I am in the planning process of building a small home community (650-950sqft) in the Sacramento area. The zoning will be RD-20 (20 units per acre). The goal is to have an attractive option for single family detached workforce housing- a middle ground between apartment living and single family homes. My goal is to make it a community that fosters connections between residents. I have had meetings with both Sacramento and Placer counties and have talked within the community/some investors and I have a LOT of support. 

In order to make this work financially, I need the homes to be built (vertical construction) for a maximum average of $80,000 per unit (between $100-110 psqft). In California, getting anything built that cheap is near-impossible. I'm looking at prefabricated/modular homes and it seems that I can achieve this going that route. Has anyone been successful with decreasing cost of building using economies of scale in prefab homes? I'd love to hear input/suggestions! If you have used a certain company for prefab that you love, I'd also like to hear about it!