How big can an ADU be in Rio Rancho?

An accessory dwelling unit cannot exceed 900 square feet or 50% of the primary structure's floor area, whichever is greater, and the lot must be at least 7,000 square feet in area. Source: Rio Rancho Municipal Code § 154.03 (definitions) and § 154.70(A)(6).

Do I need a separate permit for an ADU in Rio Rancho?

An ADU requires zoning compliance with Rio Rancho Municipal Code § 154.70(A) design standards plus a standard building permit through the Building Permit & Plan Review Application process — the same process used for new residential construction.

Accessory Dwelling Unit (ADU) Permit in Rio Rancho, New Mexico

Verified

Rio Rancho zoning ordinance (Chapter 154) permits accessory dwelling units as an accessory use in residential zones, subject to size, lot area, and design standards. Requires both zoning compliance review and a building permit through the same Building Permit & Plan Review process as new construction.

Verified 2026-07-02 · Source

65% of the Building Permit Fee (non-refundable)Building Permit & Plan Review Application Fee

When you need this permit

Defined in Rio Rancho Municipal Code § 154.03 as a separate, complete housekeeping unit, attached or detached, not exceeding 900 square feet or 50% of the primary structure (whichever is greater), on a lot 7,000 square feet or greater, with a separate entrance, kitchen, sleeping area, and full bathroom facilities (not a mobile home)
Per § 154.70(A), accessory dwelling units are allowed in residential zones subject to design standards: shall not exceed the height of the primary structure or 24 feet, whichever is greater; exterior of any accessory dwelling unit over 250 sq ft must use materials/facade similar to the primary structure (over 600 sq ft must match materials/facade)
An additional parking space that does not block a two-car garage is required for an accessory dwelling unit
A second kitchen is permitted in the primary residence or the ADU, but not both
Building permit required through the standard Building Permit & Plan Review Application process, with plans reviewed against the 2021 IBC/IRC with New Mexico amendments

Required documents

Required
Residential Building Permit & Plan Review Application
Same application form used for new residential construction; used for ADU building permit submittal
Required
Site Plan showing ADU location, setbacks, and parking
Must demonstrate compliance with § 154.70(A) design standards and required additional parking space

Fee schedule

Fee type	Amount	Notes
Building Permit & Plan Review Application Fee	65% of the Building Permit Fee (non-refundable)	Residential Building Permit & Plan Review Application form, City of Rio Rancho Development Services — same fee structure as new residential construction

Review timeline

~10–15 business days

Typical estimate — confirm current times with the Rio Rancho building department

Inspection process

1
Foundation Inspection
After excavation for footings is complete and reinforcing steel is in place, before concrete is poured
2
Frame Inspection
After framing, fire blocking, bracing, and rough MEP trades are complete and approved
3
Final Inspection
When the structure is complete and ready for occupancy

Tips

An ADU cannot exceed 900 square feet or 50% of the primary structure's size, whichever is greater, and the lot must be at least 7,000 square feet — verify both before submitting plans.
An ADU may not be constructed without an existing primary structure/dwelling unit on the lot (Rio Rancho Municipal Code § 154.70(A)(4)).
An additional parking space that does not block access to a two-car garage is required for the ADU.
Contact the Planning & Zoning Division at (505) 891-5005 to confirm your property's zoning district allows an ADU before applying for a building permit.

Frequently asked questions

How big can an ADU be in Rio Rancho?: An accessory dwelling unit cannot exceed 900 square feet or 50% of the primary structure's floor area, whichever is greater, and the lot must be at least 7,000 square feet in area. Source: Rio Rancho Municipal Code § 154.03 (definitions) and § 154.70(A)(6).
Do I need a separate permit for an ADU in Rio Rancho?: An ADU requires zoning compliance with Rio Rancho Municipal Code § 154.70(A) design standards plus a standard building permit through the Building Permit & Plan Review Application process — the same process used for new residential construction.

Sources & verification

Verified against official sources. Last reviewed 2026-07-02.

Fees, timelines, and adopted codes are researched from each jurisdiction's published records — see how we verify. Requirements change and vary by project, so always confirm the current details with the Rio Rancho building department before you submit. PermitBase is an independent reference and is not affiliated with any government agency.

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Accessory Dwelling Unit (ADU) Permit in other cities

Albuquerque, New Mexico Las Cruces, New Mexico Santa Fe, New Mexico Unincorporated Bernalillo County, New Mexico Arvada, Colorado Aurora, Colorado Boise, Idaho Boulder, Colorado

Compare accessory dwelling unit (adu) permit fees across New Mexico →

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