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    Property profile & analytics

    309 18th St Antioch, CA 94509-2403

    • Office buildings
    • 1,920 SF
    • 0.33 lot acres
    OFF-MARKET
    Value Estimations
    $370,000
    Show details
    Cap Rate Potential
    8.3%
    Office buildings
    Location Intelligence
    Property ID
    US10-1883083
    The Realmo ID is a unique identifier assigned to every property, incorporating country codes and precise geo-coordinates for 300x300-foot land blocks. It enables standardized data collection and seamless integration of disparate sources such as ownership, tax, title data and physical specifications. By aggregating current and historical records, the Realmo ID powers advanced analytics and delivers deep, verifiable insights for real estate professionals.

    Current Use by Public Records

    • Office buildings

    Property Details for 309 18th St

    Year built
    2009
    Lot size
    0.33 lot acres
    Property size
    1,920 SF
    Property type
    Office buildings
    APN
    065-152-050-4
    APU
    651520504

    Description

    This exceptional executive office building, located at 309 E 18th Street in Antioch, California (zip code 94509), presents a compelling investment opportunity. The property boasts a total of 2,600 square feet situated on a 0.33-acre lot. The building features approximately 2,000 square feet of office space and approximately 600 square feet of warehouse space, ideal for a variety of business needs. The office area includes four executive offices, a reception area, and a dedicated conference room, providing ample space for both individual work and collaborative efforts. Additional storage is available in a large shed located on the property. The property also benefits from a significant amount of yard space surrounding the building. Convenient highway access via Highway 4 ensures easy commuting and accessibility. The building is currently vacant with a 30-day notice period, offering immediate occupancy. Financing options are available, with up to 90% financing potentially attainable. This property is a rare find in Antioch, combining prime location, versatile space, and significant potential for return on investment. Do not disturb the tenant.

    Value Estimations

    based on Realmo’s proprietary methodology

    • AI approach

      Method
      Estimation
      ML approach
      $350,000

    • CAP approach

      CAP Return
      Estimation
      6%
      $490,000
      6.5%
      $450,000
      7%
      $420,000

    • Comparable approach

      Method
      Estimation
      AI Estimate
      $449,000
      Market price range: $129k - $449k

    Get a detailed, property-specific valuation — fast and free

    Location Insight

    • Map
    • Local Demand
    City
    Antioch
    County
    Contra Costa
    State
    California
    Longitude
    -121.799
    Latitude
    38.0053
    CBSA code
    41860
    CBSA name
    SAN FRANCISCO-OAKLAND-FREMONT, CA METROPOLITAN STATISTICAL AREA

    Property Tax & Assessments

    Tax date
    Tax Amount
    Assessed Land Value
    Assessed Improvement Value
    Total Assessed Value
    Applied Tax Rate
    Land Market Value
    Improvement Market Value
    Total Market Value
    2024
    $7,299
    $163,500
    $418,244
    $581,744
    -
    $0.00
    $0.00
    $0.00

    Comparable in this City

    • Value Estimation
      $640,000
      13,222 SF

      3731 Sunset Ln

      OFFICE BUILDING • 13,222 SF
      3731 Sunset Ln, Antioch, CA 94509-6127
      View Details
    • Value Estimation
      $330,000
      2,982 SF

      501 3rd St

      OFFICE BUILDING • 2,982 SF
      501 3rd St, Antioch, CA 94509-1275
      View Details
    • Value Estimation
      $120,000
      2,284 SF

      1011 A St

      OFFICE BUILDING • 2,284 SF
      1011 A St, Antioch, CA 94509-2323
      View Details
    • Value Estimation
      $295,000
      4,396 SF

      1105 Buchanan Rd

      OFFICE BUILDING • 4,396 SF
      1105 Buchanan Rd, Antioch, CA 94509-4212
      View Details
    • Value Estimation
      $290,000
      1,250 SF

      2830 Lone Tree Way

      OFFICE BUILDING • 1,250 SF
      2830 Lone Tree Way, Antioch, CA 94509-4922
      View Details
    • Value Estimation
      $320,000
      1,889 SF

      604 Madill St

      OFFICE BUILDING • 1,889 SF
      604 Madill St, Antioch, CA 94509-3526
      View Details

    Similar Nearby for Sale

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      Medical/Professional Office Campus For Sale

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      Medical/Professional Flex Office Building

      Medical/professional and flex office building in Antioch, California.
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    • $1,500,000
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      Downtown Antioch Owner/User Opportunity

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    • $1,899,000
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      Free Standing Office Building Investment

      High-quality, fully leased office building with income in place.
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    • Contact for pricing
      988 SF

      Antioch Office Suite - Great Location

      988 sq ft Office, Utilities Included
      320 St Unit A, Antioch, CA 94509
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    • Contact for pricing
      747 SF

      Antioch Office Suite: Prime Location

      Spacious office, great visibility, utilities included.
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      View Details

    Similar Nearby for Lease

    • Contact for pricing
      2,678 SF

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      2,678 SF vacant building adjacent to Sutter Delta Hospital.
      3741 Sunset Ln, Antioch, CA 94509
      View Details
    • $0.18 SF/Yr
      52,680 SF

      Retail, Medical & Office Space

      Lease retail, medical, and office spaces near Somersville Towne Center.
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    • $11 SF/Yr
      5,618 SF

      Downtown Antioch Retail/Office Space

      Retail and office spaces available in downtown Antioch.
      601 W 2Nd St, Antioch, CA 94509
      View Details
    • $990 /Mo
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      747 SF Office Suite For Rent

      Office suite for rent with utilities included in central location.
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      View Details
    • $12 SF/Yr
      62,240 SF

      Antioch Medical Office Park Suites

      Prime Antioch office space, multiple suites available.
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      View Details
    • $990 /Mo
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      Office Suite in Central Location

      747 sq ft office suite in a gated building.
      320 E 18Th St, Antioch, CA 94509
      View Details
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    Antioch, CA 94509-2403
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    Realmo Value Estimations

    Realmo estimates a property’s market value using a proprietary methodology that incorporates public data and user-submitted information. This cumulative value is generated by integrating a variety of conventional and innovative methods. 

