ADU Constructionin South Pasadena, CA
ADU construction in South Pasadena follows state ADU law plus the city's Ordinance 2356 of 2021, which reviews ADUs ministerially within 60 days of a complete application and allows one ADU and one junior ADU on a single-family lot. The state housing department says that ordinance may be outdated, so confirm sizes and height with the city first.
South Pasadena was incorporated in 1888, long before anyone wrote an ADU rule. The Census Bureau's 2024 five-year estimates count 4,801 single-family detached homes among 10,817 units, about 44 percent, and about 33 percent of all units date from 1939 or earlier. Old houses with rear garages are the lots that state ADU law is written around, and in 2021 the city published its own design guidelines for ADUs on historic properties.
This page covers which ordinance applies, how historic lots are treated, size and height, the hill and fire zone rules, garage conversions and parking, fees and utilities, and how a job runs. The ordinance we could read is Ordinance 2356 of May 5, 2021, and a February 27, 2026 letter from the state housing department says the city's ordinance on file may be outdated, so every ADU number below may be outdated too. Where we cite the municipal code, the text comes from a GoCodebook mirror, because the city's code publisher blocked our tools. Confirm sizes, height and parking with the city's ADU information sheet and Community Development staff before you design. Prices and phases are on our ADU construction page, and the South Pasadena area page lists every trade we cover here.
South Pasadena Community Development rules that apply to ADU construction
Where adu construction permits come from in South Pasadena: City of South Pasadena Community Development Department, Building Division.
- Ordinance 2356 (passed May 5, 2021) amended Zoning Code 36.350.200: ADUs are reviewed ministerially within 60 days of a complete application, one ADU plus one junior ADU are allowed on a single family lot, a new detached ADU may be 150 to 1,200 square feet and an attached ADU up to 850 square feet (one bedroom) or 1,000 square feet (two or more), a JADU is capped at 500 square feet, and heights are 16 feet for one story and 18 feet flat or 22 feet pitched for two stories. New ADUs need setbacks of no more than 4 feet from side and rear lines, and up to 800 square feet of ADU may exceed lot coverage and FAR.
- Under Ordinance 2356, no off-street parking is required for an ADU within one half mile walking distance of a bus stop or light rail station, within an historic district or on a designated historic property, or inside the existing home, but a one space requirement applies otherwise. In the high risk fire area (south of Monterey Road and west of Meridian Avenue) fire sprinklers are required, a detached ADU must sit within 150 feet of the front property line, and one off-street space is required on streets narrower than 28 feet.
- For ADUs on historic properties, Ordinance 2356 requires placement in the rear with at least 50 percent of the first floor front facade behind the main massing, one story only and no more than 16 feet, and the city's 2021 guidelines say no attached ADU is permitted for a historic residence because it needs discretionary review. Demolishing an accessory structure on a historic property or 45 years or older needs a Certificate of Appropriateness before the ADU application is complete.
- The city's ADU amendments information sheet says ADUs are non-discretionary approvals, that state law lets ADUs within one mile of a major transit stop reach 18 feet and attached ADUs 25 feet, and that the code is being updated to reflect Government Code 66323, which HCD reads as allowing up to four units on a single family property (primary unit, converted ADU, new ADU and JADU).
- A February 27, 2026 HCD letter says the most recent South Pasadena ADU ordinance on file with HCD is from 2021 and may be outdated and out of compliance with state ADU law, and lists 2025 state changes such as no impact fees for ADUs of 750 square feet or less and a 15 business day completeness check. Ask the city which standards it applies to a new ADU today.
Which ADU rules apply in South Pasadena: the 2021 ordinance or state law?
Both, and where they differ the state law wins. The ordinance we read amended Zoning Code 36.350.200 on May 5, 2021. A February 27, 2026 letter from the Department of Housing and Community Development says the most recent South Pasadena ordinance on file with the state is from 2021 and may be outdated and out of compliance with state ADU law. The letter lists 2025 changes such as no impact fees for ADUs of 750 square feet or less and a 15 business day completeness check.
