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California / Walnut Creek / ADU builders

ADU builders in Walnut Creek, California

The short answer

34 licensed contractors building accessory dwelling units in Walnut Creek. Every licence below was checked against the California state register. Walnut Creek does not publish contractor names on building permits, so this list ranks on licence standing and pre-approved plans.

California Contractors State License Board, checked 2026-08-15
How to read this. Licence details come from the California Contractors State License Board and are dated on each profile. Permit counts reflect only those cities that publish the contractor's name on a building permit, so a builder with none listed may simply have worked where nothing is published. A city that pre-approves a plan has vetted the plan, not the builder, and does not endorse it. ADU Standards takes no payment for placement. Confirm any licence at cslb.ca.gov before you sign.

Ordered by what the records confirm

The list
2

H D R Remodeling Inc

Licensed Licence clear 30 years licensed Workers’ comp on file

CSLB #720621 · EMERYVILLE

7

Inspired Builders Inc

Nearby permits Licence clear 4 years licensed Workers’ comp on file

CSLB #1088894 · SUNNYVALE

8

Imkat Construction Corp

Nearby permits Licence clear 4 years licensed Workers’ comp on file

CSLB #1094866 · SACRAMENTO

9

Fusionfit

Licensed Licence clear 9 years licensed Workers’ comp on file

CSLB #1020923 · WALNUT CREEK

10

Green Group Roofing

Licensed Licence clear 7 years licensed Workers’ comp on file

CSLB #1051717 · CONCORD

12

Mana Construction Inc

Licensed Licence clear 7 years licensed Workers’ comp on file

CSLB #1043320 · VALLEJO

14

Tgi Builders CA Inc

Licensed Licence clear 5 years licensed No workers’ comp on file

CSLB #1079673 · SAN JOSE

15

Home By Tom Inc

Licensed Licence clear 5 years licensed Workers’ comp on file

CSLB #1079020 · MORAGA

16

Edri Construction Inc

Licensed Licence clear 5 years licensed Workers’ comp on file

CSLB #1070193 · SAN FRANCISCO

19

Type Five Inc

Licensed Licence clear 4 years licensed Workers’ comp on file

CSLB #1086540 · BERKELEY

22

We Do Construction Inc

Licensed Licence clear 3 years licensed Workers’ comp on file

CSLB #1096552 · SAN FRANCISCO

23

Adapt Dwellings Inc

Licensed Licence clear 3 years licensed No workers’ comp on file

CSLB #1098831 · OAKLAND

24

Nest Builders

Licensed Licence clear 2 years licensed No workers’ comp on file

CSLB #1117837 · MILL VALLEY

27

ADU Crew Llc

Licensed Licence clear 1 years licensed Workers’ comp on file

CSLB #1139240 · CLAYTON

28

Optivest Build Inc

Licensed Licence clear 0 years licensed Workers’ comp on file

CSLB #1144711 · WALNUT CREEK

29

American Builders

Licensed Licence clear 13 years licensed Workers’ comp on file

CSLB #979992 · PACIFICA

31

Green Bay Remodeling Inc

Licensed Licence clear 12 years licensed Workers’ comp on file

CSLB #993580 · WALNUT CREEK

32

Hbc Construction

Licensed Licence clear 27 years licensed No workers’ comp on file

CSLB #762903 · FREMONT

34

Royalty Builders Inc

Licensed Licence clear 7 years licensed No workers’ comp on file

CSLB #1048623 · WOODLAND HILLS

What Walnut Creek charges

The city’s published schedule

Walnut Creek does not publish a fee schedule specific to accessory dwelling units. What follows is from its general schedule (FY2026 and FY2027), so expect to confirm the figures with the permit counter. These are city fees only. They do not include what a builder charges to design and build the unit.

