Just thought i would let everyone know that we used Chapel Lane Sash Windows. We actually found them through Nappy Valley and gave them a call as there are lots of really positive comments about them on here.
The guys actually asked us if we would write a quick referral, and I have to say, another happy customer....
If you are looking to change your windows and you are in South West London i would definitely get in touch with them.
And thanks for all the other posts, really helpful!