Penngrove, CA Real Estate & Homes for Sale
By Matthew Martinez, Founder, CEO & Managing Broker, Diamond Real Estate Group. California DRE #01869679.
Penngrove is an unincorporated community of about 2,100 residents in southern Sonoma County, California, between Petaluma and Cotati, with village lots as small as 6,000 square feet surrounded by rural parcels and farmland. Redfin put the ZIP 94951 median at about $1.4 million for the three months ending August 2026, on very few sales. Sonoma County, not a city, sets the rules here, guided by the Penngrove Area Plan first adopted in 1984.
- County
- Sonoma County
- Government
- Unincorporated (county rules)
- ZIP code
- 94951
- Population
- 2,119 (ACS 2020–2024)
- Median sale price
- About $1.4M (3 months to Aug 2026, Redfin; few sales)
- Housing units
- 1,036 (ACS 2020–2024)
- Sewer
- Penngrove Sanitation Zone in the village; septic elsewhere
- Nearest SMART
- Cotati and Petaluma North stations
Penngrove homes for sale
Penngrove listings on the MLS are shown below. With only seven sales in August 2026 by Redfin’s count, it helps to watch Cotati, Rohnert Park and the rural land toward Petaluma at the same time; you can set that up with our property search.
What do homes in Penngrove sell for?
About $1.4M
ZIP 94951, 3 months ending August 2026, Redfin
7
August 2026, Redfin (15 a year earlier)
59
ATTOM, accessed October 2026
Treat any Penngrove median with caution. Redfin’s 94951 page reported a three-month median of about $1.4 million, 3.6% above a year earlier, but its own summary box showed a different figure, and seven sales in a month is too few for a stable number. The Census Bureau’s 2020–2024 survey puts the median value of owner-occupied homes at $1,196,000, well above the $815,500 countywide figure from the same survey.
| Measure | Figure | Period and source |
|---|---|---|
| Median sale price, ZIP 94951 | About $1.4 million (up 3.6%) | 3 months ending August 2026, Redfin |
| Median price per square foot | $683 (down 8.1%) | Redfin, accessed October 2026 |
| Average days on market | 57 (31 a year earlier) | Redfin, accessed October 2026 |
| Residential properties; sales in the past year | 1,502; 59 | ATTOM, accessed October 2026 |
| Average home size | 2,068 sq ft | ATTOM, accessed October 2026 |
| Median value of owner-occupied homes | $1,196,000 (± $81,270) | 2020–2024 ACS, Census Reporter |
| Sonoma County median sale price | $875,000 | September 2026, C.A.R. |
Because a village lot and a rural parcel of several acres can sell in the same month, we price Penngrove homes from comparable lots, not from the median: acreage, sewer or septic, public water or a well, outbuildings and road frontage. Petaluma and Cotati sales fill gaps when Penngrove has none. The Sonoma County market report follows the county trend.
Where is Penngrove, and who makes the rules?
Penngrove lies between Petaluma to the south and Cotati and Rohnert Park to the north, along Old Redwood Highway, Petaluma Hill Road and Adobe Road. It shares an origin with Cotati and Rohnert Park: all three sit on what was the 17,234-acre Rancho Cotate, held by the Page family from 1849 to 1929 (City of Cotati). Its ZIP code is 94951.
Penngrove is not part of Petaluma or Cotati. It is unincorporated, so Permit Sonoma handles zoning, building, well and septic permits, and the county’s own ordinances apply. Its local framework is the Penngrove Area Plan, adopted April 10, 1984 and modified in 1993 and 2008 (Penngrove Area Plan). The plan treats the land south of Ely Road as a community separator that forms a border for Petaluma, and it supports greenbelts between Penngrove and the cities around it. The county is now updating its General Plan, with adoption expected in 2028.
Lot sizes and the kinds of property in Penngrove
The Area Plan’s land-use categories explain why Penngrove homes vary so much. Its density rules, still the starting point before checking a parcel’s current zoning, run from village lots to farmland:
| Area Plan category | Density or minimum lot |
|---|---|
| Single Family Residential | 6,000 sq ft minimum north of Woodward Avenue; 10,000 sq ft south of it |
| Rural Residential, inside the sewer district | 2 acres per home |
| Rural Residential, outside the sewer district | 1.5 to 5 acres per home |
| Where no density is set | 1.0 acre with septic and public water; 1.5 acres with septic and a private well |
| Diverse Agriculture | 20 acres per home (10 acres south of East Railroad Avenue) |
Main Street is designated Limited Commercial, Old Redwood Highway is a major road where strip commercial development is discouraged, and Adobe Road, Petaluma Hill Road and Old Redwood Highway are scenic corridors. The plan also recommended a historic district for central Penngrove. ATTOM counts about 1,502 residential properties with an average size of 2,068 square feet.
