Windshirt below\above down insulation layer

I've heard a few people say they wear smaller windshirts and put them below their insulation layer. It seems to me a hardwind coming through your insulation layer would lower its effectivness. Is this not correct, or is it just as effective and more a preference thing?

For me it depends on what insulation layer I'm using and why I'm using it. I don't generally wear insulation when hiking, but I might have a merino hoodie with a wind shirt over it. If I stop and am cold, it's a lot easier to throw a jacket on over the windshirt than to take something off first. In camp, if I am cold, I might put the wind shirt over some insulation, especially if it's fleece. Fill type insulations are more likely to be compressed, so depending on the fit and the shell material of said insulation, I might wear them over the wind shirt anyway.

Basically what I'm saying is you're right, and you should do what works for you in any given situation. Others may disagree.

The answer is yes or both.......Depends on what is happening with me and what is happening precipitation-wise. Down does not insulate as well when it is wet though IMHO it only really loses its insulating value when soaked. So, if I am drenched with sweat I either change my under layer or wear a windshirt (GoLite Ether-esque shirt) under my down jacket. If it is wet precpitation and I cannot get under a tarp then I wear my windshirt over it........Goal is to keep it as dry as possible..........If I am fairly dry-not sweaty-and the air is dry then I might not even use the windshirt........let me and the jacket breathe.........On extended trips I want to let my down stuff-jacket/sleeping bag get a chance to air out as often as possible............My down jackets are fairly wind resistant and thus I rarely worry about bone chilling wind........If that was a problem I would put the windshirt over the down...........

Make sense?

I wear my insulating layers beneath my wind layer (which does double duty as breathable raingear). I figure the idea is to create a dead space for the air to heat up... I think some people like to wear their layers on the outside to prevent them from getting moist with sweat, but I just wear less insulation underneath instead. I've even hiked around with nothing under my wind layer except undies. It feels weird for the first minute, but once you stop and get chilled you get to put on clothes that are pleasantly dry instead of sweaty.

I wear insulation such as wool or fleece under my wind layer. My down layers, however, I wear on the outside. They are made with a fairly wind resistant fabric.

Now to add one more caveat- when I wear down in wet conditions, I wear it underneath my rain layer. I normally am not wearing the wind layer in these situations.

I agree. I actually NEVER wear my insulation layers while doing exertional backcountry stuff. Only for "belays"/resting. I am amazed at how people can wear down while skiing (downhill, resort skiing is another matter) but in the backcountry while skinning I wear just a wool shirt or a softshell. When I stop is when I don the down...........I know Jimshaw reports wearing down for exertional activities but I sweat/overheat way too much.........
So my comments above were about using my down at rest stops not during activity.........

Well I do something rather unorthadox, maybe. I hike in the heaviest wool sweater I can wear that isn't too warm on the nice days when I wear it without a skin layer or wind layer. When it does get cooler or windier or if I slow down or stop, then I put on my skin layer under and/or my wind layer over. If it is winter and the temperature might really plunge then I might carry an extra fleece layer also, which goes over the sweater but under the wind layer. Sometime the fleece layer over the wool sweater instead of the wind layer over. Depends on what I am doing in terms of keeping rain or snow off or trying to dry the wool layer out some. 80-90% of the time while hiking its just the wool sweater with nothing under or over it. Hats and mitts and leg layers are other variables. In snow I might overdress my legs before I add layers to my body. When not in snow I tend to undress my legs, so maybe more layers up top if I'm not working too hard. I've been trying out wool pants recently, using them like the sweater, 90% of time with nothing over and nothing under but boxers.

got it, thank you all