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    21 Custom House St Boston, MA

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    Office space with fitness center and conference center in Boston.

    Type:OFFICE
    Property size:
    2,731 SF
    Lot size:
    0.25 Acres
    Added:
    May 15, 2025
    Days on Market:
    351
    Last Refresh:
    Apr 5 at 9:46 pm

    Property Features for 21 Custom House St

    General Information

    Standard status
    Active
    Size
    2,731 SF
    Lot size
    0.25 Acres
    Property subtype
    OFFICE

    Spaces For Lease

    at 21 Custom House St Contact us

    We can help!

    Listing Contact
    David Martel
    David Martel

    Listing agent David Martel

    Listing office Newmark | Boston

    Listing date May 15, 2025

    Source Moodyscre

    Displayed information is deemed reliable but is not guaranteed and should be independently verified.

    All listing content including descriptions, pricing, images are the copyrighted material of Newmark | Boston

    Overview

    Premier Office Space with Amenities

    Located at 21 Custom House Street, this office space offers a premier address for business. The property includes access to an upcoming exclusive amenity space designed to cater to professional and personal needs. A state-of-the-art fitness center is planned for tenants. A new conference center will provide a sophisticated space to host meetings, conferences, and events. Parking garages with 24/7 security are available at both 20 and 21 Custom House Street.
    Property Profile Insight Report Location Intelligence

    Current Use by Public Records

    Smile Design Boston Dental Office Carol R Johnson ... Landscaping G F K ... Business Management Consultant Dr. Christine Lo, ... Dental Office EDENS - Boston Construction Company

    Suggested Use

    Restaurant Real Estate Agency Spa & Massage Center Hair Salon Dental Office Nail Salon Food Market Grocery & Convenience Store Daycare Center Pharmacy

    Zoning and permitted uses should be independently verified with local authorities.

    Location Insight

    • Map
    • Local Demand
    City
    Boston
    County
    Suffolk
    State
    Massachusetts
    Longitude
    -71.0527
    Latitude
    42.3581

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    FAQs

    What type of property is this?
    Office units - Office space with fitness center and conference center in Boston.
    Where is this office units located?
    The property is located at 21 Custom House St Boston, MA.
    What are key features of this property?
    This property features: Premier business address in the heart of the city.; Exclusive tenant‑only amenity space coming soon.; State‑of‑the‑art fitness center for tenants.
    (617) 863-8090 Call to check price and availability
    We can help!
    Contact for Pricing
    Please call us for current price
    and status of this listing David Martel
    David Martel
    Learn More
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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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