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    Downtown Third-Floor Office Suite Title is generated by Realmo AI

    159 Middle Street, Portsmouth, NH 03801

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    COMMERCIAL - Portsmouth, NH

    Added:
    Feb 5, 2026
    Days on Market:
    119
    Last Refresh:
    Jun 4 at 8:06 pm

    Property Features for 159 Middle Street

    General Information

    Property type
    Commercial Lease
    Property subtype
    Other
    Zoning
    Business
    Standard status
    Active

    Utilities

    Sewer type
    Public Sewer
    Water source
    Public

    Building Details

    Year built
    1850

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    Listing Contact
    John Samonas

    Listing agent John Samonas

    Listing office Samonas Realty, LLC 111 Bow Street, Portsmouth, NH

    Listing date Feb 5, 2026

    MLS# 5075877

    Copyright © 2026 PrimeMLS. All rights reserved. All information provided by the listing agent/broker is deemed reliable but is not guaranteed and should be independently verified.

    HighLights

    • Downtown Portsmouth office for lease within walking distance to all activities
    • Third‑floor walk‑up space
    • Includes heat and electric
    • Includes cleaning of common areas and parking
    • Kitchenette area in suite
    • Public water and public sewer

    Overview

    This downtown Portsmouth office suite is located on the third floor and is accessed via a walk-up. The offering includes heat and electric, along with cleaning of common areas. A kitchenette area is included for everyday convenience, and the space is supported by parking for staff or clients.

    The property is in a classic Portsmouth building featuring authentic woodwork and trim details. The location is described as within walking distance to downtown activities, positioning the suite for tenants seeking a walkable setting.

    This suite is a practical fit for professional users who want a compact, move-in-ready office arrangement. With utilities and common-area cleaning included, it offers straightforward operating terms for day-to-day occupancy. The combination of kitchenette convenience, parking availability, and an established historic-style building may be particularly well-suited for small teams serving customers locally.
    Property Profile Location Intelligence

    Current Use by Public Records

    Mintleaf Marketing Advertising Agency Upton & Hatfield, LLP Law Firm

    Suggested Use

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

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

    Location Insight

    • Map
    • Local Demand
    City
    Portsmouth
    County
    Strafford
    State
    New Hampshire
    Longitude
    -70.760937
    Latitude
    43.0735442

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    FAQs

    What type of property is this?
    Office units - Third-floor walk-up office suite with heat, electric, and common-area cleaning included, plus parking and a kitchenette.
    Where is this office units located?
    The property is located at 159 Middle Street Portsmouth, NH.
    What are key features of this property?
    This property features: Downtown Portsmouth office for lease within walking distance to all activities; Third‑floor walk‑up space; Includes heat and electric
    (603) 319-8100
    We can help!
    Listing Contact
    John Samonas
    Request Owner's contact information
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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.

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