The city's own ADU amendments sheet says ADUs are non-discretionary approvals, that state law lets ADUs within one mile of a major transit stop reach 18 feet and attached ADUs 25 feet, and that the code is being updated to reflect Government Code 66323. The housing department reads that section as allowing up to four units on a single-family property: the primary home, a converted ADU, a new ADU and a junior ADU. We could not read the city's updated text, so ask Community Development which standards it applies to a new application today.
- Which ordinance version will the plan checker use for my address?
- Is the lot in a historic district or on the Inventory?
- Is the lot south of Monterey Road and west of Meridian Avenue?
Building an ADU on a historic property in South Pasadena
The Inventory of Cultural Resources holds 2,718 properties and district contributors, and the Cultural Heritage Commission, established in 1971, reviews exterior changes to them. For an ADU on a historic property, Ordinance 2356 requires placement in the rear, with at least half of the first-floor front facade behind the main massing, one story only and no taller than 16 feet. The city's 2021 guidelines add that no attached ADU is permitted for a historic residence, because it would need discretionary review.
If an accessory structure on a historic property, or any accessory structure 45 years or older, has to come down, a Certificate of Appropriateness is needed before the ADU application is complete. We did not open the Cultural Heritage Ordinance, so we cannot give its full thresholds. Sources also disagree on the district count: the 2021 guidelines say nine formally designated residential historic districts, and the Los Angeles Conservancy lists five. Ask Planning whether your parcel is in one, because the answer changes the parking rule, the footprint and the review path.
How big can an ADU be in South Pasadena, and how tall?
Under the 2021 ordinance, a single-family lot may carry one ADU plus one junior ADU. A new detached ADU may run 150 to 1,200 square feet, an attached ADU up to 850 square feet with one bedroom or 1,000 with two or more, and a junior ADU is capped at 500 square feet. Height is 16 feet for one story, and a two-story ADU is limited to 18 feet with a flat roof or 22 feet with a pitched one.
New ADUs need setbacks of no more than 4 feet from the side and rear lines, and up to 800 square feet of ADU may exceed the lot coverage and floor area limits. State law backs those floors: a city may not cap an ADU below 850 square feet, or 1,000 with more than one bedroom, and must still allow 800 square feet with 4 foot setbacks. Because the city says its code is being updated, treat every figure here as possibly outdated and have the plan checker confirm it.
ADUs in the Monterey Hills and the high fire zone
In the high risk fire area, south of Monterey Road and west of Meridian Avenue, the 2021 ordinance requires fire sprinklers in an ADU and requires a detached ADU to sit within 150 feet of the front property line. It also asks for one off-street space on streets narrower than 28 feet. Chapter 14.1 of the municipal code treats parcels partly inside the local high zone as very high, and the city has adopted the 2025 California Wildland-Urban Interface Code. State law says an ADU does not need sprinklers when the main house does not, and the 2021 ordinance predates the latest state changes, so ask which one governs your lot.
Hillside lots with an average slope of 20 percent or more fall under Division 36.340, which brings a Hillside Development Permit, Design Review and a geotechnical report, with retaining walls capped at 6 feet. The Altos de Monterey overlay adds its own height, setback and lot coverage limits. We did not read whether a hillside ADU triggers those permits in every case. The Southwest Monterey Hills booklet, a 2015 city handout, adds vehicle limits, a 2:00 p.m. street cutoff and a deputy inspector deposit for grading and heavy equipment, so ask before you price a canyon site.
Garage conversion ADUs and the parking rule in South Pasadena
The city's historic guidelines say most driveways run along the side yard to a rear garage, which makes that garage the easiest footprint to convert. The 2021 ordinance requires no off-street parking when the ADU is within one half mile walking distance of a bus stop or light rail station, in a historic district, on a designated historic property or inside the existing home. Otherwise it asks for one space. State law is plainer: it bars replacement parking when a garage, carport or covered space is converted.
