Updated: Jul 15, 2026
Location and Projects
Headquarters Address
21013 HWY 140 EAST, Dairy, OR, 97625
Local address
2027 WILLOW WAY, San Bruno, CA, 94066
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Thomas I Mahon Construction
Thomas I Mahon, 2027 Willow Way, San Bruno, CA (Employees: Isidore Joseph Mahon and Thomas Isidore Mahon) holds a General Building license and 1 other license according to the California license board.
Their BuildZoom score of 93 ranks in the top 27% of 336,931 California licensed contractors.
Their license was verified as active when we last checked. If you are thinking of hiring Thomas I Mahon, we recommend double-checking their license status with the license board and using our bidding system to get competitive quotes.
Thomas I Mahon Services
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Thomas I Mahon Contact Information
Phone Number: (415) 902-8199
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Headquarters Address: 21013 HWY 140 EAST, Dairy, OR, 97625
Local Address: 2027 WILLOW WAY, San Bruno, CA 94066
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This is a sample of this contractor's permits. Click here to access their complete permit history.
Kitchen remodel. new hood jack. move sink to window. move stove and replace. addition led 4 ceiling lights and addition water for ice maker. new cabinets and counter tops and floor tile. new garden window also addition new gfci outlets for ktichen counter and ground fault breaker for other outlets will addition new electrical sub panel in wall under kitchen on first floor
Valuation:
N/A
Permit #:
BLD2018-00208
Status:
final
Fee:
$2,392
Permit Type:
N/A
Building Type:
N/A
Change of use from retail to medical service (chiropractor office) install new partitions and doors in existing g/f tenant space. no mechanical or plumbing work existing flooring ceiling and lighting to remain
Valuation:
$40,000
Permit #:
201512074323
Status:
complete
Fee:
N/A
Permit Type:
N/A
Building Type:
10 - office
Install chair lift for barrier removal for wheel chair access to mezzanine level addition blocking cut opening through guard wall on mezzanine. n/a ordinance #155-13
Valuation:
$48,000
Permit #:
201408133694
Status:
complete
Fee:
N/A
Permit Type:
N/A
Building Type:
10 - office
New 2 story single family residence with decks and detached 2 car garage. resubmittal # 1 - 09/27/94 - jpb - change garage from detached to underneath house window changes revised elevations increase deck. building new retaining wall in rear of property. resubmittal #2 06-09-05 slg - archietctural structural plumbing comments per winfreds letter dated 03-24-1995. revision # 1 - jpb - ... see more
Valuation:
$16,530
Permit #:
BLD94-0545
Status:
Finaled
Fee:
$10,193
Permit Type:
N/A
Building Type:
N/A
New 3 story single family residence with attached garage and 2 decks. resubmittal - jpb - 09/09/92 - new driveway profile. resubmittal 11-10-92 slg - relocate furnace water heater washer/dryer to another area relocate bathroom from entry hall. new title 24. revision 09-13-93 slg - added 2 retaining walls side of garage and adjacent to driveway. 34 maximum height
Valuation:
$11,312
Permit #:
BLD92-0842
Status:
final
Fee:
$6,499
Permit Type:
N/A
Building Type:
N/A
New 2 story single family dwelling with attached garage and decks. resubmittal # 1 - jpb - 12/11/95 - as requested by winfred in his letter dated 12/06/95. revision #1 02-07-97 slg - topo submitted to resolve violation. resubmittal # 1 - jpb - 02/14/97 - additional site information
Valuation:
$9,681
Permit #:
BLD95-0210
Status:
final
Fee:
$7,748
Permit Type:
N/A
Building Type:
N/A
Two story single family dwelling with attached garage. resubmittal # 1 - jpb - 10/02/98 - minor change to garage door size and delete 2nd floor cantilever resubmittal #2 - 04/20/99 eta - submitting soils report resubmittal #3 5/26/99 mjp - topograpic survey and corrections per winfreds letter
Valuation:
$5,498
Permit #:
BLD98-1062
Status:
final
Fee:
$8,345
Permit Type:
N/A
Building Type:
N/A
New 2-story single family dwelling with attached garage & decks resubmittal # 1 - jpb - 07/07/98 delete lower level kitchen & addition wet bar resubmittal # 2 - change in driveway resubmittal # 3 - mjp - 06/08/99 topo map structural calcs - corrections per winfred sewer correction resubmittal # 4 - jpb 06/18/99 as requested by winfred in his letter dated 06/11/99 revision - 1 jpb 11/0... see more
Valuation:
$12,384
Permit #:
BLD98-0785
Status:
final
Fee:
$10,222
Permit Type:
N/A
Building Type:
N/A
New single family residence with attached 2 car garage resubmittal #1 - 04/20/99 eta - submitting soils report resubmittal #2 5/26/99 mjp - topographical survey and corrections per winfreds letter resubmittal #3 mjp 6/8/99 - raise in elevation per sewer revision #1 mjp 10/4/00 - drainage plan revision #2 tn 10/06/00 - drainage plan
Valuation:
$3,976
Permit #:
BLD98-1094
Status:
final
Fee:
$5,878
Permit Type:
N/A
Building Type:
N/A
