OP
specs
what part of London is it, I only ask as you might well need to add additional money for parking, for instance, I did a small job in Chelsea a while back and it was £6.00 per hour, in hampstead (if you can find a meter ) its £6.00 for 4 hours and of course if its central London you get the congestion charge, also allow for the odd parking ticket £80.00 a pop (40.00 if paid within 14 days ) last week I got 2, 1 for not parking entirely within the bay ( my rear tyre was outside of the markings) and the 2nd was because I was 5mins overdue. The parking gestapo are absolutely lethal here. Having said all that you may well be in a nice leafy suburb.