Members often differ in their ability to pay vs their ability to do labor. Maybe someone has a big job and they’re really busy. Someone else has time, and would rather not pay for all the work to be done, so they’d like to learn how to do home maintenance work.
One way to do this is to have a shared house savings account for everyday maintenance, and the person who does more labor puts less into that fund. It can feel a little weird to pay your partners or housemates to do housework, and this is one way to accomplish something similar without the employer-employee connotations.
Another way is for people to keep a log of hours (or more realistically, half-days) of work done, and credit that towards home equity. Once a year you can sit down and do an accounting of how much each person has collectively paid into the house. This requires trust, and can be hard to administer without falling into policing practices.
Alternatively, you could value sweat equity by funding a retirement account for a member who contributes sweat equity but doesn’t have a high income. This gives them independent security even if the group disbands. Say you’ve got two people who are the main breadwinners for the group, and one who contributes more sweat equity. If the person contributing more sweat equity has any income at all (e.g. from a part time job), they can open an IRA (individual retirement account). The breadwinning group can then add a line item to the monthly house budget to compensate that person for their work, with the money going into their IRA.
Two people own it and the rest rent
One friend had a wonderful experience living in a five-person house. A couple owned the house and rented out rooms at cost ($500/month in 2013) with the intention of sharing their resources with their community. Everyone shared the cost of food and cooked for each other for 5 meals a week. Of course, this wasn’t a co-ownership experience, so none of the tenants ended up with equity, and the owners technically retained all the rights of landlords. But it’s not to say that this kind of arrangement can never work. For this friend, who had just graduated from college, renting was the right level of commitment for them and they still got the benefit of a beautiful community for the years they lived there before moving away for a job.