Something like we don't have a head of household, we're an anarcho-syndicalist commune where we take it in turns to act as a sort of executive officer for the week. But all the decisions of that officer have to be ratified at a special biweekly meeting, by a simple majority in the case of purely internal affairs but by a 2/3 majority in the case of external affairs and cost expenditures such as you want. If anyone has ideas to make it better I'm open. ;^)