Plan check
basis percentage of building permit fee
detail Building Plan Review Fee shall be 100 percent of the Building Permit Fee. Electrical plan review 25% of the sum of the building, electrical, plumbing and mechanical permit fees; plumbing plan review 25%; mechanical plan review 25%. Green Building Code Plan Review Fee applies for CALGreen. Expedited Plan Review Fee, at applicant's option: surcharge equal to 50% of the normal plan review fees to provide plan review within one half of the published turnaround schedule. All valuation-table-based permits include up to two rounds of plan review and one final back check; additional corrections are billed hourly.
hourly note Standard plan check fees are calculated based on the ICC construction cost table as modified by the City.
as of FY2026 and FY2027 adopted
Building permit
basis valuation-based table (identical FY2026 and FY2027 rates)
detail $2,000 to $25,000: $80.01 for the first $2,000 plus $16.19 for each additional $1,000 or fraction thereof. $25,000 to $50,000: $452.38 for the first $25,000 plus $11.75 per additional $1,000. $50,000 to $100,000: $746.13 for the first $50,000 plus $8.26 per additional $1,000. $100,000 to $500,000: $1,159.13 for the first $100,000 plus $6.67 per additional $1,000. $500,000 to $1,000,000: $3,827.13 for the first $500,000 plus $5.40 per additional $1,000. $1,000,000 and up: $6,527.13 for the first $1,000,000 plus $3.81 per additional $1,000.
consolidated mep For new residential dwellings and private garages, the building permit also serves as the electrical, plumbing and mechanical permit; the building permit fee is increased by 55 percent. For additions and alterations to existing residential dwellings: electrical inspection 20% of building permit fee, plumbing inspection 18%, mechanical inspection 17%.
technology fee 1.25% of the combined total of permit fees and plan review fees.
as of FY2026 and FY2027 adopted
School district fees
rate Not published by the City.
verbatim School fees are based on the valuation of the project. Contact your applicable school district to confirm what fees may apply.
note The City's characterization of school fees as valuation-based does not match Educ. Code sec. 17620, under which Level 1 school facilities fees are assessed per square foot of assessable space, not on valuation. Districts serving Walnut Creek set and collect their own rates.
Utility connections
verbatim Contact water, sanitary, and any other utility districts to see if any connection fees will be required for your project.
water East Bay MUD, not a City fee.
sewer Central Contra Costa Sanitary District, not a City fee.
source ADU page, 'How to Apply' step 2
Impact fees
categories published Development impact fees listed by category with no rates on the fees page: Parkland dedications (required for all net new residential development), Inclusionary housing, Commercial linkage, Parking in-lieu, Public art, Traffic impact (required for all net new residential units), Tree mitigation, Drainage, CA Department of Fish & Game.
adu handbook mention The ADU Handbook lists 'Development impact fees' as a line item in its cost checklist but states no rate and no ADU exemption.
city statement on adus No statement about the sec. 66311.5 under-750 exemption appears on the ADU page, in the ADU Handbook, in the Building Permit Submittal Requirements: ADUs and JADUs, or in the Master Fee Schedule.

Walnut Creek’s published schedule does not mention the exemption for ADUs under 750 square feet. California Government Code section 66311.5(c)(1) bars a local agency from imposing impact fees on an accessory dwelling unit of less than 750 square feet. If you are quoted impact fees on a unit that size, ask the city which section authorises them.

Walnut Creek fee scheduleFee schedule PDF

Common questions

How is this list ordered?

By what can be confirmed in public records: the number of accessory dwelling unit permits each contractor has on file in Walnut Creek, whether Walnut Creek has pre-approved their plans, and their licence standing with the California Contractors State License Board. No builder pays for position and none can request removal.

Are these builders licensed?

Every company listed has been matched to an active California contractor licence and its standing is shown on the card. California law requires a contractor to display its licence number in all advertising, and we check the number shown against the state register before publishing anything a company says about itself.

Why do some show no permit history?

Most California cities do not publish the contractor's name on a building permit. Where a city does not publish it, we cannot confirm completed work, so the card says the licence is verified and nothing more. Ask a builder directly for recent addresses and permit numbers you can look up.

What does it mean that Walnut Creek pre-approved a builder's plans?

Under Government Code section 65852.27 every California city must accept ADU plans for pre-approval and publish the resulting list. A pre-approved plan has cleared plan check in advance, which shortens permitting. It is an approval of the plan, not an endorsement of the company that drew it.

Companies we looked at and left out

Also considered

These came up when looking for ADU builders in Walnut Creek but did not meet the bar for the list above, usually because they do not advertise a California licence number, do not name Walnut Creek as an area they serve, or do not present accessory dwelling units as a service they offer. They are shown so the list above can be checked rather than taken on trust.

Four checks worth ten minutes.

Before you sign
  1. Look the licence up yourself at cslb.ca.gov. It takes under a minute and shows the current status, any suspensions, and the bond.
  2. Ask who carries workers’ compensation for the crew and for every subcontractor. A licensee with no employees may lawfully be exempt, but if someone is hurt on your property you can end up treated as the employer.
  3. Ask for two recent permit numbers in any city, then look them up. A builder who has done the work can produce them immediately.
  4. Get the price in writing against a drawing set. A published starting price is for a base model and rarely includes site work, utilities, or Walnut Creek fees.