423 Walnut St, Brookline, MA 02445 Property Records

Norfolk County and Brookline Town property record for 423 Walnut St, Brookline, MA 02445 · Last verified July 2026

Property Summary

Property Type	Single Family Home
Details	7 bd · 2.5 ba · 4,466 sqft · built 1909
Lot Size	0.295 acres (12,833 sqft)
Owner	2 Individual Names on File
Last Sale	$3,860,000 (May 2025)
Tax Bill	$30,831 (2025)
Deeds & Mortgages	Feb 2026 Mortgage May 2025 Sale & Refinance + 2 more
Flood Zone	Zone X (minimal risk)
APN	`12216031`

Property Details

APN / Parcel Number

Primary APN	`12216031`
Alternative APN	`BROO B:324 L:0006 S:0000`

Interior

Bedrooms	7 Beds
Full Baths	2.5 Baths
Half Baths	1 Half Bath
Total Rooms	12 Rooms
Stories	3 Stories
Building Area	4,466 sqft Living Area
Gross Area	8,058 sqft
Basement Area	1,426 sqft
Unfinished Basement	1,426 sqft
Fireplaces	1 Fireplace
Fireplace	Fireplace

Exterior

Year Built	Built 1909
Effective Year Built	Effective 1971
Architectural Style	Colonial
Exterior Material	Aluminum/Vinyl
Construction Type	Frame
Roof Type	Hip
Roof Material	Slate
Lot Area	12,833 sqft (0.295 acres)

Utilities, Heating & Cooling

Cooling System	HVAC
Heating System	Forced Air with A/C
Heating Fuel	Gas

Location & Zoning

Account Number	12216031
Street Address	423 WALNUT ST
City	BROOKLINE
State	MA
Zip	02445-5917
Property Category	Residential
Property Type	Residential > Single Family > Home
Legal Block	324
Legal Lot Number	6
Jurisdiction	BROOKLINE MA
Township / Civil Division	BROOKLINE
Census Block Group	1
Census Block	1002
Census Tract	401100

Owner

Source: Norfolk County and Brookline Town records · APN 12216031

Assessment roll updated April 14, 2026 · Last verified July 2026

Owner names and exact recorded amounts shown locked on this page are available instantly with a free trial.

Owner of Record	2 Individual Names on File
Mailing Address	423 WALNUT ST, BROOKLINE, MA 02445-5917
Occupancy	Owner Occupied
Owner Type	Individual
Vesting	Tenants by the Entirety

Deeds, Mortgages & Sale History

Date	Document
Feb 09, 2026	Deed of Trust, Mortgage · Conventional Mortgage CITIZENS BANK
May 09, 2025	Quit Claim Deed, Transfer · Stand-Alone Refinance STEPHEN MARTIROS
Feb 27, 2019	Deed of Trust, Mortgage · Line of Credit CENTURY BANK & TRUST
Apr 12, 2019	Quit Claim Deed, Transfer · Stand-Alone First Mortgage ENVISION BANK

Assessor's Deed Record

Deed Names	2 Verified Names on Deed
Last Sale	May 09, 2025 · Amount on Record
Deed Sale	May 09, 2025 · Amount on Record
Prior Sale	Apr 12, 2019 · Amount on Record
Deed Book / Page	42390 / 455
Record Updated	Sep 20, 2026

February 2026: Deed of Trust, Mortgage

Document Type	Deed of Trust
Jurisdiction	BROOKLINE MA
Property Address	423 WALNUT ST, BROOKLINE, MA 02445-5917
Transaction Type	Mortgage
Record Updated	Mar 04, 2026

Transferred To (Grantee/Buyer)

Name	Verified Name

Mortgage

Document Number	042923-285
Date	Feb 09, 2026
Book Page	42923/285
Instrument	8279

Lender

Name	CITIZENS BANK
Type	Bank

Agreement

Type	Conventional Mortgage
Amount	Amount Recorded
Term	361 Months
Due	Mar 01, 2056

Interest

Rate Type	Adjustable Rate
Rate	5.63%
Type Change Date	Mar 01, 2033
Index	1-Month LIBOR

May 2025: Quit Claim Deed, Transfer

Document Type	Quit Claim Deed
Jurisdiction	BROOKLINE MA
Recording Date	May 09, 2025
Property Address	423 WALNUT ST, BROOKLINE, MA 02445-5917
Document Number	042390-455
Book / Page	42390 / 455
Instrument Date	May 05, 2025
Instrument	29067
Transaction Type	Transfer
Record Updated	Nov 19, 2025

Transaction

Amount	Amount Recorded
Downpayment	Downpayment on File
Loan-to-Value (LTV)	LTV on Record
Tax	$0.00
Amount Accuracy	Full Amount Stated
Additional	Arm's Length

Transferred From (Grantor/Seller)

Name	Verified Name

Transferred To (Grantee/Buyer)

Name	Verified Name
Relationship	Tenants by the Entirety
Address	423 WALNUT ST, BROOKLINE, MA 02445-5917

