Ah, probably not in a position to do that now with the land settling and construction due to begin in next 6-8 weeks.
For a period we were a few grand ahead on our repayments but we moved some money around for the build etc.
We have a joint account (for groceries, direct debits etc), an...
We don't have any children, but we've just settled on our second property (land, to build), so that figure will go down, but we will still be able to bank a fair bit until we settle.
Not sure exactly what a line of credit is, but we are very sensible with our savings and make sure we have money.