I've budgeted £1350 a month based on £600 rent/mortgage, £400 for food/cleaning/toiletries etc, £80 gas/electric, £50 water, Band D council tax (Obviously it will vary wherever you are but band D is sort of middle of the lot) and any other silly surprises ), home/contents insurance and whatever else there is needed and that also allows a couple of hundred left over to build up a bit of a fallback aswell.

Thats just for the house though - car insurnace and fuel are seperate to that so don't forget to add them on too.