The plan describes dairies, pasture and chicken ranches in its agricultural areas. Land on or within 300 feet of agricultural zoning can carry Sonoma County’s right-to-farm declaration, which is disclosed to buyers and warns of the noise, odors, dust, machinery and spraying that come with nearby farming. For horse and acreage properties, see our guide to ranch and acreage property in Sonoma County, and check Permit Sonoma’s Parcel Search for zoning and any Williamson Act contract.
Penngrove water, wells, sewer and septic
Water and wastewater are the first things to check on a Penngrove property, because the village and the rural land around it are served differently.
- Water: the Area Plan (1984, last modified 2008) says the Penngrove Water Company serves the Penngrove water district and that some lots rely on private wells. Confirm the source for each address with the seller and the water provider, and ask for recent water bills or the well records.
- Sewer: the Penngrove Sanitation Zone, run by Sonoma Water, covers 475 acres. It is a collection system only; sewage goes through the zone’s lift station into the City of Petaluma’s system for treatment (Sonoma Water).
- Septic: homes outside the sanitation zone use septic systems permitted by Permit Sonoma under the county’s onsite wastewater manual, version 9.0, approved in June 2026. Systems inside the Petaluma River’s advanced protection area (by default, within 600 feet of the river’s bank) are classed as Tier 3 under the county program, so ask where the system sits.
- Groundwater: the state has approved groundwater sustainability plans for both the Petaluma Valley and the Santa Rosa Plain basins. Ask the relevant groundwater agency which basin a well draws from and whether a fee applies.
Sonoma County does not require a septic inspection or well test when a property sells. On a Penngrove home outside the sewer and water systems, order both yourself during the contingency period: a septic inspection with pumping, and a well flow test with water-quality results.
New wells fall under the county well ordinance updated in 2023, which requires meters on most new non-residential wells and extra review in some areas. The county also reports that a court order on well permitting was temporarily stayed in March 2025, so check the current status before planning a new well. Our Sonoma County guide to wells and septic systems walks through those inspections in more detail.
Fire, flood and insurance checks
Lichau Creek runs northwest to southeast through Penngrove, and Willow Brook is a second creek corridor; the Area Plan called for floodplain zoning along both. If a parcel borders either creek, look it up on FEMA’s flood map and ask for any flood insurance history.
For fire, look up the address on CAL FIRE’s Fire Hazard Severity Zone map. If the parcel is in a High or Very High zone, California’s AB 38 rule requires the seller to provide a recent defensible-space inspection, or the buyer agrees in writing to complete the work within a year of closing. Request insurance quotes as soon as you’re in contract; on rural parcels the premium and the choice of carriers can change the numbers.
County rules on rentals, tenants and ADUs
Because Penngrove is outside the cities, county ordinances apply, and several differ from Petaluma’s next door.
- Vacation rentals: a whole-home rental of 30 days or less needs a county permit, a certified property manager, a vacation rental license and a transient occupancy tax account, and isn’t allowed in R1, R2 or R3 zoning, on Williamson Act land or in an ADU (Permit Sonoma). The county lodging tax is 12%. Our vacation rental guide explains the zones.
- Tenants: the county’s Residential Tenancy Protections Ordinance, adopted September 17, 2024, gives just-cause protection from the first day of a tenancy in unincorporated areas (County of Sonoma). Petaluma’s separate tenant ordinance doesn’t apply in Penngrove.
- Mobile homes: space rents in unincorporated parks are limited to 70% of the change in the Consumer Price Index, currently 2.66%.
- ADUs: since January 8, 2026, a single-family lot can have up to two ADUs plus a junior unit; a new detached ADU can reach 1,200 square feet. On septic, the system’s capacity for the extra unit has to be confirmed first. See our guide to building lots and ADUs.
- Transfer tax: only the county’s $1.10 per $1,000 applies. A home inside Petaluma’s city limits would also pay Petaluma’s $2.00 per $1,000.
