Folsom | Lots and Subdivisions
Folsom, California Lot Sizes and Subdivisions: Minimum Lots by Zone, Parcel Maps and Tentative Maps, Lot Line Adjustments, Hillside Lots, Parkland, and SB 9 and SB 684 Lot Splits
This page covers lot sizes and dividing land in Folsom, California. A lot is a piece of land with its own legal description; dividing one lot into two or more is a subdivision, and each new lot is recorded on a map. Folsom sets lot sizes zone by zone in Title 17 and the map process in Title 16, Subdivisions. Most lots must be 6,000 square feet or larger. Folsom's code has no chapter on SB 9 lot splits, so the state statute supplies those rules. The Folsom overview has the summary.
Folsom lots and maps in six facts
- A lot in the R-1-M, R-2, R-3, R-M and R-4 zones needs 6,000 square feet inside a block and 7,500 square feet on a corner. Source: Folsom Municipal Code 17.13.040 and 17.16.040
- R-1-ML lots need 10,000 square feet and R-1-L lots 14,500 square feet. Source: Folsom Municipal Code 17.12.040 and 17.11.040
- A tentative and final parcel map is required for "all divisions of land into 4 or less parcels," and a tentative and final map for 5 or more. Source: Folsom Municipal Code 16.12.020 and 16.12.030
- A tentative map approval expires 24 months after approval, and extensions may not exceed "a total of six years." Source: Folsom Municipal Code 16.16.110 and 16.16.120
- Under SB 9, both new parcels must be at least 1,200 square feet, and neither may be smaller than 40 percent of the original lot. Source: Government Code 66411.7
- The ADU chapter limits a parcel created by an SB 9 lot split to "no more than two units (including ADUs and JADUs)." Source: Folsom Municipal Code 17.105.120(A)(3)
Minimum Lot Sizes by Zone
Each residential chapter of Title 17 states the smallest lot that zone allows, its width and how much of it buildings may cover. Lot width is "the distance between side lot lines measured at the front yard building line." A corner lot is "a lot located at the junction of 2 or more intersecting streets," and "The shortest such street frontage constitutes the front of the lot." Corner lots need more area and width in most zones.
| Zone | Lot area | Lot width | Building coverage |
|---|---|---|---|
| R-1-L | 14,500 sq ft | 75 ft (75 ft corner) | 30 percent |
| R-1-ML | 10,000 sq ft | 60 ft (75 ft corner) | 35 percent |
| R-1-M | 6,000 sq ft (7,500 corner) | 60 ft (75 ft corner) | 35 percent |
| R-2 | 6,000 sq ft (7,500 corner) | 60 ft (75 ft corner) | 40 percent |
| R-3 | 6,000 sq ft (7,500 corner) | 60 ft (75 ft corner) | 50 percent |
| R-M | 6,000 sq ft (7,500 corner), plus 1,700 sq ft per home | 60 ft | 60 percent |
| R-4 | 6,000 sq ft (7,500 corner) | 60 ft (75 ft corner) | 60 percent |
| E-1 combining | Net average of 14,500 sq ft; average frontage 100 ft | See area | Base zone |
| E-2 combining | Net average of one-half acre; no lot under 20,000 sq ft; average frontage 125 ft | See area | Base zone |
| Historic residential area | 7,000 sq ft | 50 ft | 45 percent of the lot kept pervious |
| Mixed-use zones | Site of 0.5 acre | Not set | 10 percent landscape at least |
Sources: Folsom Municipal Code 17.11, 17.12, 17.13, 17.14, 17.16, 17.17, 17.18, 17.23.050, 17.52.540 and 17.56.
Building coverage is "the land area covered by all buildings on a lot, including all projections except eaves." In the R-M zone the lot must also hold 1,700 square feet for each home, so a 6,000 square foot R-M lot holds three homes. In the estate districts the rule applies to the average of all lots in a development, and "Lots or parcels having 2,500 square feet in excess of 1/2 acre shall not be considered in averaging the lot areas" in E-1.
Existing Lots and Lots That Are Too Small
Section 17.58.060 protects older lots: "Any lot of record existing prior to the date of adoption of the ordinance codified herein shall be considered a legal building site." A lot of record is a lot already shown on a recorded map or deed. Such a lot may be built on even when it is smaller than the zone now requires.
- Large lots. A lot "in one ownership having an area sufficient for more than one dwelling may be used and a building permit may be issued for such use," provided the owner who changes lot lines files a record of survey map, a map prepared by a surveyor, with the Planning Commission.
- Street frontage. "Every residential structure shall have frontage on a public street, or an access way which has been approved for residential access by the planning commission."
- Variances. Where strict lot size or yard rules cause "practical difficulties, unnecessary hardships," the Planning Commission may grant a variance under Chapter 17.62 after a public hearing. A variance cannot change the uses allowed.
- Planned developments. A planned development permit under Chapter 17.38 may vary "lot area and coverage," so lots inside a PD may be smaller than the table shows.
