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Single Family ResidenceResidential
$8,788,474$1,913 / ft²
TopHap EstimateOur estimate of what this home would sell for today, based on nearby sales, the home's size and features, and local price trends. It is a starting point, not an appraisal.· confidence 85How well the pricing models agreed with each other on this home. Higher means the estimate rests on stronger, more consistent data.· as of Sep 24, 2026
Last sold for $6,800,000 on Apr 15, 2022

321 SUMMIT AVE

MILL VALLEY, CA 94941
5
Beds
4.5
Baths
4,595 ft²
Living AreaTotal finished area of the structures, from county records. Some counties include shared space like hallways or a building gym, so it may not match a listing.
0.6 ac
Lot SizeThe size of the land the home sits on, from county records.
1935
Year BuiltThe year the home was originally built, according to county records.
2
ParkingThe number of parking spaces on the property, including the garage.

Valuation

$8.8M
$7.5M low$10M high
Last SaleThe most recent sale price and date from the recorded deed. Transfers between family members or companies may not reflect market value.$6,800,000 · Apr 15, 2022

Tax & Assessment

Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$86,500 (2025)
Assessed ValueThe value the county assigns to this home to calculate property tax. It is often lower than what the home would sell for.$7,418,822 (2026)
Assessed LandThe share of the county's assessed value that comes from the land itself, not the buildings.$4,437,922
Assessed ImprovementsThe share of the county's assessed value that comes from the buildings and other structures on the land.$2,980,900
Previous AssessedThe county's assessed value from the year before, useful for seeing how the assessment changed.$7,273,382

Property Facts

Property TypeThe broad category the county puts this property in, such as residential or commercial.Single Family Residence
StyleThe architectural style of the home, such as ranch or colonial.Contemporary
CountyMARIN
Effective Year BuiltAn adjusted build year that accounts for condition and major remodels. A big renovation can make a home count as newer than it is.2006
Lot (acres)The size of the land the home sits on, from county records.0.60
HeatingThe type of heating system in the home.Central
FireplaceWhether the home has a fireplace, and what kind.Yes
PoolWhether the property has a pool, and what kind, such as in-ground.No
FeaturesExtra features found in county records. Records are not complete everywhere, so a missing feature does not always mean the home lacks it.Deck · 440 ft²Patio · 440 ft²

Transaction History(12)

Sales and refinances filed with the county for this home. Not every transfer is a normal sale, so check the type before comparing prices.

Assigned SchoolsThe public schools this address is zoned for. Boundaries change, so confirm with the district before you count on it.

E
Old Mill Elementary SchoolA+
Elementary · Grades KG–5 · 0.3 mi
M
Mill Valley Middle SchoolA+
Middle · Grades 6–8 · 1.7 mi
H
Tamalpais High SchoolA
High · Grades 9–12 · 1.9 mi

District: Mill Valley Elementary School District

Neighborhood · ZIP 94941These are comparison scores, not percentages. 100 equals the national average, so 150 means about 50% above average.

CrimeLocal crime compared with the rest of the country, where 100 is average. It reflects things like population density, income, and how crime gets reported.91
Air pollutionOverall air pollution compared with the rest of the country, where 100 is average. Lower is cleaner.84
EarthquakeEarthquake risk and likely building damage compared with the rest of the country, where 100 is average. Scores can run far above 100.439

Index scale: 100 = US average (tick). Lower is better.

Homes occupiedThe share of homes here that someone lives in. The rest sit empty, including vacation and for-sale homes.93%
Bachelor's or higherThe share of adults 25 and older whose highest degree is a bachelor's degree.37%
Poverty rateThe share of people whose household income falls below the federal poverty line, which varies by family size.5.3%
UnemploymentThe share of men 16 and older who are out of work and actively looking. Only men are counted in this figure.1.1%
PopulationHow many people live in this area.30,767
DensityPeople per square mile. Higher numbers mean a more crowded, urban area.1,462 / mi²
Median incomeThe middle household income here — half of households earn more, half earn less.$194,124
Average incomeThe average household income. It runs higher than the median when a few high earners pull it up.$248,795
Average tempThe average temperature here across a full year.57°F
Annual precipHow much rain and melted snow falls here in a typical year.42 in
SunshineThe share of daylight hours that get direct sun in a typical year, counting cloud cover.78%

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Data by ATTOM. Valuations are automated estimates, not appraisals. Photos from Google Street View and may not depict the current property state.

How this home compares

321 Summit Ave measured against every home in its neighborhood, its ZIP code and its county, using county assessor records refreshed nightly. A home can stand out in one of those areas and look ordinary in another, because each one holds a different mix of homes.

  • Among the most valuable homes in Mill Valley 94941
  • Costs more per square foot than 98% of homes in Mill Valley 94941
  • Bigger than 98% of homes in Mill Valley 94941
  • Has a bigger lot than 92% of homes in Mill Valley 94941
  • Older than 88% of homes in Marin County

What homes are worth in Mill Valley 94941

Each bar is how many homes fall in that price range. The marker is this home.

This home
$782K$5.6M

This home is worth more than almost all homes in Mill Valley 94941.

How it measures up in Mill Valley 94941

The dot is this home. The mark in the middle is the typical home in Mill Valley 94941.

Estimated value$8,788,474
CheaperTypical $2,060,743Pricier

Pricier than almost all homes nearby

Price per ft²$1913
CheaperTypical $1048Pricier

Pricier than 98% of homes nearby

Living area4,595 ft²
SmallerTypical 1,964 ft²Bigger

Bigger than 98% of homes nearby

Lot size0.6 ac
SmallerTypical 0.19 acBigger

Bigger than 92% of homes nearby

Year built1935
OlderTypical 1959Newer

Newer than 16% of homes nearby

How 321 Summit Ave ranks against every home in each area.
MeasureThis homeCascade CanyonMill Valley 94941Marin County
Estimated valuepricier than$8,788,47498% of homesalmost all homesalmost all homes
Price per ft²pricier than$191396% of homes98% of homes98% of homes
Living areabigger than4,595 ft²94% of homes98% of homes97% of homes
Lot sizebigger than0.6 ac77% of homes92% of homes89% of homes
Year builtnewer than193531% of homes16% of homes12% of homes

About 321 Summit Ave

How much is 321 Summit Ave, Mill Valley, CA worth?

The TopHap Estimate for 321 Summit Ave, Mill Valley, CA is $8,788,474 as of Sep 24, 2026. The likely range is $7,471,389 to $9,999,999. The estimate is modelled from recorded sales, assessments and the property's own characteristics — it is not an appraisal.

When did 321 Summit Ave, Mill Valley, CA last sell?

321 Summit Ave, Mill Valley, CA last sold on Apr 15, 2022 for $6,800,000, according to the county's recorded deed. TopHap holds 9 recorded sales for this parcel.

How big is 321 Summit Ave, Mill Valley, CA?

321 Summit Ave, Mill Valley, CA has 5 bedrooms, 4.5 bathrooms, 4,595 square feet of living space and a 0.60-acre lot.

When was 321 Summit Ave, Mill Valley, CA built?

321 Summit Ave, Mill Valley, CA was built in 1935, making it 91 years old. It is a contemporary home.

What schools serve 321 Summit Ave, Mill Valley, CA?

321 Summit Ave, Mill Valley, CA is assigned to Old Mill Elementary School (elementary), rated A+; Mill Valley Middle School (middle), rated A+; Tamalpais High School (high), rated A. All sit in Mill Valley Elementary School District. Attendance boundaries change — confirm with the district before relying on an assignment.

How does 321 Summit Ave, Mill Valley, CA compare to other homes in Mill Valley 94941?

Among the 10,554 homes in Mill Valley 94941, it is worth more than almost all of them ($8,788,474 against a typical $2,060,743), its price per square foot is higher than 98% of them ($1913 against a typical $1048), it is bigger than 98% of them (4,595 ft² against a typical 1,964 ft²), its lot is bigger than 92% of them (0.6 ac against a typical 0.19 ac) and it is newer than 16% of them (1935 against a typical 1959). Measured against all of Marin County, it is worth more than almost all homes there. These shares are recounted nightly from the full county assessor record for each area, not from active listings.

What are the property taxes on 321 Summit Ave, Mill Valley, CA?

The 2025 property tax bill for 321 Summit Ave, Mill Valley, CA was $86,500. The county assessed it at $7,418,822.

More homes on Summit Ave

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More homes in Mill Valley 94941

Assigned schools

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