Zoning, building permits and septic rules in Downey, California
Downey is a city in Los Angeles County, California. 5 rules below are quoted from official sources and independently re-checked, most recently on October 22, 2026. Rules for unincorporated land are on the Los Angeles County page.
Answers from the rulebook for Downey
Downey’s own rules
Building permitRequired
Construction, enlargement, alteration, repair, move, demolition, or occupancy change of buildings and structures inside Downey city limits
Application to the building official and a permit must be obtained before the work begins (§8999.28(a)).
Work exempt from permits under section 8105.2 is referenced as exempt, but exemptions do not authorize work that violates the code (§8999.28(b)).
Permit fees are payable per the city schedule of fees established by council resolution; permit is not valid until fees are paid (§8999.36(a)-(b)).
Chapter does not apply to applications filed before January 1, 2020 (§8999.20(b)).
“shall first make application to the building official and obtain the required permit.”
Building code adoptedAdopted
Building construction, alteration, and occupancy inside Downey city limits, under Downey Municipal Code Article VIII Chapter 14 (Downey Administrative Building and Housing Code)
The opened code text does not state the edition year of the California codes it applies; the city Building Code page (not opened, HTTP 403 to WebFetch) lists 2025 editions in a search snippet and says local amendments are in the Municipal Code.
Detached one- and two-family dwellings and townhouses not more than three stories above grade plane may comply with the California Residential Code instead, per the residential code paragraph in §8999.20(d)(2).
Chapter does not apply to any building or structure for which a plan check, construction or demolition application was made before January 1, 2020 (§8999.20(b)).
Chapter was added by ord. 20-1432, adopted 2-11-20, as stated on the page.
“the codes listed in this section and referenced elsewhere in this chapter, shall be considered part of the requirements of the municipal code to the prescribed extent of each such reference.”
InspectionsRequired
Work for which a building permit is required inside Downey city limits
Work must remain accessible for inspection until approved, and covered work must not be concealed until the building official authorizes it (§8999.38(a)).
Inspections are requested by the permit holder or agent and the building official approves or rejects the portion (§8999.38(b)).
Inspections do not approve violations of the code or other city ordinances (§8999.38(a)).
“construction or work for which a permit is required shall be subject to inspection by the building official”
Certificate of occupancyRequired
Use or occupancy of buildings or structures, and changes of occupancy classification, inside Downey city limits
Exceptions stated on the page: certificates of occupancy are not required for work exempt from permits under section 8105.2; accessory buildings and structures classified as U occupancy; all R-3 occupancies (§8999.40(a)).
Building official may issue a temporary certificate of occupancy before all work is complete, valid for a set period, with a processing fee (§8999.40(c)).
Certificate content and revocation are governed by §8999.40(b) and (d).
For commercial or industrial buildings with posted live loads, the certificate is not issued until floor load signs are installed (§8999.30(b)).
“no building or structure shall be used or occupied, and no change in the existing use or occupancy classification of a building or structure or portion thereof shall be made, until the building official has issued a certificate of occupancy therefor as provided herein.”
Permit processPartial
Building permit applications for work inside Downey city limits
Process is described in the code: application, submittal documents, plan review and permit placement (§8999.28, §8999.32, §8999.36).
Submittal documents require two or more sets with each application; the building official may waive some submittals (§8999.32(a)).
Fee amounts are set in a city schedule adopted by council resolution, which is not reproduced on the opened code page.
City administrative application forms and the city online permit portal were not opened.
“submittal documents consisting of construction documents, statements of special inspections, geotechnical report and other data shall be submitted in two or more sets with each permit application.”
Still unanswered
We looked and could not find an official answer yet. Silence is not permission; ask Downey or Los Angeles County directly.
Owner-builder exemption — Owner-builder permit for an owner-occupied home inside Downey city limits
Local zoning — Whether Downey city administers its own zoning ordinance for land inside city limits
Zoning districts — Zoning district map and district list for land inside Downey city limits
Minimum dwelling size — Single-family dwellings inside Downey city limits
Minimum lot size — Main single-family residential district (R-1 or equivalent) inside Downey city limits
20 more unanswered
Setbacks
Lot coverage
Building height
Living in an RV
Camping on your land
Tiny homes
Manufactured homes
Accessory dwellings
Who permits septic
Septic permit
Septic inspection
Off-grid sanitation
Well permit
Mandatory utility hookup
Agricultural exemption
Subdividing land
Driveway access
Building in a floodplain
Short-term rentals
Permit fees
Each answer was extracted from an official source and independently re-checked against that source by a second reviewer. That is an evidence check, not legal advice. Rules change; confirm with the authority before you buy or build.
Unanswered questions are usually a sign that Downey publishes no rule on the point, not that none exists. Los Angeles County’s page lists the county offices to call.
Off-grid gear
Going off-grid in Downey means bringing your own water and power. The kit we’d start with:
