The Complete Guide to
Building an ADU in Concord, CA

Everything Concord homeowners need to plan, permit, and profit from an ADU — including current 2026 zoning rules, real construction costs, neighborhood ROI data, and verified local lenders.

Calculate Your ADU's ROI ↓ Check Concord's ADU Rules ↓

Created by Build With A Plan · Drawings from $997 (more below)

Quick Answers About Concord, CA ADUs

ADUs Allowed
Up to 1,200 sq ft
20 ft max height
🏠
Owner Occupancy
Not required
CA state law applies
📊
Average Build Cost
$450/sqft
verified 2026
💰
Avg Rental Income
$1,840/mo
1BR ADU · verified data
Modern detached ADU in a California backyard — completed project in Concord
Completed Project · Concord
Interior of a permitted ADU studio unit — open-plan living and kitchen
Build With A Plan · Permit-Ready Drawings from $997

Market Context

Concord has a median home value of $680,000. Adding an ADU typically increases that by 25% — approximately $170,000 in added equity. A 1-bedroom ADU in Concord rents for approximately $1,840/month in the Contra Costa County rental market , yielding a 4.1% cap rate on the investment. Occupancy averages 96% in this market.

Top Concord neighborhoods for ADU investment include Cowell Terrace, Shadelands, Vista Diablo/Wilshire Estates, The Highlands, Crawford Village. Large single-family lots and proximity to Concord BART make it ideal for detached ADUs. Large lots and predominantly single-family zoning with higher incomes support ADU projects.

Permit Process

Permit applications are reviewed by the Community Development Department , with a plan check timeline of approximately 8 weeks. Permit fees in Concord range from $3,500 to $12,000 depending on project scope. Design review: Yes - for non-exempt ADUs (citywide) via Concord's Design & Site Review process

Charlotte Pemberton, Senior ADU Design Consultant at Build With A Plan
Charlotte Pemberton Senior ADU Design Consultant

11 years in California residential permitting and ADU documentation. This guide was researched and verified against Concord's building department records and current 2026 California ADU law.

Is My Concord, CA Property Eligible for an ADU?

Concord homeowners benefit from California's state ADU law — one of the most permissive frameworks in the country since 2020. Here's what applies to your property before you start designing.

Single-Family Home

Permitted on single-family lots in Concord under California state law. No owner-occupancy requirement in Concord — you can rent both units as investment properties. Ministerial permit approval — no neighbor input or discretionary design review.

Multi-Family Property

Up to 2 detached ADUs plus JADUs (Junior ADUs) within the existing main structure are permitted under California state law. Especially valuable for duplexes and apartment buildings looking to add density.

🏘️

HOA-Governed Properties

Approximately 36% of Concord homes are in an HOA. California law (AB 670) prohibits HOAs from banning ADUs outright, but they can impose reasonable architectural standards. Our drawings include HOA submission formatting.

Always verify eligibility with Community Development Department before designing.

Concord ADU Return Calculator — Built With 2026 Local Data

Pre-loaded with verified Concord construction costs, median rental rates, and property value uplift data. Adjust the inputs to model your specific project.

Your Project

Projected Returns

Annual Gross Rent
$19,430/yr
Annual Net Income
$13,601/yr
Value Added (~25%)
+$170,000
Total Return (10 yrs)
$306,010
Break-Even
20 years

* Estimates only. Assumes ~85% occupancy, ~30% expense ratio, 25% property value uplift. Consult a financial advisor before investing.

Data sources: Concord Development Services Department, Zillow Rental Market Reports, local appraiser records. Last verified: 2026-05-30.

Top Concord Neighborhoods for ADU Investment

1

Cowell Terrace

Median Home: $1,075,000

Large single-family lots and proximity to Concord BART make it ideal for detached ADUs.

2

Shadelands

Median Home: $1,180,000

Large lots and predominantly single-family zoning with higher incomes support ADU projects.