Single story single family dwelling with attached garage. resubmittal #1 - 04/20/99 eta - submitting soils report resubmittal #2 5/26/99 mjp - topographic survery & correction per winfreds letter resubmittal #3 6/8/99 mjp - submitting of plans necessary to raise elevation per sewer department revision #1 mjp 10/4/00 - drainage plan
Valuation:
N/A
Permit #:
BLD98-1095
Status:
final
Fee:
$4,662
Permit Type:
N/A
Building Type:
N/A
Single story single family residence with attached garage resubmittal #1 - 04/20/99 eta - submitting soils report resubmittal #2 5/26/99 mjp - topographical survey and correction per winfreds ltr resubmittal #3 6/8/99 mjp - resubmittal of entire plans design has had to be reversed due to a pole located in the middle project resubmittal # 4 - jpb - 11/08/99 - 2 copies of topo survey an... see more
Valuation:
$3,912
Permit #:
BLD98-1096
Status:
final
Fee:
$5,034
Permit Type:
N/A
Building Type:
N/A
New 3 story single family residence with attached 2 car garage and 2 decks. resubmittal 04-28-94 slg - revise building height on elevation. resubmittal - jpb - 12/01/94 - as requested mr cameron in his letter dated 11/14/94
Valuation:
$11,220
Permit #:
BLD94-0387
Status:
Finaled
Fee:
$7,792
Permit Type:
N/A
Building Type:
N/A
New 2 story single family residence with decks and detached 2 car garage. resubmittal # 1 - 09/27/94 - jpb - change garage from detached to underneath house window changes revised elevations increase deck. building new retaining wall in rear of property. resubmittal #2 06-09-05 slg - archietctural structural plumbing comments per winfreds letter dated 03-24-1995. revision # 1 - jpb - ... see more
Valuation:
$16,530
Permit #:
BLD94-0545
Status:
final
Fee:
$10,193
Permit Type:
N/A
Building Type:
N/A
Remodel kitchen and rewire for outlet. install new light fixture for living room. 100 amp feeder 9 circuits 40 lights 8 switches 16 receptacles 1 fan 1 dishwasher and 1 microwave
Valuation:
$0
Permit #:
E201106215746
Status:
ISSUED
Fee:
N/A
Permit Type:
N/A
Building Type:
N/A
New 3 story single family residence with attached 2 car garage and 2 decks. resubmittal 04-28-94 slg - revise building height on elevation. resubmittal - jpb - 12/01/94 - as requested mr cameron in his letter dated 11/14/94
Valuation:
$11,220
Permit #:
BLD94-0387
Status:
final
Fee:
$7,792
Permit Type:
N/A
Building Type:
N/A
Building new two story residence with attached garage and decks. resubmittal 01-06-94 slg - architectural structural plumbing comments per winfreds comment letter dated 12-27-93
Valuation:
$9,630
Permit #:
BLD93-1269
Status:
final
Fee:
$7,235
Permit Type:
N/A
Building Type:
N/A
Sfd/response to inquiry sfd/response to inquiry inquiry from neighbor tom dunkelman (apn: 037-181-040 460 cypress) regarding project's particulars including grading operations
Valuation:
$0
Permit #:
MNA1999-00013
Status:
Closed
Fee:
N/A
Permit Type:
N/A
Building Type:
N/A
Converted: tenant improvement. - addition of 360 sq. ft separate permits r
Valuation:
$157,000
Permit #:
B-TI2003-32
Status:
final
Fee:
$4,935
Permit Type:
Commercial
Building Type:
N/A
Install fire sprinklers to single family dwelling with attached garage 05/11/99 eta - cancelling this permit as there is an existing permit plumbing 1999-00101
Valuation:
$3,000
Permit #:
PLM1999-00121
Status:
canceled
Fee:
$119
Permit Type:
N/A
Building Type:
N/A
Replace kitchen cabinets top & flooring new led ceiling lights insulate ceiling replace back and light well windows 9 total
Valuation:
$12,000
Permit #:
201106218603
Status:
complete
Fee:
N/A
Permit Type:
N/A
Building Type:
28 - 2 family dwe...
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Thomas I Mahon License info
Verified License
| License # | 699054 |
| Status | Active |
| State | California |
| Type | General Building |
| Business Type | Sole Ownership |
- BuildZoom verified this license was active as of July 2026.
Verify this license's status for Thomas I Mahon at the California Contractors State License Board.
This is a sample of licensing data; click here to access a complete history.
Inactive License
| License # | 359670 |
| Status | Inactive |
| State | California |
| Type | General Building |
| Business Type | Sole Ownership |
- According to the California Contractors State License Board, the status of this license was at one point cancelled. However, this information may have changed. If this is your business, please update your license status.
Check this license's status for Thomas I Mahon at the California Contractors State License Board.
This is a sample of licensing data; click here to access a complete history.
93
BuildZoom Score
Bonded
| Bonded Agent | Hudson Insurance Company |
| Bond Value | $15,000 |
Insured
| Workers Comp Provider | State Compensation Insurance Fund |
39
Permits
- Building permit records show that Thomas I Mahon has worked on 39 permitted projects.
Thomas I Mahon Employees
IM
Isidore Joseph Mahon
Sole Owner
TM
Thomas Isidore Mahon
Sole Owner