Updated: May 02, 2026
Location and Projects
Address
113 W SANTA FE AVE, Fullerton, CA, 92832
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Custom Adu Builder Construction
Serving homeowners across Fullerton and surrounding communities, Custom Adu Builder specializes in the design and construction of accessory dwelling units (ADUs). Active for three years, the company focuses on maximizing residential property value and utility through the addition of custom-built ADUs tailored to each client’s needs. Project experience includes detached ADU structures, garage conversions, and internal ADU remodels that integrate seamlessly with existing homes. Custom Adu Builder guides clients from initial planning and permit acquisition through all phases of construction, ensuring projects meet local regulations and space requirements. The team’s work frequently involves optimizing layouts for limited lot sizes and incorporating modern features such as energy-efficient windows and flexible living areas. The company primarily serves residential property owners looking to create additional living space or rental opportunities.
Custom Adu Builder Services
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Custom Adu Builder Contact Information
Phone Number: (714) 488-3160
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Address: 113 W SANTA FE AVE, Fullerton, CA 92832
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Custom Adu Builder Fullerton
Quality
104
91st percentile
Pro tip:
We generally recommend hiring a contractor with a score higher than 95.
Custom Adu Builder has a BuildZoom score of 104, which places them above 91% of 336,931 contractors in California.
Activity
|
7 projects
|
2025 |
|
5 projects
|
2024 |
|
2 projects
|
2023 |
Our building permit records indicate that Custom Adu Builder has worked on at least
14.0 projects over the past 3 years.
This is an overview of this contractor's activity. Click here to access our complete licensing and building permit database.
This is an overview of this contractor's activity. Click here to access our complete licensing and building permit database.
Experience
|
6 projects
|
New Constructions |
Analyzing permits over the last 4 years shows that Custom Adu Builder mostly works on
new construction
projects.
Pricing
|
3 projects
|
< $5k |
|
6 projects
|
$50k-$100k |
|
4 projects
|
$100k-$250k |
The typical size of their permits is approximately $77,587. This graph shows the distribution of these job values.
Pro tip:
For more details about their pricing, check out their recent activity to see how much they have charged for different types of work.
This is a sample of this contractor's permits. Click here to access their complete permit history.
Revised scope of work: building (n) 839.69 sqft 2-story (2) bedroom (2) bathroom adu; electrical service to be separated via (n) overhead service wire for 225 amp main; (e) single family residence panel to in same location; water to be connected from (e) service line; gas to be connected from (e) utility; (n) sewer to be connected to (e) 4 lateral of single family residence downline; ... see more
Valuation:
N/A
Permit #:
MIS-2025-0190
Status:
issued
Fee:
$290
Permit Type:
N/A
Building Type:
N/A
Convert (e) 363 sqft detached 2-car garage into (n) 840 sqft 2-story (2) bedrooms (2) bathrooms detached adu with 12 sq ft covered porch 1st floor - 486 sq ft 2nd floor - 354 sq ft includes all related mechanical electrical and plumbing as per approved plans
Valuation:
$190,000
Permit #:
COMR-2024-0347
Status:
issued
Fee:
$4,496
Permit Type:
N/A
Building Type:
N/A
Construct (n) 499 sq ft (1) bedroom (1) bathroom attached adu includes plumbing electrical and mechanical this parcel lies within a liquefaction zone as per approved plans
Valuation:
$82,000
Permit #:
COMR-2024-0166
Status:
issued
Fee:
$2,554
Permit Type:
N/A
Building Type:
N/A
Detached garage with an addition to be convered into a 2 story adu per ca govt. code 65852.2(e)(1)(b) and applicable part 2 of lamc 12.22 a.33 (c)-(d) (g)
Valuation:
$200,000
Permit #:
24014-30000-01144
Status:
final
Fee:
N/A
Permit Type:
1 or 2 family dwe...