Getting around from Penngrove
Penngrove has no SMART station. The closest are Cotati, at 980 East Cotati Avenue with a park-and-ride lot, and Petaluma North, at 320 Corona Road, which opened on January 10, 2025 and has free day-use parking (SMART). By road, the Area Plan names Old Redwood Highway as the area’s major arterial, with Adobe Road and Petaluma Hill Road as scenic corridors. The Census estimate of the mean commute for Penngrove workers is 35.2 minutes, longer than Cotati’s or Rohnert Park’s. Crane Creek Regional Park, 128 acres with 3.5 miles of trails east of Rohnert Park, has a 94951 address on Pressley Road.
Penngrove compared with nearby areas
| Area | Government | One verified difference |
|---|---|---|
| Penngrove | Unincorporated | ZIP 94951 median about $1.4 million on very few sales; county rules; sewer zone in the village, septic and wells outside it |
| Petaluma | City | East-side ZIP 94954 median $883,500 and west-side 94952 $1,085,000 (3 months to August 2026, Redfin); $2.00 per $1,000 city transfer tax; its own tenant ordinance |
| Cotati | City | ZIP 94931 median $759,671 (3 months to August 2026, Redfin); city water and sewer; its own SMART station |
| Rohnert Park | City | ZIP 94928 median $705,000 (3 months to August 2026, Redfin); new subdivisions at SOMO Village and the University District; whole-house short-term rentals not allowed |
How Diamond Real Estate Group helps Penngrove buyers
Most Penngrove purchases turn on the parcel rather than the house. Before you remove contingencies, we confirm the water source and sewer or septic status, order the septic and well inspections the county doesn’t require, check zoning, density and any Williamson Act contract on the county’s Parcel Search, look at creek frontage against the flood map, and price the home from sales of similar lots in Penngrove, Cotati and Petaluma.
- Licensed agents across Sonoma County, with DRE records linked, and agents who work in neighboring Petaluma.
- How to buy a home in Sonoma County, from pre-approval to closing.
If you own in Penngrove and are thinking of selling, start with a home valuation. Our Sonoma County real estate guide covers the rest of the county, and our buyer services page explains how we work.
Selling a home in Penngrove
Penngrove has no city hall, so Permit Sonoma holds the building, septic and well records for every parcel, village lot or farm. Pull the permit history for additions, barns and second units before you list. Buyers comparing a Penngrove house with one in Petaluma will ask which improvements carry county finals.
Transfer tax
The county recorder charges $0.55 per $500 of value, the same as $1.10 per $1,000, less any loan the buyer assumes. On a $1,400,000 sale that comes to $1,540. Petaluma’s extra $2.00 per $1,000 applies only inside its city limits, so it does not reach a Penngrove parcel; make sure the deed declaration marks the property as unincorporated. In Diamond’s North Bay markets the seller customarily pays the county tax, but it can be negotiated. Our transfer tax guide shows the arithmetic.
Water and wastewater records
Penngrove splits between the village, which has a Sonoma Water sanitation zone and a water company, and rural land on wells and septic. Tell buyers plainly which applies to your home and back it up with paperwork.
- Sewer or septic. In the sanitation zone, have recent sewer bills ready. On septic, gather the permit, pumping receipts and any inspection reports.
- Supplemental treatment. A septic system with a treatment unit needs a Permit Sonoma operating permit, renewed every year by June 30, with owner monitoring reports in March and October. The owner’s signed county acknowledgement requires telling the next owner, so put the permit and service-provider records in the disclosure package.
- Water source. Provide water company bills, or the well log and any flow and quality tests you have.
- Farm neighbors. If a right-to-farm declaration is recorded on the parcel, disclose it.
Fire zone and state items
Check the parcel’s fire hazard zone before listing. In a High or Very High zone, Civil Code 1102.19 requires defensible-space documentation from the past six months, or a signed agreement that the buyer will get it within a year of closing; see our AB 38 inspection guide. Every sale also needs your written smoke alarm statement, a water heater bracing certification and the Civil Code 1101.4 notice on noncompliant plumbing fixtures.
Because one Penngrove month can pair a village cottage with several acres, a median says little about your home; start with a Penngrove home valuation built from similar lots. Our Sonoma County seller guide covers timing and the full disclosure set.
