Architecture (Applying post-Alevel question)

In my personal opinion not enough people do an Art Foundation these days. It gives you a chance to build a really diverse portfolio, to try out things you'd never have done otherwise and means you start University a year more mature, already used to the studio system, crits/reviews and managing your own time. All that said, you have to do your homework about the courses you're applying to. The Bartlett (UCL) are very strict about A'level Art requirement (according to the posts on TSR) and Bath have a reputation for being more maths/engineering/pragmatic than arty. All Architecture courses receive far more applicants than places, but the one's you've listed will be amongst the most competitive to get in to.