    Disclaimer

    These figures are not official appraisals and should not be used as a substitute for a valuation performed by a licensed appraiser.
    Actual market value may differ due to factors not captured in the data. Estimates are offered for informational purposes only, and users should conduct independent research before making financial or investment decisions.
    By using this feature, you acknowledge that Realmo is not responsible for actions taken based on these estimates.

    AI approach

    Realmo AI Method estimates property value using machine learning models trained on millions of comparable listings, transactions, and market signals. It analyzes property features, location intelligence data, and current market dynamics to predict the most probable market value in real time.

    Realmo CapRate Calculation

    Realmo calculates the Capitalization Rate (Cap Rate) to help estimate a property's potential return on investment. The Cap Rate is a fundamental metric in commercial real estate that measures the relationship between a property's net operating income and its market value.

    How We Calculate Cap Rate

    Cap Rate Formula:
    Cap Rate (%) = (Net Operating Income / Property Value) × 100

    Net Operating Income (NOI) Formula:
    NOI = Area × Lease Rate × (1 - Vacancy Rate) × (1 - Operating Expense Ratio)

    Components

    Net Operating Income (NOI) represents the annual income a property generates after operating expenses:

    • Area: Building square footage from property records
    • Lease Rate: Annual $/sqft based on market data for the property type and geographic location
    • Vacancy Rate: Percentage of unoccupied space based on market data for the property type and location
    • Operating Expense Ratio: Operating costs as a percentage of income, varies by property type

    Property Value is derived from:

    • Recent sale price (if available)
    • Statistical models using comparable sales
    • AI-powered valuation estimates

    Example Calculation

    For a 100,000 sqft Office Building:

    • Lease Rate: $25.00/sqft/year (market data for Office in this area)
    • Vacancy Rate: 8% (market data for Office in this area)
    • Operating Expense Ratio: 35% (typical for Office properties)
    • Property Value: $15,000,000

    Step 1: Calculate NOI

    NOI = 100,000 × $25.00 × (1 - 0.08) × (1 - 0.35)
    NOI = 100,000 × $25.00 × 0.92 × 0.65
    NOI = $1,495,000/year

    Step 2: Calculate Cap Rate

    Cap Rate = ($1,495,000 / $15,000,000) × 100
    Cap Rate = 9.97%

    Property Type Considerations

    Net Operating Income calculations vary by property type due to different operating expense ratios:

    • Office: Higher expenses (30-40%) for HVAC, utilities, maintenance
    • Retail: Moderate expenses (25-35%) for common area maintenance
    • Industrial/Warehouse: Lower expenses (15-25%) for minimal tenant services
    • Multifamily: Moderate expenses (35-45%) including property management
    • Self-Storage: Lower expenses (25-35%) due to minimal maintenance

    Market lease rates and vacancy rates are specific to each property type and geographic location, reflecting local market conditions.

    Disclaimer

    These calculations are estimates for informational purposes only and should not be used as a substitute for professional financial analysis or appraisal.

    • Cap Rate calculations depend on market data that may change over time
    • Actual operating expenses, lease rates, and vacancy rates may differ from market averages
    • Individual property conditions, lease terms, and tenant quality significantly impact actual NOI
    • Property value estimates are approximations and not official appraisals
    • Cap rates vary widely by market, property condition, and investment risk profile

    Professional Guidance Recommended: Before making any investment or financial decisions, consult with licensed appraisers, commercial real estate brokers, and financial advisors who can evaluate your specific property and circumstances.
    By using this feature, you acknowledge that Realmo is not responsible for investment decisions or actions taken based on these estimates.

    Cap approach

    Capitalization Method calculates value based on estimated net operating income (NOI) and applying a market-based capitalization rate (cap rate), we estimate what a typical investor might be willing to pay for it.

    Comparable approach

    Comparable estimate is based on recent sales of similar nearby properties, adjusted for factors like size, condition, and location.

    Relative

    Relative property class coefficient uses factors that account for typical price differences between various asset types (e.g., retail vs. industrial) to provide a more accurate market-aligned estimate.

    Geo

    Comparable Sales Method, enhanced by Geo coefficients — location-based adjustment factors that reflect differences in price levels across neighborhoods, cities, or regions ensuring a more accurate, market-sensitive valuation.

    Stat Estimate

    This method estimates value based on actual market adjusted recent (~5 years) sales of comparable properties around by location and property type.

    • Ranges - area data calculated by industry standard IQR Outlier Removal Method
    • Range-from: 75% of all similar sales ($/sqft) are above this value
    • Range-to: 75% of all similar sales ($/sqft) are below this value
    AI Estimate

    This method estimates value based on AI market estimation of comparable properties around by location and property type.

    • Ranges - area data calculated by industry standard IQR Outlier Removal Method
    • Range-from: 75% of all estimations ($/sqft) are above this value
    • Range-to: 75% of all estimations ($/sqft) are below this value
    Alternative use

    Estimate considers the property’s potential value if used for a different purpose-based on zoning, demand, and market feasibility.

    More about this property
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