21 Brennan Ave, Waltham, MA 02451 Property Records

Middlesex County and Waltham City property record for 21 Brennan Ave, Waltham, MA 02451

Property Summary

Property Type	Single Family Home
Details	2 bd · 1.5 ba · 1,660 sqft · built 1850
Lot Size	0.536 acres (23,361 sqft)
Owner	2 Individual Names on File
Last Sale	$700,000 (Jul 2019)
Tax Bill	$9,015 (2026)
Deeds & Mortgages	Jul 2019 Sale & Mortgage Aug 2018 Line of Credit
Flood Zone	Zone X (minimal risk)
APN	`13764`

Property Details

APN / Parcel Number

Primary APN	`13764`
Alternative APN	`WALT M:005 B:005 L:0014`

Interior

Bedrooms	2 Beds
Full Baths	1.5 Baths
Half Baths	1 Half Bath
Total Rooms	5 Rooms
Stories	2 Stories
Building Area	1,660 sqft Living Area
Gross Area	2,878 sqft
Basement Area	641 sqft
Unfinished Basement	641 sqft
Fireplaces	1 Fireplace
Fireplace	Fireplace

Exterior

Year Built	Built 1850
Effective Year Built	Effective 1850
Architectural Style	Colonial
Exterior Material	Aluminum/Vinyl
Construction Type	Frame
Roof Type	Gable
Roof Material	Asphalt
Lot Area	23,361 sqft (0.536 acres)

Utilities, Heating & Cooling

Heating System	Hot Water
Heating Fuel	Oil

Location & Zoning

Account Number	13764
Street Address	21 BRENNAN AVE
City	WALTHAM
State	MA
Zip	02451-1304
Property Category	Residential
Property Type	Residential > Single Family > Home
Local Zoning Code	1
Legal Block	5
Legal Lot Number	14
Jurisdiction	WALTHAM MA
Township / Civil Division	WALTHAM
Census Block Group	2
Census Block	2001
Census Tract	368102

Owner

21 Brennan Ave is owned and occupied by two individuals who bought it in July 2019.

Source: Middlesex County and Waltham City records, as of October 20, 2026

Owner of Record	2 Individual Names on File
Mailing Address	21 BRENNAN AVE, WALTHAM, MA 02451-1304
Occupancy	Owner Occupied
Owner Type	Individual
Vesting	Husband and Wife

Owner names and exact recorded amounts are on file and can be viewed instantly on this page with a free 10-day trial.

Deeds, Mortgages & Sale History

Date	Document
Jul 12, 2019	Quit Claim Deed, Transfer · Stand-Alone First Mortgage LEADER BANK NA
Aug 21, 2018	Deed of Trust, Mortgage · Line of Credit CITIZENS BK/RI

Assessor's Deed Record

Deed Names	2 Names on Deed
Last Sale	Jul 12, 2019 · Amount on File
Deed Sale	Jul 12, 2019 · Amount on File
Prior Sale	Oct 17, 2002 · Amount on File
Deed Document Number	201998666
Deed Book / Page	72912 / 51
Prior Transfer Date	Jun 13, 2019
Prior Transfer Doc	72912-51
Record Updated	Oct 29, 2026

July 2019: Quit Claim Deed, Transfer

Document Type	Quit Claim Deed
Jurisdiction	WALTHAM MA
Recording Date	Jul 12, 2019
Property Address	21 BRENNAN AVE, WALTHAM, MA 02451-1304
Document Number	72912-51
Book / Page	72912 / 51
Instrument Date	Jun 13, 2019
Instrument	98666
Transaction Type	Transfer
Record Updated	May 12, 2021

Transaction

Amount	Amount on Record
Downpayment	Downpayment on Record
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	21 BRENNAN AVE, WALTHAM, MA 02451-1304