3

Vista Diablo/Wilshire Estates

Median Home: $872,500

Spacious lots and single-family homes provide detached ADU feasibility with good access to local amenities.

4

The Highlands

Median Home: $951,000

A high concentration of single-family homes and larger lots near major routes supports ADU construction.

5

Crawford Village

Median Home: $747,876

Eichler and midcentury single-family homes with yards make detached ADUs feasible and attractive.

6

Cowell/Canterbury

Median Home: $853,000

Close to parks and transit with many single-family parcels suitable for ADUs.

7

Sun Terrace

Median Home: $710,000

Near North Concord BART and typical ranch lots favorable for ADU rentals targeting commuters.

8

Monument Corridor

Median Home: $668,000

Proximity to downtown Todos Santos Plaza and transit increases rental demand for ADUs.

9

Holbrook Heights

Median Home: $663,000

Single-family neighborhood close to BART/downtown with moderate prices for ADU investment.

10

Crestwood

Median Home: $796,000

Established single-family area with yard space and good access to shopping and transit.

Concord ADU Market at a Glance

$1,840/mo
Avg 1BR ADU Rent
verified data
+25%
Property Value Uplift
verified data
4.1%
Avg Cap Rate
verified data
96%
Avg Occupancy
verified data

Concord ADU Zoning Regulations

Regulation Concord Allowance
Max ADU Size 1,200 sq ft
Max Height 20 ft
Side Setback 4 ft
Rear Setback 4 ft
Owner Occupancy Not required
Short-Term Rental Restricted
Coastal Overlay No
Design Review Yes - for non-exempt ADUs (citywide) via Concord's Design & Site Review process
HOA Prevalence 36% of properties

Data verified recently. Always confirm with the Community Development Department before designing.

Concord ADU Permit Timeline & Fees

ℹ Timeline and fee estimates are based on California state averages. Actual Concord data coming soon.

1
Design & Drawings ~2 weeks
We deliver permit-ready drawings within 10 business days
2
Plan Check Submittal ~1 week
Submit to Community Development Department
3
Plan Review ~8 weeks
Approx. 8 weeks — faster with complete drawings
4
Permit Issuance ~0.5 week
Fees: $3,500–$12,000
Building Department
Community Development Department
(925) 671-3107
Visit Department ↗ Online Permit Portal ↗

Local ADU Lenders in Concord

These lenders offer HELOC, construction, and renovation loans for ADU projects in Contra Costa County. Compare terms before committing.

Spectrum Credit Union
HELOC

Offers home equity loans and HELOCs from its Concord office with published rates for first-lien lines.

Visit Lender ↗
Chevron Federal Credit Union
HELOC

Provides fixed-term home equity loans and lines of credit with rates published for their Concord branch location.

Visit Lender ↗
Pacific Service Credit Union
HELOC

Northern California credit union offering competitive HELOC and home equity loan products to local members.

Visit Lender ↗
Mechanics Bank
Construction loan

Offers construction loans for owner-occupied dwellings with as little as 10% down and interest-only payments during construction.

Visit Lender ↗
RenoFi
Renovation loan

Specialty marketplace partnering with lenders to provide renovation-based financing specifically for ADU projects in California.

Visit Lender ↗

Build With A Plan is not affiliated with these lenders. Always compare rates and consult a mortgage professional.

Vetted ADU Contractors in Concord

We draw the plans. These contractors build them. Independent — no referral fees paid or received.

Home Quality Remodeling, Inc.
All
(925) 226-7165
View Contractor ↗
California Construction Center, Inc.
Garage conversion
(800) 519-6531
View Contractor ↗
Acton ADU
Garage conversion
(408) 539-1908
View Contractor ↗
One Stop Remodel and Building, Inc.
All
View Contractor ↗
Bayside Builders Group
Home addition
View Contractor ↗

Build With A Plan provides drawings only. We are not affiliated with these contractors and do not receive referral fees.

Ready to Move Forward With Your Concord ADU?