Which Map a Division Needs
Chapter 16.12 sets the map rules. "A tentative and final parcel map shall be required for all divisions of land into 4 or less parcels." For 5 or more parcels, or 5 or more condominiums, "A tentative and final map shall be required." A tentative map is the first drawing of the proposed lots, reviewed at a hearing; the final map is the survey document sent to the county recorder after approval. Both must be prepared by a registered civil engineer or licensed land surveyor.
| Process | Used for | Who decides | Time limits |
|---|---|---|---|
| Lot line adjustment | Moving a line between existing parcels, no new parcel | Planning director, after 10 days' notice to abutting owners | Appeal to the Planning Commission within 10 days |
| Tentative and final parcel map | 4 or fewer parcels | Planning Commission, at a public hearing; city engineer approves the final parcel map | Tentative map expires in 24 months |
| Tentative and final map | 5 or more parcels or condominiums | Planning Commission recommends; City Council decides; City Council approves the final map | Recommendation within 50 days of a complete application; expires in 24 months |
| Vesting tentative map | A map that fixes the rules in force on the date of application | Same bodies as the map it vests | Chapter 16.28 |
| SB 9 urban lot split | One parcel into two in a single-family zone | Staff, without a hearing, under Government Code 66411.7 | 60 days, then deemed approved |
| SB 684 / SB 1123 map | Up to 10 parcels and 10 homes on qualifying lots | Staff, without a hearing, under Government Code 66499.41 | 60 days, then deemed approved |
Sources: Folsom Municipal Code 16.12, 16.16, 16.20.090, 16.24 and 16.28; Government Code 66411.7 and 66499.41.
- Who reviews. Title 16 names the Planning Commission as the "Advisory agency," the body "that has the designated authority to approve, conditionally approve or disapprove maps." The community development department receives applications.
- Lot line adjustments. No map is needed when "No additional parcels or building sites are created" and the new parcels conform to Titles 17 and 14. The planning director decides after notice to abutting owners "At least 10 days prior," and the adjustment is recorded by deed or record of survey.
- Waivers. The Planning Commission may waive a parcel map for a few cases, among them "Construction of a condominium project on a single parcel." A certificate of compliance is then recorded instead.
- Exceptions. Section 16.04.050 lists divisions Title 16 does not reach, including the "construction, financing or leasing of dwelling units pursuant to Section 65852.1 or second units pursuant to Section 65852.2 of the Government Code." Those are section numbers from before SB 477 of 2024, which added the current ADU sections, such as 66315, to the Government Code.
Tentative Maps: Hearings, Deadlines and Expiration
For five or more parcels, Section 16.16.070 sends a complete application to a Planning Commission hearing. Notice is published and mailed "At least 10 days before the public hearing." The commission recommends approval, conditional approval or denial, and the department reports that recommendation "within 50 days after the tentative map application has been determined by the department to be complete." The City Council then holds its own hearing at "the next regular meeting" after it receives the recommendation, and "within 30 days thereafter."
- Denial grounds. The commission must recommend denial if the map is "inconsistent with the general plan, any applicable specific plan, or other applicable provisions of this code," or if "the site is not physically suitable for the type of development," among the other findings listed in Section 16.16.070.
- Appeals. Anyone adversely affected may appeal a Planning Commission action "within 10 days after the decision," in writing to the city clerk. The Council hears the appeal within 30 days.
- Expiration. "The approval or conditional approval of a tentative map shall expire 24 months from its approval by the city council." A parcel map approved by the Planning Commission expires 24 months from approval as well.
- Extensions. A request must be filed before the map expires. The Planning Commission hears it and the Council acts on it, and "The time at which the tentative map expires may be extended by the planning commission for a period not exceeding a total of six years." Ordinance 1317 of 2021 amended that subsection.
- Final map. The city engineer checks the final map against the tentative map, and the City Council "shall consider the final map for approval at its next regular meeting after the city clerk receives the" map.
Parkland Dedication
Section 16.32.040 makes a subdivider give land, pay a fee in place of land, or both, for parks. The standard is "5 acres of property for each 1,000 persons residing within this city." The formula multiplies the people expected per home by that standard. The table in the code lists 0.0146 acres per single-family home, 0.0114 per duplex home, 0.0097 per multifamily home and 0.0080 per mobile home.
- Small subdivisions. When a subdivision has "50 parcels or less," the subdivider pays a fee equal to the value of the land that would have been dedicated, unless the subdivider offers land and the Council accepts it.
- Count of homes. Where a zone allows more than one home per parcel, "the number of the proposed dwelling units in the area so zoned shall equal the maximum allowed under that zone." Homes "lawfully in place" before the map is filed are not counted.
- A mismatch in the code. The worked example in the section uses 2.77 persons and 0.0139 acres per single-family home, while the table beside it lists 2.92 persons and 0.0146 acres. Ask the City which figure it applies.
Hillside Lots
Chapter 14.33, the hillside development standards, applies to land shown on the City's hillside areas map, "Exhibit 'A'," which is "on file in the city clerk's office" and was not read for this guide. Any tentative map or parcel map there needs a preliminary grading plan reviewed by the Planning Commission at a hearing.