Mortgage

Document Number	98667
Date	Jul 12, 2019
Instrument	98667

Lender

Name	LEADER BANK NA
Type	Bank

Agreement

Type	Stand-Alone First Mortgage
Amount	Amount on Record

August 2018: Deed of Trust, Mortgage

Document Type	Deed of Trust
Jurisdiction	WALTHAM MA
Property Address	21 BRENNAN AVE, WALTHAM, MA 02451-1304
Document Number	71591-148
Instrument Date	Aug 21, 2018
Transaction Type	Mortgage
Record Updated	Sep 27, 2018

Transferred To (Grantee/Buyer)

Name	Verified Name
Address	21 BRENNAN AVE WALTHAM MA 024511304, WALTHAM, MA 02451-1304

Mortgage

Document Number	71591-148
Date	Sep 7, 2018
Book Page	071591/000148
Instrument	138752

Lender

Name	CITIZENS BK/RI
Type	Bank

Agreement

Type	Line of Credit
Amount	Amount on Record

Interest

Rate Type	Adjustable Rate

Tax Assessment & Valuation

The 2026 property tax bill for 21 Brennan Ave was $9,015, up 11.1% from the year before.

Source: Middlesex County and Waltham City assessment roll, as of April 14, 2026

Property Jurisdictions

Type	Name
State	Massachusetts
County	Middlesex County
Municipality	Waltham City
Unified School District	Waltham School District (PK - 12)

Tax Bill & Assessment History

Year	Tax Bill	Assessed Value	Assessed Market Value
2026	$9,015.00 (+11.08%)	$873,500 (+5.69%) Land $592,800 Building $280,700	$922,995 (-2.42%)
2025	$8,116.00 (+5.33%)	$826,500 (+3.4%) Land $565,800 Building $260,700	$945,915 (+6.39%)
2024	$7,705.00 (+1.77%)	$799,300 (+8.96%) Land $540,800 Building $258,500	$889,105
2023	$7,571.00	$733,600 Land $490,800 Building $242,800

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

Flood

FEMA maps place 21 Brennan Ave in Zone X, an area of minimal flood risk, though there have been 1 flood claim nearby since 1978.

Source: FEMA National Flood Hazard Layer, effective September 10, 2026 · OpenFEMA NFIP redacted claims and policies, as of September 2026

FEMA Flood Zone	Zone X minimal risk
Flood Insurance Requirement	Not required lenders may require it
Nearby Flood Policies	8 in force
Nearby Flood Claims	1 (1978)
Most Recent Claim	Feb 1978 · tidal / storm surge

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.

Wildfire

Wildfire risk around 21 Brennan Ave is low, with a 0.01% annual chance of wildfire.

Source: USDA Forest Service Wildfire Risk to Communities (2nd edition), as of 2024

Wildfire Risk	Low lower than 80% of the US · above 57% of Massachusetts
Wildfire Likelihood	0.01% annual chance
Exposure	None beyond ember reach

Values cover an area roughly 900 ft across, not the parcel itself; insurers use their own ratings.

Drinking Water

Source: EPA Safe Drinking Water Information System, as of September 2026

Water System	WALTHAM WATER DEPARTMENT serves 65,218 people · EPA ID MA3308000
Water Source	Purchased surface water from MWRA
Last State Inspection	Jun 2024
Lead	2 ppb (2025) action level 15 ppb

Violations Reported to EPA

Water Quality	None last 10 years
Treatment and Procedure	None last 10 years
Monitoring and Reporting	1 last 3 years

Results are for the whole water system, not water tested at this address; lead at the tap also depends on the building's own pipes.

Internet Providers

Source: FCC Broadband Data Collection, based on 192 locations within half a mile, as of December 31, 2025

Provider	Max Down / Up (Mbps)
Xfinity Cable	2,000 / 2,000
Astound Broadband Cable	1,500 / 50
Verizon Fiber · Fixed Wireless in parts of the area	980 / 880

May also be available: T-Mobile.

Nearby Properties on Brennan Ave

Nearby Streets

Search Property Records by Address or Parcel Number

Search by:

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