Updated: May 23, 2026
Location and Projects
Address
3555 TRIESTE DR, Carlsbad, CA, 92010
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Ko Plumbing
Ko Plumbing, 3555 Trieste Dr, Carlsbad, CA (Employees: Alfred Ortega Rojas Jr, Gina Florence Osborn, and Koichi Kusano) holds a Plumbing license and 3 other licenses according to the California license board.
Their BuildZoom score of 101 ranks in the top 12% of 336,931 California licensed contractors.
Their license was verified as active when we last checked. If you are thinking of hiring Ko Plumbing, we recommend double-checking their license status with the license board and using our project planner to get competitive quotes.
Ko Plumbing Services
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Ko Plumbing Contact Information
Phone Number: (619) 994-3562
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Address: 3555 TRIESTE DR, Carlsbad, CA 92010
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This is a sample of this contractor's permits. Click here to access their complete permit history.
Wmsr-03: plumbing repipe | additional details: repipe with pex pipe overhead to serve 1 bathroom to include tub/shower lavatory and toilet. new tub/shower valve
Valuation:
N/A
Permit #:
00883578-WMSR
Status:
issued
Fee:
$88
Permit Type:
N/A
Building Type:
N/A
Repipe of water supply system
Valuation:
N/A
Permit #:
00837084-WMSR
Status:
final
Fee:
N/A
Permit Type:
N/A
Building Type:
N/A
Re-pipe replace service line and change out water heater (40gal)
Valuation:
N/A
Permit #:
18-3119
Status:
expired
Fee:
$249
Permit Type:
N/A
Building Type:
N/A
Relocate tankless water heater entered by: daleyj
Valuation:
N/A
Permit #:
P2020-006000
Status:
final
Fee:
N/A
Permit Type:
N/A
Building Type:
N/A
Water repipe and water softner pex repipe with uponor to 15 fixtures and 4 hose bibs
Valuation:
$0
Permit #:
PB152153
Status:
Issued
Fee:
$362
Permit Type:
N/A
Building Type:
N/A
R3 u1 1st floor remodel kit create lndry room demolish f p in liv room addition coat clst addition wndw entry c o 3 wndws in liv room din room 2nd floor rmdl decrease size of bathroom replace sliding glass door create study rmv replace closet in mstr bedroom
Valuation:
N/A
Permit #:
PLM02-01344
Status:
final
Fee:
$89
Permit Type:
N/A
Building Type:
N/A
For sf/add alter (replacing part of water service in front of home replacement of gas line and replacement of partial sewer line)
Valuation:
N/A
Permit #:
B00-027-627
Status:
final
Fee:
$134
Permit Type:
N/A
Building Type:
N/A
Kitchen remodel. replace/install kitchen sink garbage disposal and dishwasher. to include relocation of gas stove
Valuation:
N/A
Permit #:
06042-10000-01347
Status:
final
Fee:
N/A
Permit Type:
Commercial
Building Type:
N/A
Supplemental to permit # 07042-10000-06357 to replace water service from meter to house. pipe size is 1 1/2
Valuation:
$0
Permit #:
07042-10001-06357
Status:
Permit Finaled
Fee:
N/A
Permit Type:
1 or 2 family dwe...
Building Type:
N/a
Supplemental to permit #10044-10000-02023 for (2) wall heater vents & (8) system component (inlet/outlets)
Valuation:
N/A
Permit #:
10044-10001-02023
Status:
final
Fee:
N/A
Permit Type:
Commercial
Building Type:
N/A
Replace one existing wall heater with new 25, 000 btu wall heater. for unit #c. permit approved by eng. brm
Valuation:
N/A
Permit #:
97044-10000-08711
Status:
final
Fee:
N/A
Permit Type:
Commercial
Building Type:
N/A
Replace water main from water meter to house. install water pressure regulator and hose bibb
Valuation:
N/A
Permit #:
PLM2006-01429
Status:
final
Fee:
N/A
Permit Type:
plumbing permit
Building Type:
N/A
Install gas outlets for fixtures. to include (1) 1/2 water line for make-up air units on roof
Valuation:
N/A
Permit #:
06042-10000-21871
Status:
final
Fee:
N/A
Permit Type:
Commercial
Building Type:
N/A
Water service from meter to houses (2006/2008) - replace piping to fixtures inside house
Valuation:
N/A
Permit #:
PLM2009-00368
Status:
final
Fee:
N/A
Permit Type:
plumbing permit
Building Type:
N/A
Install new fixtures for 2nd floor bathroom addition 1 bar sink and 2 gas outlets
Valuation:
N/A
Permit #:
07042-20000-22401
Status:
final
Fee:
N/A
Permit Type:
1 or 2 family dwe...
