Middlesex County and Waltham City property record for 100 5th Ave, Waltham, MA 02451
| Property Type | Office Building |
|---|---|
| Details | 3 bd · 9 ba · 95,981 sqft · built 1982 |
| Lot Size | 4.44 acres (193,637 sqft) |
| Owner | 2 Company Names on File |
| Tax Bill | $697,860 (2026) |
| Deeds & Mortgages | Oct 2021 Refinance |
| Flood Zone | Zone X (minimal risk) |
| APN | 136374 |
| Primary APN | 136374 |
|---|---|
| Alternative APN |
|
| Bedrooms | 3 Beds |
|---|---|
| Full Baths | 9 Baths |
| Half Baths | 16 Half Baths |
| Total Rooms | 6 Rooms |
| Stories | 8 Stories |
| Building Area | 95,981 sqft Total Area |
| Gross Area | 101,766 sqft |
| Basement Area | 15,890 sqft |
| Unfinished Basement | 5,561 sqft |
| Year Built | Built 1982 |
|---|---|
| Effective Year Built | Effective 1982 |
| Exterior Material | Brick |
| Construction Type | Steel Frame |
| Roof Type | Flat |
| Roof Material | Other |
| Lot Area | 193,637 sqft (4.44 acres) |
| Cooling System | HVAC |
|---|---|
| Heating Fuel | Electric |
| Account Number | 136374 |
|---|---|
| Street Address | 100 5TH AVE |
| City | WALTHAM |
| State | MA |
| Zip | 02451-8703 |
| Property Category | Commercial |
| Property Type | Commercial > Office > Office Building |
| Legal Block | 6 |
| Legal Lot Number | 1 |
| Jurisdiction | WALTHAM MA |
| Township / Civil Division | WALTHAM |
| Census Block Group | 3 |
| Census Block | 3013 |
| Census Tract | 368200 |
100 5th Ave, a commercial property, is owned by a company that acquired it in December 2015.
Source: Middlesex County and Waltham City records, as of October 20, 2026
| Owner of Record | 2 Company Names on File |
|---|---|
| Mailing Address | 575 5TH AVE, NEW YORK, NY 10017-2422 |
| Owner Type | Company |
| Vesting | Company |
Owner names and exact recorded amounts are on file and can be viewed instantly on this page with a free 10-day trial.
| Deed Names | 2 Names on Deed |
|---|---|
| Last Sale | Dec 18, 2015 |
| Deed Sale | Dec 18, 2015 |
| Prior Sale | Dec 22, 2005 · Amount on File |
| Deed Document Number | 2015828 |
| Deed Book / Page | 66557 / 261 |
| Record Updated | Oct 29, 2026 |
| Document Type | Deed of Trust |
|---|---|
| Jurisdiction | WALTHAM MA |
| Property Address | 100 5TH AVE, WALTHAM, MA 02451-8703 |
| Transaction Type | Mortgage |
| Record Updated | Oct 29, 2021 |
| Name | Verified Name |
|---|
| Document Number | 78911-329 |
|---|---|
| Date | Oct 14, 2021 |
| Book Page | 78911/329 |
| Instrument | 226072 |
| Name | RBC RE CAPITAL CORP |
|---|
| Type | Stand-Alone Refinance |
|---|---|
| Amount | Amount on Record |
The 2026 property tax bill for 100 5th Ave was $697,860, up 1.6% from the year before.
Source: Middlesex County and Waltham City assessment roll, as of April 14, 2026
| Type | Name |
|---|---|
| State | Massachusetts |
| County | Middlesex County |
| Municipality | Waltham City |
| Unified School District | Waltham School District (PK - 12) |
| Year | Tax Bill | Assessed Value |
|---|---|---|
| 2026 | $697,860.00 (+1.56%) | $31,463,500 (-3.66%) Land $5,982,200 Building $25,481,300 |
| 2025 | $687,166.00 (-12.78%) | $32,660,000 (-14.15%) Land $3,718,700 Building $28,941,300 |
| 2024 | $787,897.00 (+4.1%) | $38,044,300 (+10.34%) Land $5,246,600 Building $32,797,700 |
| 2023 | $756,836.00 | $34,480,000 Land $4,769,600 Building $29,710,400 |
Assessed value is set for property tax purposes and is not a market price estimate.
FEMA maps place 100 5th Ave in Zone X, an area of minimal flood risk.
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 | 2 in force |
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 risk around 100 5th 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.
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 |
| 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.
Source: FCC Broadband Data Collection, based on 19 locations within half a mile, as of December 31, 2025
| Provider | Max Down / Up (Mbps) |
|---|---|
| Xfinity Cable | 2,000 / 2,000 |
| AT&T Fixed Wireless | 100 / 20 |
May also be available: Astound Broadband, T-Mobile, Verizon.
Search by:
By searching, you agree to: Terms • Privacy • Disclosures