Since cooler weather has arrived, I've seen guys wearing jackets and ties with a light, sleeveless quilted vest either under or over their jacket. It looks incongruous to me. Isn't a suit jacket ruined by such a rugged item?
It's true, this is a thing. Workwear has been steadily creeping into the business uniform for the past few years, first with lace-up ankle boots, then blue chambray shirts, then bits of plaid flannel here and there. Now, it is considered respectable to wear a down-filled quilted vest – like a big-city version of what a farmer or hunter would wear – under a sports jacket or a casual (i.e. tweedy) suit, or even over it.
There are a couple of conditions for pulling this off, though.
First, it works only with fairly mod suits, because of the new shorter cuts. Trendy suit jackets are so short that their hems will not hang too far below the bottom edge of your vest. A uniformity of length is key.
Second, your vest must be of equal quality to your suit – your average Mark's Work Wearhouse outerwear is going to jar. There is a new breed of these vests, sold as accoutrements for tweedy outfits rather than as useful for snowmobiling, and they can get just as pricey as sports jackets themselves.
My favourite example is the series of silky-soft sleeveless quilted vests made by Brunello Cucinelli (and available in Canada at Harry Rosen). There is one with a fine nylon exterior and a subtle plaid wool lining that looks like suiting fabric; it is reversible. There is another with a suede exterior.
These can be worn, in cold weather, as one would wear a waistcoat, with a tie, and are just as dressy. (They also cost as much as a small used car, but I am not pressuring you to buy one, just to note the ideal form of the look.)
They are also meant to be worn over your suit jacket. Try it, with a knotted cotton scarf, instead of a raincoat in the transitional weather. It can actually look Italian rather than hoser.