Duplex Property with Detached
For Sale
$1,299,000
643 Main Street, Harwich, MA 02645
Multi-Family, Harwich, MA
Property Size2,872 SF
Lot Size1.43 Acres
Price / SF$452.30
Days on Market73
Property Features for 643 Main Street
General Information
Property type
Residential Multi Family
Property subtype
Other
Zoning description
R
Bedrooms
6
Bathrooms
3
Full bathrooms
3
Rooms
Basement, Bedroom 4, Bathroom 2, Bathroom 3, Bathroom 1, Bedroom 5, Bedroom 3, Bedroom 2, Bedroom 6, Bedroom 1
Parking
8
Parking features
Garage, Driveway, Open
Patio and Porch features
Porch, Patio
Interior features
HU Cable TV, Recessed Lighting
Exterior features
Private Yard, Garden
Fireplace
1
Basement
Full
Appliances
Water Heater, Electric Range, Dishwasher, Microwave, Refrigerator, Washer
Lot features
Cleared, Level
Elementary school district
Monomoy
Middle school district
Monomoy
High school district
Monomoy
Subdivision
Harwich
Standard status
Active
APN
HARW M:40 B: L:E4-0
Size
2,872 SF
Lot size
1.43 Acres
Taxes and HOA fees
Tax Year
2026
Tax Annual Amount
5664
Utilities
Sewer type
Septic Tank
Heating system
Oil
Cooling system
Wall Unit(s)
Water source
Public
Amenities
landscaped backyard
multiple sheds
fire pit
Building Details
Year built
1919
Floors in Building
2
Number of units
2
Flooring type
Tile, Wood, Carpet
Building materials
Shingle Siding
Roof type
Asphalt
Architectural style
Cape Cod
Listing Agency:
Keller Williams Realty
(508) 534-7200
Listed By:
Richard J Waystack · License #136018
(508) 776-0964
Added: Jul 27
Changed: Oct 6
Last Checked: Oct 7 at 12:06PM
MLS# 22605076
Copyright © 2026 Cape Cod & Islands Association of REALTORS®, Inc. All rights reserved. All information provided by the listing agent/broker is deemed reliable but is not guaranteed and should be independently verified.
Investment Insights
Based on property information with market context.
The property includes a six-bedroom main home, a separate accessory dwelling unit, and a detached mixed-use garage. The ADU has a private driveway and a history of rental use. The main residence was built in 1919 and has 2,872 square feet of property size reported. Interior features include recessed lighting, a fireplace, and carpet, tile, and wood flooring. A porch and patio supplement the outdoor areas.
Set on 1.43 acres at 643 Main Street in Harwich, the property also has a landscaped yard, garden, multiple sheds, and a fire pit. Water service is public, with septic sewer. Parking includes a driveway, open spaces, and a garage.
Set on 1.43 acres at 643 Main Street in Harwich, the property also has a landscaped yard, garden, multiple sheds, and a fire pit. Water service is public, with septic sewer. Parking includes a driveway, open spaces, and a garage.
Key Highlights
- Six‑bedroom main residence
- Separate ADU with private driveway and rental history
- Detached mixed‑use garage
Financial Insights
Estimated NOI and Cap Rate
NOI / Yr
$64,021
Cap Rate
4.93%
Suggested Prices Based on Cap Rates
Cap Rate 5%
$1,280,420
$1.3M
Cap Rate 7%
$914,586
$914.6K
Cap Rate 9%
$711,344
$711.3K
Market Conditions
NOI Build-Up for 2,872 SF
Gross rent
$94.8K $33.00/SF
− Vacancy
−$3.3K −$1.16/SF
EGI
$91.5K $31.85/SF
− OpEx
−$27.4K −$9.55/SF
NOI
$64.0K $22.29/SF
Area
Barnstable County, MA
Vacancy
3.50%
Lease Rate
$33.00 /SF/Yr
Expense Ratio
30.00%
Simulate Cap Rate and NOI
Suggested Prices Based on Cap Rates
Cap Rate 5%
$1,280,420
Cap Rate 7%
$914,586
Cap Rate 9%
$711,344
Alternative Uses
Best Use
Multifamily LT 5
$914.6K
$800.3K – $1.07M
NOI $64,021 @ 7.0% cap · market cap 4.93%
Second Best
Apartment 5plus
$822.1K
$719.4K – $959.2K
NOI $57,550 @ 7.0% cap · market cap 4.43%
Theoretical Best
Office A
$1.17M
$1.02M – $1.37M
NOI $81,925 @ 7.0% cap · market cap 6.31%
Zoning and permitted uses should be independently verified with authorities.
Property Analytics
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Current Use
Lease Details
2
Residential units
Location Intelligence
Trade Area within ½ mile
166
Businesses Nearby
Explore this area
Business Placement
Demographics for 02645, MA
10,436
Population
6,745
Households
1.5
Avg Household Size
55
Median Age
43%
College-Educated
99%
High-School Grad
16.9 sq mi
ZIP Area
618
Density / Sq Mi
$89,898
Median Household Income
$56,692
Median Earnings
$1,809
Median Rent
$581,200
Median Home Value
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Cap Rate, Value Estimation, Potential NOI and more
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Market
Vacancy Rate% for Multifamily in Northeast region
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Frequently Asked Questions
What type of property is this?
Duplex - A six-bedroom main residence is accompanied by a separate accessory dwelling unit with its own driveway.
Where is this duplex located?
The property is located at 643 Main Street Harwich, MA.
What is the asking price?
The asking price for this property is $1,299,000.
What are key features of this property?
This property features: Six‑bedroom main residence; Separate ADU with private driveway and rental history; Detached mixed‑use garage
