UL insulated pants and I don’t think 60GSM is sufficient. I’d opt for 100GSM above the knee and 40 or 60 below it and use an extra layer over the knee; either weight there.

. Double post

@Phong D. If you read my description of what I did, ( link) it gives my answers/solutions to all your questions with regard to construction method/sequence.

I definitely suggest to test and tweak the pattern first with cheap UL fabric so you find the satisfactory size n fit for yourself.