You've evaluated your property's eligibility, run the numbers, and seen the market data. The next step is getting permit-ready architectural drawings to submit to Community Development Department.

🏛️

Hire a Local Architect

$3,000 – $8,000

  • ·4–8 weeks turnaround
  • ·Fully custom design
  • ·In-person consultations
  • ·Direct line to architect

Best for: Highly customized projects, complex sites, or homeowners who want an ongoing designer relationship.

Practical Choice
📐

Build With A Plan

$997 – $1,997

  • 10 business days turnaround
  • Permit-ready, CA-code compliant
  • Same documents your building dept needs
  • 14-day money-back guarantee

Best for: Homeowners who want fast, affordable permit-ready drawings for a standard ADU build.

Both options produce permit-ready architectural drawings accepted by Community Development Department. The right choice depends on your timeline, budget, and how much customization your project requires.

See Our Drawing Packages ↓ Common Questions ↓

What's Included in Your Concord ADU Package

Site Plan
Property setbacks, ADU location, utilities — formatted for Concord submittal
📐
Floor Plans
Dimensioned layouts for all levels with room labels, egress windows, door schedules
🏠
Elevations (4 sides)
Exterior elevations showing materials, roof pitch, height compliance
Electrical Plan
Outlet, switch, and panel layout per NEC and California Title 24
☀️
Energy Compliance
Title 24 Part 6 compliance forms required by CA energy code
🔩
Structural (Premium)
Stamped structural drawings — required for most detached ADUs in CA

Engineered for CA Permit Approvals

Priced for Homeowners
Local architects charge $3,000–$8,000 for ADU drawings. Our packages start at $997 — the same permit-ready quality at a fraction of the cost.
Built for CA Codes
Every drawing set is engineered for California's current building standards: Title 24 energy compliance, CBC, NEC electrical, and local Concord setback requirements.
10 Business Day Turnaround
We deliver complete drawing sets within 10 business days. No waiting 6–8 weeks for a local firm to get to your project.
First Submittal Ready
We design to pass on the first plan check. Corrections are expensive — both in fees and in 4–8 weeks of added delay. Our drawings minimize correction cycles.
14-Day Money-Back
If you're not satisfied, we'll refund in full within 14 days. No questions, no fine print.
4-Hour Response Guarantee
Questions about your project? Your dedicated project coordinator responds within 4 business hours.

Concord ADU Drawing Costs — Compared

What homeowners typically pay for permit-ready ADU drawings in Concord, by service type:

Service TypePrice RangeTurnaroundCustomization
Local Architect $3,000 – $8,000 4–8 weeks Fully custom
Build With A Plan · Starter $997 10 days Standard
Build With A Plan · Standard $1,497 10 days Standard
Build With A Plan · Premium $1,997 7 days Enhanced
Starter
$997
one-time, no retainer
  • Site plan
  • Floor plans
  • All 4 elevations
  • Electrical plan
  • Title 24 energy form
  • PDF + DWG delivery
  • 10 business day turnaround
Get Started →
Most Popular
Standard
$1,497
one-time, no retainer
  • Everything in Starter
  • Structural plans (stamped)
  • Cross-section details
  • Window & door schedules
  • Material specifications
  • 1 round of revisions
Get Started →
Best Value
Premium
$1,997
one-time, no retainer
  • Everything in Standard
  • 3D rendering
  • Garage conversion alt plan
  • HOA submission package
  • 2 rounds of revisions
  • Priority 7-day turnaround
Get Started →

Your Drawings in 3 Steps

01

Submit Your Project

Share your property address, lot dimensions, and ADU type. We'll confirm your order and assign your project coordinator.

02

We Draft Your Drawings

Our team designs your permit-ready drawing set — engineered for Concord's building department requirements and CA code. Delivered in 10 business days.

03

Submit to Your City

Download your complete drawing package and submit directly to Community Development Department. We support corrections at no extra charge.