Sources for this section: County of Sonoma Clerk-Recorder: Documentary transfer tax; Permit Sonoma: Operational Permit and Monitoring Program; Permit Sonoma: Form WLS-043, acknowledgement of operational permit requirement; Justia: California Civil Code section 1102.19; California Public Law: Health and Safety Code section 13113.8; California Public Law: Health and Safety Code section 19211; California Public Law: Civil Code section 1101.4.
Penngrove real estate FAQs
Where is Penngrove, California?
Penngrove is in southern Sonoma County, between Petaluma to the south and Cotati and Rohnert Park to the north. Old Redwood Highway, Petaluma Hill Road and Adobe Road are its main routes.
What county is Penngrove in, and is it a city?
Penngrove is in Sonoma County and is not a city. It’s unincorporated, so the County of Sonoma, through Permit Sonoma, handles planning and permits under the Penngrove Area Plan.
Which ZIP code covers Penngrove?
Penngrove’s ZIP code is 94951. Some properties east of Rohnert Park, such as Crane Creek Regional Park on Pressley Road, also carry 94951 addresses.
What is the median home price in Penngrove?
Redfin’s three-month median for ZIP 94951 was about $1.4 million through August 2026, but it rests on very few sales. The Census survey puts the median owner-occupied home value at $1,196,000; a specific home’s price depends mostly on lot size, water and sewer.
Is Penngrove part of Petaluma?
No. Penngrove is outside Petaluma’s city limits, and the county’s Area Plan keeps the land south of Ely Road as a community separator between them. Petaluma’s transfer tax and tenant ordinance don’t apply.
Do Penngrove homes have public water or wells?
Both exist. The county’s Area Plan says the Penngrove Water Company serves the Penngrove water district, while other lots rely on private wells. Confirm the source for each address.
Are Penngrove homes on sewer or septic?
The village is served by Sonoma Water’s Penngrove Sanitation Zone, whose sewage is treated through the City of Petaluma’s system. Homes outside the 475-acre zone use septic systems.
Does the county require a septic inspection when a Penngrove home sells?
No. Sonoma County has no point-of-sale septic or well requirement, so a buyer should order a septic inspection and a well test during escrow.
How big are lots in Penngrove?
Under the Area Plan, village lots start at 6,000 or 10,000 square feet, rural residential land runs 1.5 to 5 acres per home outside the sewer district, and agricultural land is planned at 20 acres per home. Current zoning on the parcel is what governs.
Can I keep animals or farm in Penngrove?
It depends on the parcel’s zoning, which sets what animals and farm uses are allowed, and parcels near farmland carry the county’s right-to-farm disclosure. Check the zoning on Permit Sonoma’s Parcel Search before you buy.
Can I rent a Penngrove home as a vacation rental?
Only with a county vacation rental permit, license and property manager, and only where zoning allows it; R1, R2 and R3 zones, Williamson Act land and ADUs are excluded. Stays of 30 days or less owe the county’s 12% lodging tax.
Does the SMART train stop in Penngrove?
No. The nearest stations are Cotati, at 980 East Cotati Avenue, and Petaluma North, at 320 Corona Road, which opened in January 2025.
Can I build an ADU on a Penngrove property?
Usually, under the county ADU ordinance in effect since January 8, 2026, which allows up to two ADUs and a junior unit on a single-family lot. On septic, confirm the system can serve the added unit before you plan around it.
Sources & notes
- Redfin: ZIP 94951 housing market (3 months ending August 2026), ATTOM: Penngrove property data and Census Reporter: Penngrove, ACS 2020–2024
- C.A.R.: September 2026 home sales and price report
- Permit Sonoma: Penngrove Area Plan (1984, modified 2008), vacation rentals, septic (OWTS) manual, well ordinance, ADUs and General Plan update
- Sonoma Water: Penngrove Sanitation Zone
- County of Sonoma: tenant protections, mobilehome rent stabilization, transient occupancy tax and documentary transfer tax
- Office of the State Fire Marshal: AB 38 guidance, SMART: stations, City of Cotati: Rancho Cotate history and Sonoma County Regional Parks: Crane Creek
Figures carry their dates where they appear, and we refresh market numbers every quarter. This is general information, not legal, tax or insurance advice; confirm the rules for a specific property with the agency named. Last reviewed October 2026 by Matthew Martinez.
Plan your next move
Share your preferred location, budget, property requirements and timing. We can help organize a focused search, arrange showings or discuss preparing a property for sale.
Local resource: Sonoma County community directory. Check official information for the address you are considering; area descriptions do not establish a property’s permitted uses.
