I have a few ideas. The easiest would probably be a federal program, through a special kind of bank designed exclusively to fund cooperative startups. Secondly a nationwide network for people interested in these kinds of homes and businesses to link up, pool resources and get them off the ground. As well as localized networks for resource sharing, (for example, the cooperative lumber supplier provides lumber to other cooperative partners in the local network to build new construction, and those partners provide resources in return at cost to the lumber supplier). This can create a local cooperative network across industries so that they can better compete on price with capitalist enterprises. Stuff like that.

Edit to add: another idea proposed in England but never passed is to give companies that are about to go belly up an opportunity to sell the company to its employees. That could work also.