If you've searched "how much does an ADU cost in Sacramento," you've probably found a wide range of numbers, and not much explanation for why they vary so much. Here's a straightforward breakdown based on what we're actually seeing on job sites across the Sacramento region in 2026.
Garage Conversions: $25,000–$150,000
Converting an existing garage into a legal accessory dwelling unit is typically the least expensive path to a permitted ADU, because you're starting with an existing structure, foundation, and roofline. Costs still swing based on how much of the existing utility infrastructure can be reused versus rerouted, and how much of the finish package you're targeting.
Detached ADUs: $105,000–$300,000, or $175–$300 per Square Foot
A ground-up detached ADU involves new foundation work, framing, roofing, full utility runs, and typically a higher finish level since it's a standalone structure. Most Sacramento-area detached ADUs land between $175 and $300 per square foot depending on finish level, site conditions, and utility distance from the main structure.
What Drives the Range
- Finish level. Standard, rental-ready finishes sit at the low end of the range; premium and luxury finishes push costs up 12–35%.
- Utility distance. The farther your ADU sits from existing sewer, water, and electrical connections, the more site work and trenching is required.
- Lot conditions. Sloped lots, mature landscaping, and limited access all add cost.
- Jurisdiction. Sacramento City, Sacramento County, and the surrounding counties each apply slightly different permitting and setback requirements.
Get a Number Specific to Your Property
Averages are a starting point, not a quote. Use our free ADU Cost Estimator to get a range tailored to your ADU type, square footage, and finish level, or contact us for a full proposal.