21 Porter St East Boston, MA 02128-2111
Individually Owned
Free & Clear
Estimated value (blended)
$1.22M
Range $1.09M – $1.34M (±10%)
Implied cap rate
4.80%
In-place · NOI ÷ last sale
Property ID
US38-1472034
Property profile
Verified
Property type
Medical Office Space
Use group
MEDICAL BUILDING
Year built
1910
Construction
BRICK
Total area
2,850 SF
Lot
0.03 ac (1,500 SF)
Zoning code
C
APN
EBOS W:01 P:05915 S:000
UPID
US38-1472034
Cap rate & NOI
Priority signal for investors
Implied cap rate, NOI & suggested price
Cap rate vs submarket · NOI estimate · 3 price anchors
Current use
Occupant on record · Public records
-
Clothing Store
Value estimations
Realmo proprietary · 4 methods
AI Approach
AI
$1.21M
CAP Approach
CAP
$890k
Comparable Approach
Comparable
by Request
Blend (final)
Blend
$1.22M
Owner & transaction history
since 2025
Last sale
$1.4M
5 recorded transactions
Zoning & alternative use
C · East Boston, MA
Comparables
6 recent transactions · within 1.5 miComparable in this city
6 recent transactions
Comparable in this City
Similar Nearby for Sale
Similar Nearby for Lease
Recent comparable sales
Sale price & price/SF · Sale date & distance · Adjustments & confidence
Value estimation
Instant AI valuation built from comps, income signals, and proprietary benchmarks. A defensible range, not a single guess.
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Unlock the complete Valuation workflow
Full NOI reconstruction, selected comps, alternative-use scenarios, data audit and PDF export.
Sensitivity value band
Source audit · 10 inputs
PDF export
Analytics Standard · 5 reports
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Summary
1
Valuation conclusion
Included free
Estimated market value
$1.22M
Value range
$1.09M – $1.34M
±10% around blend
Estimated value / SF
$426 / SF
Confidence
None
1 county-verified comps
Property data
88
Comparable evidence
10
$1.09M
blend $1.22M
$1.34M
Market-derived valuation under stabilized market assumptions. Desktop analysis. No physical inspection performed.
2
Subject property
Included free
GBA
2,850 SF
Lot area
0.03 ac
Year built
1910
Stories
2
APN
EBOS W:01 P:05915 S:000
Assessed value
$723,400
Annual tax
$18,280
3
Income approach: direct capitalization
Partial preview
Income approach indication
$890k
Direct capitalization · @ 6.5% CAP return
@ 6% CAP return
$965k
@ 6.5% CAP return
$890k
@ 7% CAP return
$825k
4
Sales comparison
Partial preview
Too few qualifying comparables for a sales-approach estimation.
5
Sensitivity & risk
Partial preview
Downside
−10%
Base
$1.22M
Upside
+10%
Bounds of the ±10% band vs the blend — never simulated scenarios.
6
Data & methodology
Included free
Building area
County record
Property tax
County record
Assessed value
County record
Zoning designation
Not available
Operating expenses
Not available
Market rent
Not available
Actual rent roll
Not available
Tenant leases
Not available
Physical condition
Not inspected
Conversion costs
Not available
Not analyzed due to unavailable source data: tenant leases, physical condition and capital
requirements were not available for this desktop analysis. Cost Approach excluded due to
availability of income evidence.
Automated valuation analysis, not a licensed appraisal. Figures are derived from public
records and proprietary models. Desktop analysis: no physical inspection, tenant leases or reported
property income. Verify with a licensed appraiser before transacting.
Cap rate
Cap rate calculated from real income and expense signals, benchmarked against sales of similar assets nearby.
17% off on annual
Unlock the complete Cap Rate workflow
Full market tables, editable assumptions, comparable evidence, saved work and exports.
9-scenario matrix
Comparable evidence · 1 sales
Market rates by use type
PDF export
Analytics Standard · 5 reports
from $99/month
from $99/month
Overview
Implied cap rate
4.80%
Implied, in-place cap rate for this medical office space
Estimated NOI ÷ last recorded sale. Refine with your own numbers in the full report.
Lower yield / higher price
Higher yield / lower price
5.0%
This property · 4.80%
9.0%
NOI (est.)
$98k *
Last sale · Jun 2022
$1.40M
* derived from a real price signal at a 7% cap
Price sensitivity
The rate is the decision lever; valuation is the consequence.
Test a cap rate
Implied value$2.04M
Move the market yield to see immediate price impact.
Value / SF
$716
Vs. selected
Base
Derivation
NOI ÷ cap
Arithmetic over the derived NOI * — not market scenario modeling.
NOI × cap matrix
Preview
Preview of 9 modeled outcomes.
NOI
4.30%4.80%5.30%
$88k
$2.05M
$1.84M
$1.66M
$98k
$2.28M
$2.04M
$1.85M
$108k
$2.51M
$2.25M
$2.03M
NOI sensitivity ±10% across the selected-rate band (±0.5 pp) — derivation of the NOI above.
Comparable evidence
Partial preview
Recorded sales nearby
1 found
None confidence · county-verified
Property tax & assessments
Tax year 2024Property tax & assessments
Tax year 2024
Tax billed
$18,280
Tax year 2024
Assessed value
$723,400
Assessed 2024
Previous assessed
$758,500
-4.6% YoY
Effective rate
2.53%
On assessed value
Assessed land
$218,900
Assessed improvement
$504,500
Automated cap rate analysis. Based on public records, market benchmarks and proprietary
models. Verify with a licensed professional before transacting.
Property description
Physical attributes from public recordsBuilding & lot
Public records
Property type
Medical Office Space
Use group
MEDICAL BUILDING
Status
Off-Market
Year built
1910
Construction
BRICK
Heating
NONE
Buildings
1
Stories
2
Units
2
Total area
2,850 SF
Lot
0.03 ac (1,500 SF)
Zoning code
C
APN
EBOS W:01 P:05915 S:000
UPID
US38-1472034
Jurisdiction
BOSTON
Metro division
BOSTON-QUINCY, MA METROPOLITAN DIVISION
Zoning & alternative use
C · East Boston, MAZoning C · permitted uses
C · East Boston, MA
Permitted & conditional uses
Allowed uses · Special-permit conditions · Prohibited uses
Building & site characteristics
From public records
Year built
1910
Construction
BRICK
Heating
NONE
Stories
2
Buildings
1
Units
2
Lot
0.03 ac
Zoning
The recorded zoning designation, what the district officially allows, and the municipal source it comes from.
Zoning designation
County-recorded code
C
Jurisdiction
East Boston, MA
Recorded code
C
Ownership Intelligence
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Ownership report
Owner identityResolved entity and name variants
Portfolio holdingsLinked properties and estimated value
Deal signalsSell-side activity worth following
Debt & historyRecorded loans and transaction history
Private report access
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Owner of record and activity signals are derived from public records and modeled classifications.
They do not confirm beneficial ownership or intent to transact.
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