- Lot depth. "The average depth of any lot in hillside areas shall not exceed 3 times its width," unless the commission waives it.
- Slope. New lots need building sites "with existing slopes of twenty percent or less," unless the commission finds steeper sites necessary.
- Paving and roofs. Impervious surface, which means buildings and paving, "shall not exceed sixty percent of any lot in a hillside area." Every roof there must use "Class A roof materials," a fire rating class for roofing.
- Access. Each new lot needs "at least forty feet of frontage" on a street, driveways may not exceed a 15 percent grade without a commission finding, and "A maximum of four lots may share a single driveway."
SB 9 Urban Lot Splits
SB 9 lets an owner split one lot in a single-family zone into two, with staff approval and no hearing. The rules are in Government Code 66411.7, last amended effective June 30, 2026. The contents of Titles 16 and 17 list no SB 9 chapter, and a search of the saved chapters found Section 66411.7 only in the ADU chapter. The statute applies directly, and it binds a city "whether general law or chartered."
- Size. The two parcels must be "of approximately equal lot area provided that one parcel shall not be smaller than 40 percent of the lot area of the original parcel," and "both newly created parcels are no smaller than 1,200 square feet."
- Which lots. "The parcel is located within a single-family residential zone." Section 17.10.010 names R-1-L, R-1-ML and R-1-M as Folsom's single-family residence districts.
- Exclusions. A lot whose housing "has been occupied by a tenant in the last three years" is excluded, as is a split that requires demolition or alteration of "A contributing structure" in a historic district. Folsom has a historic district under Chapter 17.52.
- Owner occupancy. The applicant signs "an affidavit stating that the applicant intends to occupy one of the housing units as their principal residence for a minimum of three years from the date of the approval of the urban lot split."
- Two units per new lot. The statute says a city need not allow "more than two units on a parcel created through" a split. Folsom's ADU chapter adopts that cap: "no more than two units (including ADUs and JADUs) on a parcel created through a Senate Bill (SB) 9 (Chapter 162, Statues of 2021) lot split shall be allowed."
- Setbacks and size. A city "may require a setback of up to four feet from the side and rear lot lines," and may not apply standards that "would result in a unit size of less than 800 square feet."
- Deadline. An application "shall be considered and approved or denied within 60 days," or it "shall be deemed approved."
Small-Lot Maps Under SB 684 and SB 1123
Government Code 66499.41 requires a city to approve, "without discretionary review or a hearing," a map of "10 or fewer parcels" for a project of "10 or fewer residential units" on a lot "Zoned to allow multifamily residential dwelling use" of no more than five acres, or a vacant lot "zoned for single-family residential development" of no more than one and one-half acres, each "substantially surrounded by qualified urban uses." The decision is due "within 60 days." The version in force through December 31, 2026 was amended by SB 1090, effective September 30, 2026, and a new version starts on January 1, 2027. The Title 16 contents list no chapter on this law. See the SB 684 and SB 1123 page.
Limits of This Page
The City website answered 403, so the subdivision application forms, the fee schedule for maps, the hillside areas map, the zoning map and any City handout on SB 9 or SB 684 were not read. The code prints "An application for a land division or lot split shall be accompanied by a fee of $25" in Section 17.58.120, from Ordinance 323 of 1975; the fee resolutions that set today's map fees were not read, so that figure should not be used for a budget. Ask the Planning Division which forms and fees apply.
Best For
- ✓ R-1-M lots of 12,000 square feet or more, which can be split into two lots that each meet the 6,000 square foot minimum.
- ✓ Owner-occupied single-family lots with no tenant in three years, which qualify for an SB 9 split approved by staff.
- ✓ Vacant single-family lots of up to one and one-half acres, which may use the SB 1123 map path for up to 10 homes.
Usually Fails When
- ✕ A lot sits in a hillside area and the grading plan or the 20 percent slope rule was not planned for.
- ✕ A map budget leaves out the parkland fee or uses the 1975 fee printed in Section 17.58.120.
- ✕ An SB 9 split is planned on a lot rented in the last three years.
What To Verify Before Spending Money
- → Whether the lot is inside a planned development, an estate district or the hillside areas map.
- → The current map application fees and parkland in-lieu fee, from the City's fee resolution.
- → Which form and review the City uses for SB 9 and SB 684 applications.
Where to Go Next
Related on VanPlex: the Folsom overview, the California SB 9 page and the SB 684 and SB 1123 page.
Frequently Asked Questions
What is the smallest lot allowed in Folsom, California?
Can I split my lot in Folsom?
Does Folsom have its own SB 9 ordinance?
How long does a Folsom tentative map approval last?
Who approves a subdivision map in Folsom?
What is a lot line adjustment in Folsom?
How much parkland must a Folsom subdivision give?
Are there special lot rules in the Folsom hills?
What lot size does an SB 9 split need in Folsom?
Can I build 10 homes on a small Folsom lot under SB 684?
Can I still build on an older small lot in Folsom?
Official sources (checked October 2026)
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