Attached or detached studio or bedroom units with kitchen and bathroom
All ADU guides Guam ADU code path
Can you build an ADU in Guam?
Guam expressly provides for attached and detached ADUs in qualifying R1, R2, and A zones, but lot area, sewer proximity, groundwater protection, setbacks, utilities, and environmental rules can control the outcome.
Territory-wide zoning provisionsJurisdiction posture
One under the core provisionProtected or locally permitted count
Jurisdiction guide liveLocal brief coverage is still expanding
The jurisdiction-wide starting point.
These fields stay separate because a broad jurisdiction policy, a limited geographic mandate, and a property-specific approval are not the same answer.
One under the core provision
400 square feet on qualifying 3,500–4,999-square-foot lots; up to 800 square feet on qualifying larger lots
Check the current zoning and development standards
Review deed and occupancy conditions in the current code
May not be sold separately; rental compliance remains required
What the headline does not settle.
These are the common edges that can move a project outside the protected or simplest path.
Lots below the statutory minimum do not qualify under the core provision.
Sewer proximity and Groundwater Protection Zone standards can require connection or a larger lot and treatment system.
Yard, environmental, utility, insurance, and federal program requirements remain.
What decides the actual lot.
Jurisdiction law is one layer. These checks turn it into a parcel-specific feasibility answer.
- Zoning district, legal principal dwelling, and the municipality's current ADU ordinance
- Lot coverage, setbacks, height, access, parking, and any nonconforming structures
- Sewer or septic capacity, water service, utilities, and fire access
- Wetlands, flood hazard, coastal, wildfire, historic, HOA, deed, and condominium restrictions
A practical verification path.
Stop at the first unresolved layer rather than designing past a constraint.
Confirm the parcel, governing municipality, zoning district, and legal use of the primary home.
Choose an internal, attached, or detached concept and test it against the controlling size and dimensional rules.
Retrieve the current zoning text, permit checklist, utility records, and every overlay that applies to the site.
Resolve wastewater, building, fire, access, environmental, and private-title constraints before final design.
Submit the required plans, complete inspections, and obtain every approval and occupancy document before use.
Sources behind this guide.
Official sources support published legal claims. Comparison sources are labeled and used for orientation only.
Reviewed August 6, 2026.
Jurisdiction rules are the start, not the verdict.
The free guide is live. Property-specific paid briefs will open only after local source coverage is verified.
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