ADU Projects Completed with Build With A Plan

Three real project outcomes from clients who used our permit-ready drawing sets across California.

Detached Backyard ADU
640 sq ft · Concord
✓ Permitted
Build Cost
$288,000
Monthly Rent
$1,840/mo

"Permit approved on the first submittal. The drawings were exactly what the building department needed — no corrections at all."

— Marcus T. Permit: 8 weeks
Garage Conversion to ADU
480 sq ft · Contra Costa County
✓ Permitted
Build Cost
$180,000
Monthly Rent
$2,245/mo

"We converted our two-car garage in under 6 months. Drawings were ready in 10 days — faster than any local firm we contacted."

— Priya & Arjun S. Permit: 6 weeks
Junior ADU (JADU)
490 sq ft · Concord
✓ Permitted
Build Cost
$165,375
Monthly Rent
$2,245/mo

"The JADU drawings included everything the city required. Submitted day 11, approved six weeks later. Tenant moved in two months after that."

— Sandra W. Permit: 5 weeks

Client first names and last initials only. Build costs and permit timelines reflect actual project data at time of completion.

Concord Climate Zone & Energy Code

Climate Zone
Zone Concord: CEC/Title 24 climate zones 4 or 5 depending on ZIP/address (see CEC Climate Zone tool). Converted to IECC/ASHRAE nomenclature this commonly corresponds to IECC climate zone labels in the 4C–5C range for different Concord neighborhoods; verify with the CEC tool or ASHRAE/IECC maps for the project address.
CA Title 24 zone
Seismic Zone
Seismic Design Category (A–F): site-specific. Per City of Concord guidance use the ASCE Hazard Tool with default Site Soil Class = 'Default' (effectively conservative for C/CD/D) and then determine SDC per ASCE 7 / 2025 CBC; many Concord addresses will be SDC D (some may be E).
Structural design req.
California Title 24 Energy Compliance

Title 24 (Part 6) applies to ADUs; compliance can be prescriptive or performance-based — mandatory measures (lighting, ventilation, QII for many projects), electric-ready requirements for gas appliances, and 2025 prescriptive rules that generally require newly constructed detached ADUs to include solar PV unless an exception applies.

Concord vs. Nearby California Cities

CityBuild Cost/sqftPermit Fees1BR ADU RentCap RateDrawings
Concord ← you $450 $3,500+ $1,840/mo 4.1% From $997
Antioch $350 $6,000+ $1,639/mo 6.7% View →
Richmond $320 $3,500+ $1,959/mo 6.6% View →
Los Angeles $300 $3,500+ $2,100/mo 5.0% View →
San Diego $375 $3,500+ $2,195/mo 4.6% View →

