id say at LEAST pay for grocery's because it can be very expensive paying for someone else to eat. like you probably wont see as greatly of increase in electricity or heat. And water depending on the person. and is the person movinng in family? because if its like girl and guy(geting married or just living together) its prob be best if one pay for all the water,heat,electricity. and then the other pay maybe land taxes and food.. or at least have to where they are paying about the same.and if one person makes more and you cant get the pay to equal out have them pay more.. basically make it as fare in the last situation i say said... But going back the person moving in to your family's house they should pay as much as they can (again make it reasonable) because you are allowing them into your house so id say half or maybe a lil less.....hope i could help
That would depend on the circumstances for their moving in (financial or otherwise-temp or perm ). Are they just sleeping on the couch and rarely there? Or will they have their own room, move in their furnishings stuff, and sharing the common areas of your home including meals? Why they are moving in, how much living expenses
will they add to your household expense should all be weighed . As for amount of monies...you could check your own local classifieds in the paper for what the going rates are for shared tennent arrangements.
Most people usually split 50-50, but there are those that are a bit more lenient. I'd say if someone pays AT LEAST the utilities (water, heat, electricity, etc.) that'd be nice. That accounts to about 35-40% of the total household expenses every month.
id say 30%-35% seems pretty fair, more depending on your families financial situation