A conversion still needs a permit from the Building Division. The detailed conversion checklist we found belongs to the City of Los Angeles, so we do not apply it to South Pasadena. In any city, the part of an old garage to inspect first is the slab, the walls, the electrical panel, the sewer line and the records of earlier permits, and a historic garage that must be demolished needs the Certificate of Appropriateness first.
ADU fees, utilities and the state clocks in South Pasadena
We did not read a South Pasadena fee schedule. The Building Division page links a Los Angeles County Public Works fee schedule written for unincorporated territory, which does not apply to a city address, so permit and plan check charges stay out of this page and appear as their own lines in a proposal. State law sets two limits worth knowing: no impact fee on an ADU of 750 square feet or less, and utility connection or capacity charges stand apart from that exemption. An ADU converted from existing space cannot be forced to take a new utility connection or pay a related fee.
State law also sets the clocks. The city must tell you in writing within 15 business days whether the application is complete, then approve or deny within 60 days, and silence for 60 days means deemed approval. A denial must list every defect, and an appeal gets a final answer within 60 business days. The 2021 ordinance also sets 60 days. We could not verify the Building Division's real turnaround, so ask for the current queue.
A new detached ADU is usually trenched for sewer, water and power, and the length of that run is the swing item in many budgets. Ask whether the existing electrical panel and the sewer lateral can carry a second home.
How to build an ADU in South Pasadena: pre-approved plans and the job schedule
South Pasadena is working on a pre-approved ADU plan program. A March 18, 2026 city press release invited input at a community meeting on March 26, 2026, at the Library Community Room, 1115 El Centro Street, and says the city plans three sizes and architectural styles that reflect its neighborhoods, plus an ADU Guide. We found no adopted program and no cost figure, so do not plan around it yet. Ask Community Development whether the plans exist today.
After the application, a job runs through plans, the completeness check, the city decision, scheduling, construction and the final inspection. The schedule on our ADU page puts a garage conversion at 3 to 5 months of construction and a detached unit at 5 to 9 months, which are MDG planning estimates rather than city data. As MDG Builders, CSLB #1040337, we draw the plans, file the application and manage the build, and licensed subcontractors do the framing, plumbing, electrical and finish work. The post on ADU vs JADU in California explains the junior unit, and the garage conversion permit steps show what a conversion file looks like in Los Angeles.
ADU photos from South Pasadena and nearby homes
ADU scenes tied to South Pasadena and the neighborhoods around it, from garage conversions and utility trenches to finished cottages. Tap a photo to enlarge it.
What adu construction costs around South Pasadena
Our ADU construction page prices a garage conversion to a studio or one bedroom at roughly $100,000 to $200,000 and a new detached unit of 400 to 800 square feet at roughly $200,000 to $400,000. Those ranges rest on a UC Berkeley survey of Los Angeles County households that completed or applied for an ADU in 2018 and 2019 (median $100,000, with $90,000 for garages and $180,000 for detached units), the Terner Center's 2020 Los Angeles estimate of $148,000, and Remodeling magazine's 2025 Cost vs. Value job cost of $178,536, of which 39.9 percent came back at resale. None is a South Pasadena quote, and we did not read any city fee amounts. Hillside access, a fire zone sprinkler line or a long utility trench can push a lot toward the top of its range. The ADU cost guide and the room addition versus ADU post go deeper. Nearby cities apply state law their own way, so compare ADU construction in Pasadena, Alhambra, San Gabriel, Monterey Park and Los Angeles. A bath inside the unit is on our South Pasadena bathroom page, an attached addition on the South Pasadena room addition page, and the windows for the new unit on the South Pasadena window page.
