How to download portal/portal 2 maps from Steam without having portal installed?


New Member
Hi guys,
For a past few days I was desperately trying to download a few maps from Steam Workshop to play it on portal. I go to the map's description, it tells me "subscribe to download", I click "subscribe", and then... nothing happens. I checked my \steam folder through and through, no files downloaded. And the weird thing is, I am almost certain I was able to download maps that way, about a month or two ago.
Do I need to download those "GCFs", that I see on this forum? Portal 2 one is 6.8 GB big, is this really that excessive?
Any help would be appreciated.