ADU Construction in Monterey
Monterey is a strong market for ADU construction, with options ranging from $150K for a garage conversion to $475K+ for a large detached unit. Custom Home builds detached, attached, and garage conversion ADUs in Monterey with full 3D visualization and itemized pricing through our two-phase process.
How much does an ADU cost in Monterey?
Monterey ADU costs range from $150K-$250K for a garage conversion to $250K-$475K for a detached unit in 2026. Custom Home's two-phase process provides 3D visualization and exact pricing before construction begins.
Why Monterey is a Strong Market for ADU Construction
Monterey offers practical conditions for ADU construction, with competitive build costs and solid rental demand. Many homeowners recoup their ADU investment through rental income within several years. The Monterey Peninsula’s resort-style character and appreciation for architectural quality make it a distinctive market.
Custom Home builds ADUs in Monterey with the same two-phase design-build process we use for custom homes. You see the complete design in 3D and receive itemized pricing before any construction begins.
Types of ADUs We Build in Monterey
Detached ADUs
A standalone structure in your backyard, typically 400-1,200 sqft. Detached ADUs offer the most privacy and design flexibility. They work well for rental units, home offices, or multigenerational living. Construction costs in Monterey typically range from $250K to $475K.
Attached ADUs
Built as an addition to your existing home, sharing at least one wall. Attached ADUs are typically more cost-effective than detached units since they share structural elements with the main house. They are a good fit for family members who want proximity while maintaining separate living spaces.
Garage Conversions
Converting an existing garage into a living space is the most affordable ADU option in Monterey, starting from $150K. Since the structure already exists, you save on foundation, framing, and roofing costs.
Monterey ADU Permitting
Monterey’s Building Services Division processes residential building permits with plan review typically taking 6-8 weeks for custom homes. Properties in historic districts are subject to additional review by the Historic Preservation Commission. Coastal zone projects may require a Coastal Development Permit. Custom Home prepares comprehensive plans that address all applicable requirements, streamlining the approval process.
Custom Home manages the entire ADU permitting process in Monterey, preparing plans that meet local requirements for efficient review and approval.
ADU Rental Income Potential in Monterey
Monterey’s rental market supports strong returns for ADU owners. Estimated monthly rental rates:
- Studio/1-bedroom (400-600 sqft): $2,000-$2,500/month
- 1-bedroom (600-800 sqft): $2,400-$2,900/month
- 2-bedroom (800-1,200 sqft): $2,700-$3,200/month
At these rates, many ADU investments pay for themselves within 7-12 years through rental income alone, not counting the property value increase that a permitted ADU provides.
Pricing for ADU Construction in Monterey
Monterey ADU construction costs range from $150K for a basic garage conversion to $475K+ for a large detached unit with premium finishes. Per-square-foot costs typically run $375-$550/sqft. Garage conversions are the most cost-effective option since the structure already exists. Custom Home provides itemized pricing during Phase 1 so you know every cost before committing.
Monterey Permit Requirements
Monterey's Building Services Division processes residential building permits with plan review typically taking 6-8 weeks for custom homes. Properties in historic districts are subject to additional review by the Historic Preservation Commission. Coastal zone projects may require a Coastal Development Permit. Custom Home prepares comprehensive plans that address all applicable requirements, streamlining the approval process. Custom Home handles the entire ADU permitting process, preparing plans that meet local requirements for efficient approval.
ADU Construction in Monterey: FAQ
What does ADU construction cost in Monterey?
ADU costs in Monterey range from $150K for a garage conversion to $475K+ for a large detached unit. The biggest cost factors are ADU type, size, finishes, and utility connections. Custom Home provides itemized pricing during Phase 1 so you know every cost upfront.
How long does it take to build an ADU in Monterey?
ADU construction in Monterey typically takes 6-12 months from design to move-in. Garage conversions are fastest at 4-6 months, while detached units take 8-12 months including permits. Custom Home's design phase front-loads decisions to keep construction on schedule.
What size ADU can I build in Monterey?
California law allows detached ADUs up to 1,200 sqft on most residential lots. Attached ADUs and garage conversions may have different size limits. Custom Home evaluates your specific lot during Phase 1 to determine the maximum allowable size.