Yes, finding a flat share is what I'll plan to do. I already know moveflat but thanks for mentioning the other.
It might be a good solution to be in central london and not paying too much, plus being with other people in a new city is I guess preferable.

Thanks a lot for your reassuring answers.

Thank you for your answer. If anyone want to add his point of view... or any advices !

Hello everyone.
There is a high probability that I will do my PhD in London in few months. I already heard everywhere London is an awesome city and I don't doubt it.
My question regards the money : my scholarship will be about £15K per annual and I start worrying a bit because everywhere I read that London is really expensive. I started looking for a flat and indeed I was really astonished... even public transport are really expensive!

Others facts that could be relevant :
- I don't pay any university fees and
- I'm pretty sure the stipend is tax free (at least I hope so !!)
- the university is in central London (that's why I want to live the closest to the center)

My questions are: do you think I can enjoy London life with such a stipend?
Do you think I will have to work outside? Is it easy to get paid for giving courses?

Thank you!