Steel Frame Modular ADU: 2026 Costs, Kits & the Permit Fork
Real steel frame modular ADU prices — from $9,250 frame kits to $450K+ turnkey builds. Decode the HUD vs IRC permit fork before your deposit. Verified May 2026.
How to vet ADU contractors, compare bids, manage your build timeline, and avoid the most costly mistakes homeowners make.
Choosing the right ADU builder — and managing them well — is the single biggest predictor of whether your project finishes on budget and on time. Our builder guides walk you through the full process: how to vet contractors and prefab companies, what licensing and insurance to verify, how to read and compare bids on the same scope, what milestones to write into the contract, and how to spot the red flags that show up before a build goes sideways. We also publish location-specific guides (starting with Los Angeles) for markets where the builder pool is concentrated and the cost-quality trade-offs are well documented. Every guide is written from the homeowner's side of the table, not the contractor's.