Building Type:
N/A
Office use for plumbing services (no employees) ** is now a cslb 964288, needs bac also
Valuation:
$0
Permit #:
BUS2009-02717
Status:
Finaled
Fee:
N/A
Permit Type:
N/A
Building Type:
N/A
Remodel existing kitchen laundry and bathroom. new bathroom addition above garage
Valuation:
$0
Permit #:
07042-10000-06357
Status:
Permit Finaled
Fee:
N/A
Permit Type:
1 or 2 family dwe...
Building Type:
N/a
Supplemental to permit# 06042-10000-28824 to addition on (2) more gas outlets
Valuation:
N/A
Permit #:
06042-10001-28824
Status:
final
Fee:
N/A
Permit Type:
Commercial
Building Type:
N/A
Repire hot and cold water to 7 fixtures and install a new garbage disp osal
Valuation:
N/A
Permit #:
96042-10000-00817
Status:
final
Fee:
N/A
Permit Type:
1 or 2 family dwe...
Building Type:
N/A
Replace section of gas pipe under slab (concrete floor - 4 branch line
Valuation:
$0
Permit #:
PLM2002-01144
Status:
Final
Fee:
N/A
Permit Type:
Gas
Building Type:
N/A
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Verified License
BuildZoom confirmed this contractor's license
Ko Plumbing License info
Verified License
| License # | 1145043 |
| Status | Active |
| State | California |
| Type | Plumbing |
| Date Issued | 10-14-2025 |
| Business Type | Sole Ownership |
- BuildZoom verified this license was active as of April 2026.
Verify this license's status for Ko Plumbing at the California Contractors State License Board.
This is a sample of licensing data; click here to access a complete history.
Verified License
| License # | 964288 |
| Status | Active |
| State | California |
| Type | Plumbing |
| Business Type | Sole Ownership |
- BuildZoom verified this license was active as of April 2026.
Verify this license's status for Ko Plumbing at the California Contractors State License Board.
This is a sample of licensing data; click here to access a complete history.
Inactive License
| License # | 493048 |
| Status | Inactive |
| State | California |
| Type | Plumbing, Warm Air Heating, Ventilating And Air Conditioning |
| 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 Ko Plumbing at the California Contractors State License Board.
This is a sample of licensing data; click here to access a complete history.
Inactive License
| License # | 380003 |
| Status | Inactive |
| State | California |
| Type | Warm Air Heating, Ventilating And Air Conditioning, Plumbing |
| 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 Ko Plumbing at the California Contractors State License Board.
This is a sample of licensing data; click here to access a complete history.
101
BuildZoom Score
Bonded
| Bonded Agent | Hudson Insurance Company |
| Bond Value | $15,000 |
Insured
| Workers Comp Provider | Southern Insurance Company |
116
Permits
- Building permit records show that Ko Plumbing has worked on 116 permitted projects.
Ko Plumbing Employees
AJ
Alfred Ortega Rojas Jr
Sole Owner
GO
Gina Florence Osborn
Officer
KK
Koichi Kusano
Rmo / Ceo / Pres
KO
Kyle Nathan Osborn
Rmo / Ceo / Pres
LK
Lillian Asako Kusano
Officer
MO
Mitsumasa Omori
Officer
TM
Tom Murakami
Rme
TM
Tom Murakami
Rme