Mortgage

Document Number	0000029148
Date	May 09, 2025
Instrument	29148

Lender

Name	STEPHEN MARTIROS

Agreement

Type	Stand-Alone Refinance
Amount	Amount Recorded
Term	361 Months
Due	Jun 01, 2055

February 2019: Deed of Trust, Mortgage

Document Type	Deed of Trust
Jurisdiction	BROOKLINE MA
Property Address	423 WALNUT ST, BROOKLINE, MA 02445-5917
Transaction Type	Mortgage
Record Updated	Mar 22, 2021

Transferred To (Grantee/Buyer)

Name	Verified Name

Mortgage

Document Number	36632-233
Date	Feb 27, 2019
Book Page	36632/233
Instrument	13937

Lender

Name	CENTURY BANK & TRUST
Type	Bank

Agreement

Type	Line of Credit
Amount	Amount Recorded
Term	241 Months
Due	Mar 01, 2039

April 2019: Quit Claim Deed, Transfer

Document Type	Quit Claim Deed
Jurisdiction	BROOKLINE MA
Recording Date	Apr 12, 2019
Property Address	423 WALNUT ST, BROOKLINE, MA 02445-5917
Document Number	36723-77
Book / Page	36723 / 77
Instrument Date	Apr 12, 2019
Instrument	26708
Transaction Type	Transfer
Record Updated	May 12, 2021

Transaction

Amount	Amount Recorded
Downpayment	Downpayment on File
Loan-to-Value (LTV)	LTV on Record
Tax	$0.00
Amount Accuracy	Full Amount Stated
Additional	Arm's Length

Transferred From (Grantor/Seller)

Name	Verified Name

Transferred To (Grantee/Buyer)

Name	Verified Name
Address	423 WALNUT ST, BROOKLINE, MA 02445-5917

Mortgage

Document Number	26709
Date	Apr 12, 2019
Instrument	26709

Lender

Name	ENVISION BANK

Agreement

Type	Stand-Alone First Mortgage
Amount	Amount Recorded

Tax Assessment & Valuation

Source: Norfolk County and Brookline Town records · Assessment roll updated April 14, 2026 · Last verified July 2026

Property Jurisdictions

Type	Name
State	Massachusetts
County	Norfolk County
County Subdivision	Brookline Town
Unified School District	Brookline School District (PK - 12)

Tax Bill & Assessment History

Assessed value and assessed market value are set for property tax purposes and are not market price estimates.

Year	Tax Bill	Assessed Value	Assessed Market Value
2025	$30,831.00 (+4.91%)	$3,123,700 (+3.84%) Land $1,394,400 Building $1,729,300	$3,645,245 (+12.22%)
2024	$29,389.00 (+7%)	$3,008,100 (+9.19%) Land $1,340,700 Building $1,667,400	$3,248,240
2023	$27,467.00	$2,755,000 Land $1,117,400 Building $1,637,600

Flood & Wildfire

Source: FEMA National Flood Hazard Layer, Norfolk County (25021C), updated May 26, 2026 · FEMA OpenFEMA NFIP redacted claims and policies, census block group 250214011001, refreshed September 2026 · USDA Forest Service Wildfire Risk to Communities, 2nd edition (2024), fuels as of 2020 · Last verified October 2026

Flood

FEMA Flood Zone	Zone X
Special Flood Hazard Area	No
Flood Hazard	Minimal
500-Year Floodplain	No
Nearest Special Flood Hazard Area	Zone A, within 500 ft
Nearby Flood Policies	9 in force
Nearby Flood Claims	2 (2014)
Claims Outside the SFHA	2 of 2
Most Recent Claim	Dec 2014, rainfall accumulation

Wildfire

Wildfire Risk	Not rated no burnable land in reach
Wildfire Likelihood	Negligible
Exposure	None beyond ember reach

Values are read at the parcel center point; flood claims are located to the census block group, not this parcel; lenders make the official flood determination.

Historic Designation

Source: NPS National Register of Historic Places · August 1, 2026 release · Last verified October 2026

Historic District	Within the Brookline Town Green Historic District listed 1980 · 64 contributing resources · NRIS 80000650

Federal listing alone does not restrict alterations; local historic district rules, which this data does not cover, may apply.

Internet Providers

Source: FCC Broadband Data Collection, availability as of December 31, 2025 · Published October 2026 · based on 160 locations within about half a mile of this property

Provider	Technology	Download / Upload (Mbps)
Xfinity	Cable	2,000 / 2,000
Radiate Holdings	Cable	1,500 / 50
T-Mobile USA	Fixed Wireless	100 / 20

May also be available at this address: Verizon, Starry. Availability varies by address; speeds are provider-advertised maximums, not measured.

Mobile Coverage

5G and 4G LTE

Nearby Properties on Walnut St

Nearby Streets

Search Property Records by Address or Parcel Number

Search by:

By searching, you agree to: Terms • Privacy • Disclosures