Wildomar
493 sq ft · Studio · 1 ba
Studio
Wildomar · Plan 3447
29' × 17' footprint, from the plan sheet
Wildomar, Riverside County
Will an ADU fit in your Wildomar back yard?
Enter your address and we will draw your real parcel boundary, subtract the setbacks and your existing house, and show you what is actually left to build on. Then you can drag any of Wildomar's 6 pre-approved plans onto it.
- Free
- No account
- No phone number
- Your result first
Aerial: USGS/USDA NAIP
Local context
The Wildomar picture
The oldest housing stock and the biggest backyards of any city we serve, with the highest rate of owner-occupancy. Small city, but the lots are the best fit for a detached ADU.
- 7,500Detached single-family homes
- 1992Median year built
- 78%Owner-occupied
- $2,003Median rent
Wildomar permitted 12 ADUs in 2025, against 9 in 2023. Source: state Housing Element annual progress reporting.
The standards
The rules that apply to your lot
Every figure shows its source. Read from WMC Ch. 17.195 (Ord. 247, 1/15/2025; Ord. 256, 11/12/2025).
- 4ftSide and rear setbackWildomar code
- 1,200sq ftLargest detached ADU Wildomar allowsWildomar code
- 10ftClearance from your houseWildomar code
- 60daysDecision deadlineWildomar code
All 14 standards, with sources
| Standard | Value | Source |
|---|---|---|
| Side setback | 4 ft | Wildomar code |
| Rear setback | 4 ft | Wildomar code |
| Detached height | 16 ft Baseline; higher near transit | California minimum |
| Size the city must allow | 800 sq ft Cities cannot prohibit at least this size | California minimum |
| Largest detached ADU allowed | 1200 sq ft | Wildomar code |
| Distance from your house | 10 ft A flat 10 ft between the ADU and any other structure on the lot. This does not vary by zone, despite what the city’s own guidebook says. | Wildomar code |
| Front setback | 20 ft | Wildomar code |
| Parking | 1 space per unit One per ADU or one per bedroom, whichever is less. State transit exemptions still apply. | Wildomar code |
| Junior ADU maximum | 500 sq ft | Wildomar code |
| Decision deadline | 60 days And on a denial the city must give you a full list of deficiencies with how to fix each one — the only city of the six that writes that into its code. | Wildomar code |
| Owner-occupancy required | No | California minimum |
| HOA can prohibit an ADU | No Gov. Code §66315. Reasonable architectural standards still apply. | California minimum |
| Impact fees | Waived under 750 sq ft A real reason to consider staying just under the threshold. | California minimum |
| Pre-approved plan review | 30 days, ministerial AB 1332. No discretionary review, no hearing. | California minimum |
Anything Wildomar publishes inconsistently is left off this table rather than guessed at. Where that happens we say so in the notes above.
Easy to miss
Wildomar-specific requirements most people miss
These are in Wildomar's own code and they are not in the other cities we cover. They are also absent from every competitor page we audited.
Street-yard placement is possible here
If the Chief Building Official finds nothing else fits outside the 4 ft side and rear setbacks, Wildomar allows an ADU up to 800 sq ft in the street-yard setback — and even in front of the main house with a 20 ft front setback, if it suits the neighborhood. That is unusually flexible and it rescues some otherwise-dead lots.
Will-serve letter required
You need a will-serve letter from your water district before permitting.
No ADU after an SB 9 lot split
Wildomar prohibits any ADU or junior ADU on a lot that has been through an SB 9 urban lot split. If you are weighing a split against an ADU, in Wildomar it is one or the other.
Conflicting sources
Where Wildomar's own handouts disagree with its ordinance
We read the adopted code against the PDFs handed out at the counter. They do not match, and planning around the handout can cost real money.
The handout says
Wildomar’s guidebook says separation is 7 or 10 ft depending on your zone.
The code says
The adopted code sets a flat 10 ft from any other structure on the lot, with no zone variation. Do not plan around the 7 ft figure.
Wildomar ADU Guidebook vs. WMC §17.195.050
The handout says
Wildomar’s ADU handout cites "WMC Chapter 17.204".
The code says
There is no Chapter 17.204 in Title 17. The ADU chapter is 17.195. The handout is stale, which is worth knowing if you are trying to look up the rule yourself.
Wildomar ADU info PDF vs. WMC Title 17
The adopted ordinance governs. If a counter answer conflicts with it, ask which section they are relying on.
Wildomar's pre-approved ADU plans
6 designs Wildomar has already reviewed, drawn to the same scale.
Wildomar
646 sq ft · 1 bd · 1 ba
One Bedroom
Wildomar · Plan 3448
38' × 17' footprint, from the plan sheet
Wildomar
749 sq ft · 2 bd · 1 ba
Two Bedroom A
Wildomar · Plan 3449
35' × 28' envelope — the building is L-shaped
Wildomar
1,139 sq ft · 2 bd
Two Bedroom B
Wildomar · Plan 3450
34' × 31' envelope — the building is L-shaped
Wildomar
994 sq ft · 3 bd
Three Bedroom A
Wildomar · Plan 3451
38' × 29' envelope — the building is L-shaped
Confirm the final square footage with the city.