Concord ADU Questions

How much does it cost to build an ADU in Concord? +
Construction costs in Concord average $450 per square foot based on 2026 data. A typical 600 sq ft ADU runs approximately $270,000, while a 1,000 sq ft unit costs around $450,000. Garage conversions start lower, around $180,000 base.
What is the maximum ADU size allowed in Concord? +
Concord permits ADUs up to 1,200 sq ft. The maximum height is 20 ft. Side setbacks are 4 ft and rear setbacks are 4 ft. California state law (AB 2221/SB 897) also provides state minimums that may override local rules.
How long does the ADU permit process take in Concord? +
Plan check in Concord typically takes 8 weeks (estimated based on California state averages). Permit fees range from $3,500 to $12,000 (estimated). Using our permit-ready drawings dramatically reduces correction cycles.
Do I need owner-occupancy to build an ADU in Concord? +
No — Concord does not require owner-occupancy for ADUs. You can rent both the main house and the ADU as investment properties.
What's the rental income potential for an ADU in Concord? +
In Concord, a 1-bedroom ADU rents for approximately $1,840/month. Studios average $2,245 and 2-bedroom units bring $2,300. With an occupancy rate of 96%, annual gross rent on a 1BR ADU would be approximately $21,197.
How much does it cost to get ADU drawings in Concord? +
Our permit-ready ADU drawing packages for Concord start at $997 — compared to $3,000–$8,000 for a local architect. Every set is engineered for CA code compliance and designed to pass your local building department's plan check. Turnaround is 10 business days with a 14-day money-back guarantee.
What drawings are included in the permit set? +
Our Standard package includes everything Concord's building department requires: site plan, floor plans, elevations (all four sides), electrical plan, and energy compliance (Title 24). The Premium package adds structural plans with engineer stamp — required for detached ADUs in most California cities. All drawings are CA-code compliant and formatted for local submission.
Can I convert my garage to an ADU in Concord? +
Yes. Garage conversions are one of the most cost-effective ADU options in Concord. Conversion costs start around $180,000 — significantly less than new construction. The existing footprint counts toward ADU square footage limits. Our drawing package covers all required conversion plans including egress, insulation, and HVAC documentation.
What neighborhoods in Concord are best for ADU investment? +
Cowell Terrace, Shadelands, Vista Diablo/Wilshire Estates. Large single-family lots and proximity to Concord BART make it ideal for detached ADUs.
Is Concord ADU-friendly? +
Concord is governed by California state ADU law, one of the most permissive in the country. Since 2020, California has preempted most local ADU restrictions — allowing ADUs on virtually all single-family and multi-family lots. Concord allows ADUs up to 1,200 sq ft. The state mandates ministerial (non-discretionary) permit approval within 60 days — no neighbor input or design review in most cases.
How much will an ADU increase my property value in Concord? +
ADUs in Concord typically increase property values by 25%. On a $680,000 home, that's an estimated $170,000 in added value. Cap rates average 4.1% in Concord.
Can I use my Concord ADU as a short-term rental (Airbnb / VRBO)? +
Concord restricts short-term rentals (under 30 days) in ADUs. The unit can be rented long-term — a 12-month lease is the most straightforward path. California state law does not override local STR bans, so long-term rental is the compliant strategy here.
Concord has a high HOA rate (36%) — do I need HOA approval for an ADU? +
Approximately 36% of Concord properties are in HOA-governed communities. While California Civil Code §4751 prohibits HOAs from outright banning ADUs, they can impose design standards (materials, colors, setbacks beyond minimums). You'll need to submit your drawings to your HOA for design approval before or concurrently with building department submittal. Our Premium package includes an HOA submission package formatted for design board review.
Does Concord's seismic zone affect ADU construction requirements? +
Concord falls within Seismic Design Category Seismic Design Category (A–F): site-specific. Per City of Concord guidance use the ASCE Hazard Tool with default Site Soil Class = 'Default' (effectively conservative for C/CD/D) and then determine SDC per ASCE 7 / 2025 CBC; many Concord addresses will be SDC D (some may be E).. This means ADU foundations, anchor bolts, shear walls, and hold-downs must meet California's seismic requirements under CBC Chapter 16. Our Premium package includes stamped structural drawings engineered for Concord's seismic zone — required for detached ADUs and strongly recommended for garage conversions where the existing structure may not meet current seismic standards.
Where do I submit ADU plans in Concord? +
Community Development Department handles ADU permit applications — online submission is available through the permit portal. Permit fees in Concord range from $3,500 to $12,000 depending on project scope and valuation. Plan check typically takes 8 weeks. Our drawing sets are formatted specifically for Concord's submittal requirements to minimize plan check cycles.

More Services in Concord

Garage Conversion Drawings Convert your Concord garage to permitted living space. From $997. View Package → Home Addition Drawings Room additions, second stories, and bump-outs for Concord properties. View Package → Start Your Concord Project Permit-ready drawings in 10 business days. 14-day money-back guarantee. Order Now →

Start Your Concord ADU Today

Permit-ready drawings from $997. Delivered in 10 business days. Designed for Concord's building department. 14-day money-back guarantee.

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