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    100 Borthwick Ave Portsmouth, NH 03801

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    For Lease
    Contact for pricing

    Prime Portsmouth Office, Flexible Suites Available

    Lot size:
    47,745 SF

    Property Features for 100 Borthwick Ave

    General Information

    Property type
    Office Properties & Spaces
    Lease Type
    Gross Lease
    RSF (Rentable sq. ft)
    47,745 SF
    Total Rate
    111405

    Building Details

    Year Built
    1978
    Stories
    2

    Spaces For Lease

    at 100 Borthwick Ave, Portsmouth, NH 03801 Contact us
    Unit Second Floor Suite 320

    $28 /Mo

    Size
    4,968 SF
    Contact us
    Unit Second Floor Suite 330

    $28 /Mo

    Size
    1,748 SF
    Contact us
    Unit Lower Level Suite 110

    $28 /Mo

    Size
    10,735 SF
    Contact us
    Unit Second Floor Suite 310

    $28 /Mo

    Size
    5,865 SF
    Contact us
    Unit First Floor Suite 230

    $28 /Mo

    Size
    6,484 SF
    Contact us
    Unit First Floor Suite 210

    $28 /Mo

    Size
    13,027 SF
    Contact us
    Show more

    We can help!

    Listing Contact
    Kent White
    Kent White

    Listing Agency: The Boulos Company Listing Agent: Kent White

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

    Learn more

    Property Insight Report

    Overview

    This exceptional two-story office building, located at 100 Borthwick Avenue in Portsmouth, New Hampshire, offers 47,745 square feet of premium executive office space. Currently, 42,827 square feet is available for lease, with flexible suite sizes ranging from a minimum of 1,748 square feet to a maximum contiguous space of 13,027 square feet. The building, constructed in 1978, sits on an expansive 8-acre lot and is zoned OR - Office Research, providing ample opportunity for a variety of businesses. The property boasts ample parking for tenants and employees, along with convenient elevator access for ease of movement between the two floors. The building is ideally situated in Portsmouth, NH, with the address being 100 Borthwick Ave, zip code 03801. This location offers excellent accessibility and visibility within Rockingham County. Multiple tenancy options are available, making this property suitable for businesses of various sizes and needs. Interested parties should inquire about the available spaces and lease terms. This is a rare opportunity to secure high-quality office space in a desirable Portsmouth location.
    Property Profile Insight Report Location Intelligence

    Current Use by Public Records

    Money Management International ... Law Firm

    Suggested Use

    Real Estate Agency Law Firm Building Supply Spa & Massage Center Dental Office Big Box & Wholesale Store Auto Repair Shop Hair Salon Nail Salon Hotel & Motel

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

    Location Insight

    • Map
    • Local Demand
    City
    Portsmouth
    County
    Rockingham
    State
    New Hampshire
    Longitude
    -70.7948231
    Latitude
    43.0595944

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    FAQs

    What type of property is this?
    Office Property / Space - Prime Portsmouth Office, Flexible Suites Available
    Where is this office property / space located?
    The property is located at 100 Borthwick Ave Portsmouth, NH.
    What is the lease rate?
    The lease rate is $28 SF/Yr.
    What are key features of this property?
    This property features: 47,745 SF two-story office building with 42,827 SF available for lease; suites from 1,748 SF to 13,027 SF contiguous.; Flexible suite layouts featuring private offices, open space, conference rooms, and kitchenettes.; Ample on-site parking.
    (603) 781-6546 Call to check price and availability
    Request Owner's contact information
    100 Borthwick Ave Portsmouth, NH 03801
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    Portsmouth, NH 03801
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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
    100 Borthwick Ave Portsmouth, NH 03801
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    We can help!
    Contact for Pricing
    Please call us for current price
    and status of this listing Kent White
    Kent White
    Real Estate License ID: 052480
    (603) 781-6546 (603) 427-1333
    Learn more
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