Wildomar
1,195 sq ft · 3 bd
Three Bedroom B
Wildomar · Plan 3446
43' × 34' envelope — the building is L-shaped
General plan
400 sq ft · Studio · 1 ba
Studio
Any city
About 20' × 20' — we derived this from the floor area
General plan
600 sq ft · 1 bd · 1 ba
1 Bedroom
Any city
About 25' × 24' — we derived this from the floor area
General plan
800 sq ft · 2 bd · 1 ba
2 Bedroom
Any city
About 31' × 26' — we derived this from the floor area
General plan
1,000 sq ft · 2 bd · 2 ba
2 Bed / 2 Bath
Any city
About 33' × 30' — we derived this from the floor area
Via the PRADU (Pre-Approved ADU). A pre-approved plan is reviewed ministerially in 30 days — no hearing, no neighbour objection. Plan sets free from the city.
Where a footprint is marked approximate we derived it from the published floor area and use it only for siting geometry, never as the building design.
Before you spend
What could stop your project in Wildomar
The geometry is usually the easy part. These are the issues that actually kill projects here.
Septic rather than sewer
Large parts of rural Wildomar east of I-15 rely on septic systems rather than sewer. An ADU on septic needs a capacity review, which can add significant cost.
Check your parcel is even in the city
Several communities here carry a Wildomar mailing address while sitting in unincorporated Riverside County — which means county permitting, under different standards and timelines.
The single most common planning mistake in this area, and worth two minutes to confirm before you pay anyone for drawings.
By neighborhood
Wildomar neighborhoods
Build era, lot depth, septic versus sewer, association rules and fire zone status all change the answer, and they change neighborhood by neighborhood rather than city-wide. Here is what we know about yours.
How this works
- 1
We find your parcel
Your real lot shape from the Riverside County Assessor, not a square around a pin.
- 2
We subtract the setbacks
Wildomar's setbacks, your house, and the clearance between buildings. Green is what is left.
- 3
You drag a real plan in
Fits, tight, or unlikely — and the best position we can find for it, not wherever you dropped it.
What you actually get
A report on your own parcel, in about a minute, before we ask you for anything.
- Your parcel, not an average. Your real boundary from Riverside County GIS, your house footprint, and the buildable area left after Wildomar's setbacks.
- You see it before you give us anything. The map, the numbers and the fit verdict are on screen first. The email is for keeping a copy.
- One call, from a person. We call you ourselves within one business day to go through it. No call centre, and your number is never resold — see the privacy policy.
FitsStudio, 493 sq ft
- Lot size
- 7,232 sq ft
- What is on it
- house 1,848 sq ft
- Buildable after setbacks
- 2,467 sq ft
- Side and rear setback
- 4 ft
- Plans that fit
- 4 of 11 we checked
Next: a call to walk through it, then one screened local builder if you want quotes. What it costs.
Computed for an ordinary 60 × 120 ft tract lot with a 40 × 46 ft house, using Wildomar's own setback and separation. Your figures come from your own parcel.
Wildomar ADU questions
How big an ADU can I build in Wildomar?
California requires every city, Wildomar included, to allow an ADU of at least 800 square feet. Whether that size fits on your lot after setbacks and the separation from your existing house is a different question entirely, and it depends on your parcel rather than on the city. That is what the tool answers.
What setbacks apply?
For a new detached ADU, state law caps the side and rear setback at 4 feet, so Wildomar cannot require more. We apply that to your parcel boundary. One honest limitation: we erode the parcel evenly rather than identifying which edge fronts the street, which makes the buildable zone slightly generous at the front — so we disallow front-yard placement in the tool entirely.
Can my HOA stop me?
No. Government Code section 66315 voids HOA covenants that prohibit or unreasonably restrict an ADU on a single-family lot. Your association can still apply reasonable architectural standards, and in practice that means an architectural committee submission running in parallel with your city permit. Budget calendar time, not a fight. Submit to both at once rather than waiting for one to finish.
Do I have to live on the property?
No. AB 976 made the prohibition on owner-occupancy requirements permanent, so neither Wildomar nor the state can require you to live in either unit.
Will an ADU reassess my property taxes?
Building an ADU triggers a reassessment of the new construction only, not of your existing home. Your original Proposition 13 base year value on the house is not disturbed. The assessor adds the value of what you built. We are working on a Wildomar-specific breakdown including how this interacts with any existing special district assessments on your parcel.
Which builder will I be sent to?
One licensed builder, exclusive to Wildomar, and we tell you who they are before we introduce you. We are not a contractor and we do not take a cut of your build — we are paid for the introduction, which is why we have no incentive to talk you into a bigger project than your lot supports.
Other cities we cover
See what fits on your Wildomar lot
Free. You see the result before we ask for anything.