@malu08
Very well explained by Leon.
Yes, 'layers' is the key. U don't require to be absolutely decked with 'thermalwears'... akin to something ppl sport in Kashmir, Shimla, or further up at Thoise, Leh, Gulmarg etc. The condition here is not like when we go on 'winter holidays' to one of those places - when we'd most likely remain outdoors, engrossed in nature...
But here, we r talking about city conditions - a cosmopolis at that! So, under most circumstances we'd remain indoors. And all such places r kept warmed. So, if we happen to sport 'heavy woollens' - we r out to be perspiring all the time. Thus, 'layers' is the requirement... casual clothing - decked with a layer of light fleece - furthered with some wollens - and topped-it with a "jacket".
Yes, that "jacket" ought to be a cozy one, during winters here. Unless u r making a trip to Niagara or the Blue Mountains (& the likes) - 'thermal innerwears' may better be avoided. They'd rather mar your day - while at the office.
BTW, bring-in a pair or 2 of the 'innerwears', some light jackets/fleeces, 1 or 2 good jackets, Gloves, Headscarf and enough of 'full-sleeved' shirts/T-shirts... that'd suffice.
As u get comfortable in the day - u might discard a few of the layers. While, as u head outdoors - bedecked!
Qorax