Town Permit Guide

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Can I build an ADU in Morro Bay, California?

Morro Bay, San Luis Obispo County · Ordinances checked 2026-10-05 · Reviewed · 13 cited sections

Allowed with a permit

Yes. ADUs are permitted in all of Morro Bay's residential districts and get ministerial approval within 60 days. A single-family lot can have one detached ADU (up to 1,000 sq ft, or 1,200 sq ft with 2+ bedrooms), one converted ADU and one junior ADU (up to 500 sq ft). New ADUs need only 4-foot side and rear setbacks. In the coastal zone you may also need a coastal development permit.

Allowed inRL, RS, RM and RH districts (permitted use) [1]
Units on a single-family lot1 detached ADU + 1 converted ADU + 1 JADU [2]
Max size, detached ADU1,000 sq ft (studio/1-bed); 1,200 sq ft (2+ bed) [3]
Max size, attached ADU1,000 sq ft [4]
Side and rear setbacks4 ft minimum [5]
Max size, JADU500 sq ft [6]
ParkingNone required, except 1 space per unit in the mapped coastal parking area [7]
Minimum rental term30 consecutive days [9]
ReviewMinisterial, within 60 days of a complete application [10]
Impact feesNone for ADUs of 750 sq ft or less [12]

Where and how many

ADUs are a permitted use in the RL, RS, RM and RH residential districts [1], and in the agriculture district. On a lot with an existing or proposed single-family home, you can have one detached ADU, one ADU converted from existing space in the home or an accessory structure, and one junior ADU (JADU) inside the house or attached garage [2]. Multi-unit lots get more detached and converted ADUs but no JADUs.

Size, setbacks and design

  • Detached: up to 1,000 sq ft for a studio or one-bedroom, 1,200 sq ft with two or more bedrooms [3].
  • Attached: up to 1,000 sq ft [4].
  • Setbacks: the district's normal setbacks apply, except interior side and rear setbacks are 4 feet [5]. Converting an existing legal structure needs no added setback.
  • Design: exterior design and materials must match the main house.
  • JADU: up to 500 sq ft with an efficiency kitchen [6].

Parking

No parking is required for an ADU, and a garage converted to an ADU doesn't need replacement parking [13]. The exception is the coastal area shown in Figure 17.14.040(B)(2): there, one off-street space per unit is required, and converted garage parking must be replaced [7]. State law bars ADU parking requirements within half a mile walking distance of public transit and replacement parking for converted garages, so this may not apply to every lot.

Owner-occupancy and rentals

There's no owner-occupancy rule for ADUs. For a JADU, the code requires the owner to live in the house or the JADU only when the JADU has its own bathroom [8]. State law allows an owner-occupancy requirement only for a JADU that shares a bathroom, so state law may override this provision. ADUs can be rented, but rentals must be at least 30 days [9], and ADUs can't be sold separately from the house except as state law allows.

Approvals and fees

Applications are approved ministerially, without a hearing, within 60 days of a complete application [10]. In the Coastal Resource Protection overlay, a coastal development permit may be required [11]. ADUs there must avoid harm to coastal resources, including habitat buffers and bluff setbacks. No impact fees apply to ADUs of 750 sq ft or less [12]. Morro Bay also offers pre-approved ADU stock plans through a regional program.

Coming in 2027

Starting January 1, 2027, state law (AB 956) will require cities to approve two new detached ADUs on a single-family lot (without a JADU when both are built). Morro Bay's code currently lists one.

See how Morro Bay compares with 8+ other California towns on accessory dwelling units (adus) →

Next steps

  1. Check your district and whether you're in the Coastal Resource Protection overlay or the coastal ADU parking area with the Community Development Department (955 Shasta Avenue, 805-772-6267).
  2. Consider the city's pre-approved ADU stock plans to speed up review.
  3. Submit an ADU building permit application with site plan, floor plans and elevations showing 4-ft side/rear setbacks and the unit's interior square footage.
  4. If a coastal development permit is required, ask Community Development about timing; state law requires coastal permit decisions on ADUs within 60 days without a hearing.