| What it covers | Typical range |
|---|---|
| Garage conversion to a studio or one bedroom | $100,000 to $200,000 |
| New detached ADU, 400 to 800 sq ft | $200,000 to $400,000 |
| UC Berkeley survey, Los Angeles County median, 2018 and 2019 projects | $100,000 overall. $90,000 garage. $180,000 detached. |
| Terner Center and Berkeley CCI, 2020 | $148,000 Los Angeles estimate. $167,000 statewide average. |
| Remodeling Cost vs. Value 2025, Los Angeles | $178,536 job cost |
| Electrical and plumbing, Angi Los Angeles, January 2026 | Electrical $2,600 to $7,800. plumbing $3,900 to $10,400. |
| City permit and plan check fees | Not priced here |
Other work we manage in South Pasadena
South Pasadena ADU questions, answered
Can I build an ADU in South Pasadena?
Yes. State law and the city's 2021 ordinance both allow ADUs on lots with a house, and the city reviews them ministerially within 60 days of a complete application. One ADU plus one junior ADU fit on a single-family lot under the ordinance, and the city says it is updating its code toward the state's four-unit reading. Confirm current rules with Community Development.
How do I build an ADU in South Pasadena?
Start with Community Development to confirm the ordinance version, historic status and fire zone, then draw plans, apply through the Building Division and wait for the completeness check and the decision. Construction follows permit issue, with inspections and a final. A general contractor can run the whole sequence while licensed subcontractors do the field work.
How big can an ADU be in South Pasadena?
Under the 2021 ordinance, a detached ADU may be 150 to 1,200 square feet, an attached one up to 850 square feet with one bedroom or 1,000 with more, and a junior ADU up to 500. Height is 16 feet for one story, and a pitched two-story unit may reach 22 feet. The state housing department says these numbers may be outdated, so confirm them.
How much does it cost to build an ADU in California?
Our working ranges are roughly $100,000 to $200,000 for a garage conversion and $200,000 to $400,000 for a new detached unit of 400 to 800 square feet. They rest on 2018 to 2025 studies of Los Angeles County and Los Angeles, not on South Pasadena quotes, and permit fees are separate lines. A written proposal gives the price for your lot.
Do I need to provide parking for my ADU?
Often no. The 2021 ordinance requires none within one half mile walking distance of a bus stop or light rail station, inside a historic district, on a designated historic property or inside the existing home, and otherwise one space. State law bars replacement parking when a garage is converted. Confirm which rule the city applies to your address.
What is the difference between an ADU and a JADU?
A junior ADU is a unit of up to 500 square feet built inside the existing single-family house, while an ADU can be a detached or attached unit of larger size. A JADU needs an efficiency kitchen and a separate entry, and state law requires owner occupancy only when it shares a bathroom with the house.
Can I rent out my ADU or sell it separately?
You can rent it, and state law lets a city require terms of 30 days or longer, so short-term rentals are limited. It cannot be sold apart from the house, except to a qualified low-income buyer through a qualifying nonprofit or under a condominium ordinance the city has adopted. We found no South Pasadena condominium ordinance, so ask the city.
How long does it take to get an ADU permit?
State law gives the city 15 business days to say whether the application is complete and 60 days after that to approve or deny, with silence meaning deemed approval. The city's 2021 ordinance also sets 60 days. Corrections and appeals add time, and we could not verify the Building Division's real turnaround.
Do I need a permit to convert my garage into an ADU?
Yes. A garage conversion is an ADU and needs a building permit through the Building Division, plus a Planning Clearance. If the garage is on a historic property or is 45 years or older and must be demolished, a Certificate of Appropriateness comes first. Ask Community Development for its checklist before you design.
Can my HOA stop me from building an ADU?
Not by banning it outright. California law, as the state housing department's handbook describes it, voids covenants that effectively prohibit or unreasonably restrict an ADU or junior ADU on a single-family lot, though reasonable rules may remain. We did not read any South Pasadena association documents, so check yours before you design.
Tell us about your South Pasadena ADU
Tell us the neighborhood, whether the lot is on the hill, in a historic district or south of Monterey Road, whether you are weighing the garage or the backyard, and how old the house is, and we will plan the first visit around the review path.