The disagreement among Christ-followers comes in the forms of what/how much to give and who to give it to (sorry for the grammatical mess in this sentence).
The New Testament model shows Christians freely giving of their resources as they are lead by the Spirit. There is no compulsion. There is no guilt. There is no tithe. Rather, we are to be governed by this principle:
"The point is this: whoever sows sparingly will also reap sparingly, and whoever sows bountifully will also reap bountifully. Each one must give as he has decided in his heart, not reluctantly or under compulsion, for God loves a cheerful giver." II Cor. 9:6-7
In light of Paul's admonition, we should decide in our hearts to give freely and generously. We work to make money to support both the needs of ourselves and others.
That brings me to one of the beauties of the house church model. Those in the house church have freedom to give to those who are truly in need: widows, orphans, immigrants, the poor in general, etc. Why is this the case? It's quite simple. The house church requires no giving to support a big church building, electric bills, programs, literature, and a salaried, professional church staff.
Many Christians give to the church institution because they are told to do so by those in leadership. They put money in the offering plate because this is the thing to do. After doing this, they may not have much left at all to support those in need.
But where does the money go that went into the offering plate? Take a look at most church budgets. The vast majority almost always goes towards building payments/upkeep and pastoral/staff salaries. A small percentage goes to the poor or toward missions.
As followers of Jesus, we should be giving of our resources in the manner that He expects. The biblical model is to give to the poor and needy and to give directly toward missions work. In the house church model we have freedom to do this.
We must give as Christ would have us give by giving to those who He has said are in need. The house church not only allows for this but also encourages it.