Common questions

Can I build an ADU in Morro Bay, California?
Yes. ADUs are a permitted use in Morro Bay's RL, RS, RM and RH residential districts and are approved ministerially, without a hearing, within 60 days of a complete application. In the Coastal Resource Protection overlay you may also need a coastal development permit.
How big can an ADU be in Morro Bay, California?
A detached ADU can be up to 1,000 sq ft for a studio or one-bedroom, or 1,200 sq ft with two or more bedrooms. An attached ADU can be up to 1,000 sq ft, and a junior ADU up to 500 sq ft.
How many ADUs can I have on a single-family lot in Morro Bay, California?
One detached ADU, one ADU converted from existing space and one junior ADU. Starting January 1, 2027, state law (AB 956) will require cities to approve two new detached ADUs on a single-family lot.
Do I need parking for an ADU in Morro Bay, California?
Usually not. No parking is required for an ADU, except in the mapped coastal area, where one off-street space per unit is required and converted garage parking must be replaced. State law may override that rule near public transit.
Can I rent my ADU short term in Morro Bay, California?
No. ADUs can be rented, but rentals must be at least 30 days, and ADUs and JADUs can't be used as short-term rentals. There's no owner-occupancy rule for ADUs.

California's statewide ADU law

California's ADU law (Gov. Code §§66310–66342, recodified from §65852.2; latest amendments effective January 1, 2026) overrides conflicting city rules, including in charter cities. Cities must approve ADUs ministerially (no hearing) within 60 days of a complete application, or the permit is deemed approved.

What cities cannot require or do:

  • Owner-occupancy for an ADU.
  • A minimum lot size.
  • Side or rear setbacks over 4 feet for a new ADU, or any setback for a converted existing structure.
  • Size, lot coverage or floor-area rules that block an ADU of at least 800 sq ft. Size caps can't be under 850 sq ft (1,000 for 2+ bedrooms).
  • Parking within half a mile walking distance of public transit, or replacement parking for a garage converted to an ADU.
  • Impact fees on ADUs of 750 sq ft or less.

By right on a single-family lot: one converted ADU plus one junior ADU (JADU, up to 500 sq ft inside the house), plus one new detached ADU (up to 800 sq ft, 16 ft tall). Owner-occupancy may be required only for a JADU that shares a bathroom.

Short-term rentals: cities may bar ADU rentals under 30 days, and must for by-right ADUs, JADUs and SB 9 units.

Coming January 1, 2027: AB 956 raises the by-right count to two new detached ADUs per single-family lot.

SB 9 (§§65852.21, 66411.7) allows two homes on a single-family lot, or a split into two lots of at least 1,200 sq ft (with a 3-year owner-occupancy affidavit).

State sources: Gov. Code §66314 (ADU ordinance standards) · Gov. Code §66315 (no owner-occupancy requirement) · Gov. Code §66317 (ministerial review, 60-day deadline) · Gov. Code §66321 (size, setback and height limits on local rules) · Gov. Code §66322 (parking exemptions) · Gov. Code §66323 (by-right ADUs and JADUs) · Gov. Code §66333 (junior ADUs) · Gov. Code §66311.5 (impact fees) · AB 956 (2026), Stats. 2026, ch. 791 · Gov. Code §65852.21 (SB 9 two-unit projects) · Gov. Code §66411.7 (SB 9 urban lot splits) · HCD, Accessory Dwelling Units (ADU Handbook, updated March 2026)

What the ordinance says

Exact text from Morro Bay's published ordinances. Section numbers are as printed in the source.

