ADUs in Rolling Hills Ranch & San Miguel Ranch

How the two communities came together

Rolling Hills Ranch

Rolling Hills Ranch was planned as Salt Creek Ranch, and the City's SPA library lists the two names together under PCM-90-02. Environmental review started in 1989, and one CEQA filing describes up to 3,644 units on 834.5 acres. A later phase, Subarea III, covered 607 acres and neighborhoods 9 through 12; its streambed alteration notice was posted in May 2002 for McMillin Rolling Hills Ranch, with Upper Otay Reservoir to the south and undeveloped land to the north and east.

Today the Rolling Hills Ranch Community Association describes 1,687 single-family homes in the hills north of Otay Ranch, next to Eastlake. It runs five swim clubs, nine tot lots and about 70 acres of common landscaping with more than 4,000 trees, and it has an on-site office on Old Trail Drive managed by Prescott. Architectural applications go to the association's assistant general manager.

San Miguel Ranch

San Miguel Ranch was in the works from the late 1980s. A 1996 environmental notice described 1,757 units on 476 acres at Proctor Valley Road and East H Street, near the Sweetwater River. When the City finalized annexation in December 2000, the ranch was reported at about 2,600 acres, with Trimark Pacific Homes planning about 1,400 homes on its southern section and the City's agreement setting aside about a quarter of the land as open space, with most of the rest also preserved. Its SPA is PCM-90-19.

Later tracts were large. Van Daele's 2011 release, for example, offered 56 detached homes of 2,427 to 3,273 sq ft, every plan with a three-car garage, next to 245 acres of open space, trails for hiking, biking and horses, and a 16-acre community park.

Master association review

Both communities are planned developments with a master association, so the City permit is only half the approval. Here is how the state rules apply:

• No outright ban. Civil Code 4751 voids CC&R rules that effectively prohibit or unreasonably restrict an ADU or JADU on a single-family lot. Reasonable rules on materials, colors and roof form are fine if they do not drive up cost unreasonably.
• Written answers. Civil Code 4765 requires a fair, prompt process with a stated deadline. If the answer is no, it has to come in writing with the reason and a path to a second look.
• No replacement parking demand. According to the Adams Stirling law firm, an HOA cannot require you to replace garage parking lost to an ADU conversion. That matters for a three-car garage.
• Rentals allowed. Civil Code 4741 stops associations from banning ADU rentals, though they may prohibit stays of 30 days or less. City and state rules already bar rentals shorter than 30 days.
• Views are unsettled. On view lots, whether an HOA can restrict an ADU to protect a neighbor's view has not been settled by the courts. A single-story design avoids most of the argument.

We did not find published ADU guidelines from either association, so expect the standard architectural application. AB 956 changes two things on January 1, 2027: Civil Code 4751 reaches lots "zoned to allow" single-family homes, and a second detached ADU becomes a right on single-family lots, so associations will see more applications. For the application itself, read the east-side ADU guide for Eastlake and Otay Ranch.

CFD 11M, CFD 2001-1 and your tax bill

The City formed CFD 11M for Rolling Hills Ranch in 2004. It pays for landscaping and storm water work, and the City lists its maintained areas as habitat, Johnson Canyon, Proctor Valley Road and storm water quality. San Miguel Ranch sits in facilities district CFD 2001-1 (Improvement Area B) and 2001-1A, according to the City's 2018 debt list. A facilities CFD for Rolling Hills Ranch did not appear on that list.

We could not read the rate formula for 11M or 2001-1. Other east-side maintenance districts tax living square footage taken from building permits, while the newest one, 16M, charges $50 per ADU a year. Either way an ADU may add to the special tax, so put the question to the City's CFD administrator while the size is still open. Expect the Otay Water improvement-district line on the bill to grow slightly as well, since it is charged on assessed value.

Hillside lots, open space and the fire map

Johnson Canyon, the Proctor Valley corridor and the San Miguel open space put a lot of these homes on a slope or against habitat. That changes three things:

1. Grading and footings. A pad cut into a slope or a lot above a manufactured bank may need a soils report, retaining walls or deeper footings. The cost calculator prices this as a slope add-on.
2. Fire hazard zone. The City adopted updated hazard zones in 2025 (Ord. 3598) and a new wildland-urban interface code in November 2025 (Ord. 3614). The City has not published a neighborhood list, so the contractor looks up each address in CVMapper. Reporting by inewsource put the growth of Chula Vista's Very High zone at no less than a tenth across the two map editions, and open-space edges like these are the first place to check. A rated lot then falls under the City's wildland-urban interface code, which generally means ignition-resistant materials.
3. Sprinklers. City code ties the ADU to the house here: no sprinkler requirement for the unit unless the home itself must have them.

Habitat and storm water areas maintained under CFD 11M are typically outside private lots, so keep any new structure, drainage and grading inside your own lot lines. On height, a detached unit here is usually held to 16 ft unless a qualifying transit stop is within a half-mile, while an attached ADU can reach 25 ft and two stories, which can suit a large two-story house.

Water, fees and what a unit costs here

Otay Water District serves eastern Chula Vista. A unit on the existing meter avoids a new connection; a new meter under 1 inch adds the County Water Authority's $6,683 capacity charge in 2026 ($5,617 from January 2027), plus Otay's own fees, which we could not confirm. The City's fee bulletin also lists a Salt Creek and Wolf Canyon sewer basin fee of $1,955 per EDU; whether it reaches an ADU on your lot is a question for Development Services.

Impact fees start at 750 sq ft and are prorated to the main house. East of I-805 the single-family base is about $57,700, including the $19,164 Eastern Transportation DIF and the $22,542 eastern park fee. Large homes help: an 800 sq ft unit next to a 3,000 sq ft San Miguel Ranch house would pay about 27%, roughly $15,400, if the City uses the single-family rate as its base. School fees of about $5.38 a square foot apply from 500 sq ft.

Model mids for a new detached unit east of the freeway run about $360,000 at 760 sq ft and $499,000 at 1,200 sq ft, before any slope work. A JADU carved from a spare bedroom costs far less, about $100,000 at 300 sq ft in the site's model, and a single-bay garage conversion lands between the two. HUD's FY2027 Small Area payment standards for 91914 are $3,410 for a one-bedroom and $4,120 for a two-bedroom, from a third-party mirror and set as voucher ceilings, not market rents. Compare options in the Chula Vista ADU cost calculator.