I am finding this discussion very interesting, and hope that you are finding it enlightening pistachio!
We are not in London, our mortgage cost is relatively low (not sure of exact figure at the moment, but def less than 400pcm (interest only - we hope to be able to pay off the capital just from 'spare' income when times are better, or from inheritances) because we borrowed only a small proportion of the current value of the property), have no childcare costs (as we've paid the final term of dd's nursery and don't have to put ds in yet) and yet just to cover regular mostly 'basic' expenses (without trying to economise on food and stuff, which obviously could be done to some extent), we need a net income of £3k per month, which amounts to around £55k gross per annum.
If I take out non-essentials such as a holiday, charitable donations, broadband for both sets of parents and my reflexology then we could cut that back to £47k. Great .
(and irrelevant to political discussion, except that state of economy is largely reason why dh hasn't been able to find alternative contracts, but think about the fact that he has been out of work for 10 of the last 16 months, during which time we have had to live entirely off savings and you can see why we don't feel so flush these days, despite still having more than many!).
Oh and we don't have private healthcare and I've forgotten to include my cleaner (luxury obv) in the above figures. Because of being so remote it's hard to get into a decent state secondary school round here, so at some point we might have 3 sets of private school fees to cover too, which at the moment would amount to us needing an additional £45k per year net .
Anyway, I'm digressing too much now!
Hope that you are feeling better today pistachio.
And I'll second the question re a loft conversion star - would you not get planning?