  1. Table 17.07.020, Municipal Code Title 17 Division II District Regulations (Ch. 17.07 residential districts; 17.11 waterfront and harbor area districts; 17.14 Coastal Resource Protection overlay), p. 1
    Accessory Dwelling Unit P P P P
  2. Sec. 17.30.040(C)(1), Municipal Code Title 17 Ch. 17.30 Standards for Specific Uses (17.30.040 ADUs; 17.30.060 animal keeping; 17.30.130 home occupations; 17.30.220 short-term vacation rentals; 17.30.270 urban agriculture), p. 1
    One detached accessory dwelling unit; and b. One accessory dwelling unit converted from existing space within a proposed or existing primary home or within the existing space of an accessory structure; and c. One junior accessory dwelling unit within the existing or proposed space of a single-unit dwelling, including an attached garage.
  3. Sec. 17.30.040(D)(1)(a), Municipal Code Title 17 Ch. 17.30 Standards for Specific Uses (17.30.040 ADUs; 17.30.060 animal keeping; 17.30.130 home occupations; 17.30.220 short-term vacation rentals; 17.30.270 urban agriculture), p. 1
    Maximum one thousand square feet of interior livable space for studio and one-bedroom accessory dwelling units, up to one thousand two hundred square feet of interior livable space for accessory dwelling units with two or more bedrooms.
  4. Sec. 17.30.040(D)(1)(b), Municipal Code Title 17 Ch. 17.30 Standards for Specific Uses (17.30.040 ADUs; 17.30.060 animal keeping; 17.30.130 home occupations; 17.30.220 short-term vacation rentals; 17.30.270 urban agriculture), p. 1
    The total floor area of an accessory dwelling unit that is attached to the primary dwelling unit shall not exceed one thousand square feet of interior livable space.
  5. Sec. 17.30.040(D)(2), Municipal Code Title 17 Ch. 17.30 Standards for Specific Uses (17.30.040 ADUs; 17.30.060 animal keeping; 17.30.130 home occupations; 17.30.220 short-term vacation rentals; 17.30.270 urban agriculture), p. 1
    Accessory dwelling units shall comply with the setback standards applicable to other structures within the district in which the lot is located except that the minimum interior side and rear setbacks shall be four feet.
  6. Sec. 17.30.040(E)(4)(a), Municipal Code Title 17 Ch. 17.30 Standards for Specific Uses (17.30.040 ADUs; 17.30.060 animal keeping; 17.30.130 home occupations; 17.30.220 short-term vacation rentals; 17.30.270 urban agriculture), p. 1
    Maximum five hundred square feet of interior livable space.
  7. Sec. 17.14.040(B)(2), Municipal Code Title 17 Division II District Regulations (Ch. 17.07 residential districts; 17.11 waterfront and harbor area districts; 17.14 Coastal Resource Protection overlay), p. 1
    For all ADUs and SB 9 development within the area shown in Figure 17.14.040(B)(2), the parking reductions specified in Section 17.07.030 A(6) shall not apply, and one off-street parking space per unit shall be required. If enclosed or covered parking for the primary dwelling is converted or demolished in conjunction with the construction of an ADU or SB 9 unit, off-street replacement parking is required.
  8. Sec. 17.30.040(E)(4)(d), Municipal Code Title 17 Ch. 17.30 Standards for Specific Uses (17.30.040 ADUs; 17.30.060 animal keeping; 17.30.130 home occupations; 17.30.220 short-term vacation rentals; 17.30.270 urban agriculture), p. 1
    The owner of the single-unit dwelling in which the junior accessory dwelling unit is located shall reside in either the remaining portion of the structure or the junior accessory dwelling unit, if the junior accessory dwelling unit includes separate sanitation facilities from the existing structure.
  9. Sec. 17.30.040(I), Municipal Code Title 17 Ch. 17.30 Standards for Specific Uses (17.30.040 ADUs; 17.30.060 animal keeping; 17.30.130 home occupations; 17.30.220 short-term vacation rentals; 17.30.270 urban agriculture), p. 1
    Rental terms shall be a minimum of thirty consecutive days.
  10. Sec. 17.30.040(J)(1), Municipal Code Title 17 Ch. 17.30 Standards for Specific Uses (17.30.040 ADUs; 17.30.060 animal keeping; 17.30.130 home occupations; 17.30.220 short-term vacation rentals; 17.30.270 urban agriculture), p. 1
    Permit applications for accessory dwelling units shall be considered and approved ministerially without discretionary review or a hearing within sixty days from receipt of a completed application if there is an existing single-family or multifamily dwelling on the lot or when the permit application for a proposed single-unit or multi-unit dwelling is acted upon.
  11. Sec. 17.30.040(J)(2), Municipal Code Title 17 Ch. 17.30 Standards for Specific Uses (17.30.040 ADUs; 17.30.060 animal keeping; 17.30.130 home occupations; 17.30.220 short-term vacation rentals; 17.30.270 urban agriculture), p. 1
    In the coastal resource protection (CRP) overlay district, a coastal development permit pursuant to Chapter 17.39, Coastal Development Permits (IP) may be required.
  12. Sec. 17.30.040(K)(1), Municipal Code Title 17 Ch. 17.30 Standards for Specific Uses (17.30.040 ADUs; 17.30.060 animal keeping; 17.30.130 home occupations; 17.30.220 short-term vacation rentals; 17.30.270 urban agriculture), p. 1
    ADUs with a floor area of seven hundred fifty square feet of interior livable space or less shall not pay development impact fees.
  13. Sec. 17.30.040(G), Municipal Code Title 17 Ch. 17.30 Standards for Specific Uses (17.30.040 ADUs; 17.30.060 animal keeping; 17.30.130 home occupations; 17.30.220 short-term vacation rentals; 17.30.270 urban agriculture), p. 1
    Automobile parking is not required for an accessory dwelling unit, except as provided in Section 17.14.040 B.
This page summarizes Morro Bay's posted ordinances as of 2026-10-05. Ordinances are amended, and individual lots can have overlays, subdivision covenants, or HOA rules that are stricter. Confirm with City of Morro Bay Community Development Department - Building Division (Building Inspector/Code Enforcement Officer 805-772-6213), 955 Shasta Avenue; Harbor Department handles waterfront enforcement (805-772-6267) before you build. Spot an error?