Building Type:
N/A
Residential supplemental fees - construct (n) 499 sq ft detached (1) bedroom (1) bathroom adu sanitation fee 499 sq ft x $1.659 = $827.84
Valuation:
N/A
Permit #:
MIS-2025-0089
Status:
complete
Fee:
$828
Permit Type:
N/A
Building Type:
N/A
(e plan) detached adu (primary: 8 e trenton unit 1 adu: 8 e trenton unit 2) (under 750sf)
Valuation:
$66,877
Permit #:
00952991-RBPR
Status:
issued
Fee:
$1,613
Permit Type:
N/A
Building Type:
N/A
Residential supplemental fees - convert (e) 363 sqft detached 2-car garage to create (n) 840 sqft 2-story detached (2) bedrooms (2) bathrooms adu with 12 sqft covered porch sanitation fee 477 sqft x $1.485 = $708.35
Valuation:
N/A
Permit #:
MIS-2024-0441
Status:
complete
Fee:
$708
Permit Type:
N/A
Building Type:
N/A
New attached adu to rear of detached garage; 588sf; (1) bedroom closet bathroom laundry room living room kitchen and dining area w/m/e/p's.(adu 23- 24)
Valuation:
$135,000
Permit #:
B-23-779
Status:
issued
Fee:
$2,003
Permit Type:
N/A
Building Type:
N/A
Detached garage converted to adu 413 sf 1 bed 1 bathroom new tankless water h e a t e r s u b p a n e l mini-split e/m/p (adu- 23-49)
Valuation:
$65,000
Permit #:
B-23-1550
Status:
issued
Fee:
$1,327
Permit Type:
N/A
Building Type:
N/A
1 bedroom 1 bathroom adu
Valuation:
$100,000
Permit #:
COMR-2025-0455
Status:
filed
Fee:
N/A
Permit Type:
N/A
Building Type:
N/A
New 499 sf adu construction above existing garage 1 bed 1 bathroom and stairs
Valuation:
$140,000
Permit #:
B-24-395
Status:
issued
Fee:
$2,644
Permit Type:
N/A
Building Type:
N/A
Detached garage converted to adu 4 4 7 s f 1 o n e 1 b a t h new tankless mini- split sub-panel; e/m/p
Valuation:
$65,000
Permit #:
B-23-1549
Status:
issued
Fee:
$1,327
Permit Type:
N/A
Building Type:
N/A
Supplemental to 24014-30000-01144 to provide details for new foundation due to field conditions for the south and east walls
Valuation:
$2,500
Permit #:
24014-30002-01144
Status:
final
Fee:
N/A
Permit Type:
1 or 2 family dwe...
Building Type:
N/A
458 sf adu garage conversion 1 bed 1 bathroom as per approved plans
Valuation:
$90,000
Permit #:
10283740
Status:
filed
Fee:
$271
Permit Type:
V-b
Building Type:
N/A
(eplan) residential addition
Valuation:
$73,173
Permit #:
00918862-RBPR
Status:
final
Fee:
$1,020
Permit Type:
N/A
Building Type:
N/A
Electric panel
Valuation:
N/A
Permit #:
BLD-2023-01560
Status:
issued
Fee:
$225
Permit Type:
N/A
Building Type:
N/A
Relocation of electrical panel and water heater and mini split condenser per sce during inspection. permit number comr -2025- 0111
Valuation:
$0
Permit #:
MIS-2025-0906
Status:
filed
Fee:
$300
Permit Type:
N/A
Building Type:
N/A
Residential supplemental fees - construct 1 860 sqft (2) (n) (3) bedrooms (2) bathroom detached adu stacked ref: comr-2025-0334 sanitation fee 930 sqft x $1.695 = $1 576.35 [adu a] 930 sqft x $1.695 = $1 576.35 [adu b]
Valuation:
$0
Permit #:
MIS-2025-0901
Status:
complete
Fee:
$3,153
Permit Type:
N/A
Building Type:
N/A
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Custom Adu Builder Reviews
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Verified License
BuildZoom confirmed this contractor's license
Custom Adu Builder License info
Verified License
| License # | 1101360 |
| Status | Active |
| State | California |
| Type | General Building |
| Business Type | Sole Ownership |
- BuildZoom verified this license was active as of May 2026.
Verify this license's status for Custom Adu Builder at the California Contractors State License Board.
This is a sample of licensing data; click here to access a complete history.
104
BuildZoom Score
Bonded
| Bonded Agent | This License Filed A Contractor's Bond With |
| Bond Value | $25,000 |
Insured
| Workers Comp Provider | State Compensation Insurance Fund |
14
Permits
- Building permit records show that Custom Adu Builder has worked on 14 permitted projects.
Custom Adu Builder Employees
DR
Dennis Ray Robinson
Sole Owner