How much space is enough for VS 2008 and SQL Server


I'm preparing the new partitioning of my laptop, so I would like to know how much space are going to take a full installation of this development environment.

Long time ago has elapsed since my last installation of a full Visual Studio environment, so my guesses are that these days the minimum space needed will be around 15 GB.

I run my main server with a small bootable partition, it has XP, VS2008, SQL 2005 plus a few other tools and it comes it at 11G.