The Complete Guide to
Building an ADU in San Bernardino, CA

Everything San Bernardino 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 San Bernardino's ADU Rules ↓

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

Quick Answers About San Bernardino, CA ADUs

ADUs Allowed
Up to 800 sq ft
16 ft max height
🏠
Owner Occupancy
Not required
CA state law applies
📊
Average Build Cost
$300/sqft
verified 2026
💰
Avg Rental Income
$1,495/mo
1BR ADU · verified data
California home with a newly built backyard ADU — San Bernardino property
Completed Project · San Bernardino
Garage converted to ADU — exterior view after permitted conversion
Build With A Plan · Permit-Ready Drawings from $997

Market Context

San Bernardino has a median home value of $362,000. Adding an ADU typically increases that by 25.0% — approximately $90,500 in added equity. A 1-bedroom ADU in San Bernardino rents for approximately $1,495/month in the San Bernardino County rental market , yielding a 3.9% cap rate on the investment. Occupancy averages 97.0% in this market.

Top San Bernardino neighborhoods for ADU investment include Verdemont, Ridgeline, Arrowhead Farms, North Park, Kendall. Very large lots and higher home values make Verdemont ideal for detached ADUs and rentable units. Large-lot foothill neighborhood with space for detached ADUs and strong owner-occupancy rates.

Permit Process

Permit applications are reviewed by the Building & Safety Division , with a plan check timeline of approximately 8 weeks. Permit fees in San Bernardino range from $3,500 to $12,000 depending on project scope. Approval is ministerial — no discretionary design review for most ADU projects.

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 San Bernardino's building department records and current 2026 California ADU law.

Is My San Bernardino, CA Property Eligible for an ADU?

San Bernardino 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 San Bernardino under California state law. No owner-occupancy requirement in San Bernardino — 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 31% of San Bernardino 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 Building & Safety Division before designing.

San Bernardino ADU Return Calculator — Built With 2026 Local Data

Pre-loaded with verified San Bernardino 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
$15,787/yr
Annual Net Income
$11,051/yr
Value Added (~25.0%)
+$90,500
Total Return (10 yrs)
$201,010
Break-Even
17 years

* Estimates only. Assumes ~85% occupancy, ~30% expense ratio, 25.0% property value uplift. Consult a financial advisor before investing.

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

Top San Bernardino Neighborhoods for ADU Investment

1

Verdemont

Median Home: $621,145

Very large lots and higher home values make Verdemont ideal for detached ADUs and rentable units.

2

Ridgeline

Median Home: $642,444

Large-lot foothill neighborhood with space for detached ADUs and strong owner-occupancy rates.

3

Arrowhead Farms

Median Home: $464,186

Suburban lots and family housing density support detached ADUs and long-term rentals.

4

North Park

Median Home: $561,016

Established single-family blocks near job corridors good for ADU rentals.

5

Kendall

Median Home: $535,325

High single-family home concentration and solid resale values support ADU investment.

6

Cimmeron

Median Home: $540,642

Mid-to-high median values and neighborhood lot patterns suitable for ADUs.

7

Hudson

Median Home: $496,838

Moderate-priced single-family areas with rental demand and ADU feasibility.

8

Cajon

Median Home: $489,787

Mix of lot sizes and proximity to regional corridors supports rental demand for ADUs.

9

Muscoy

Median Home: $454,153

Lower median values and larger lots in parts of Muscoy make conversion to ADUs economical.

10

University

Median Home: $401,590

Closest neighborhood to CSUSB with strong student rental demand for ADUs or JADUs.

San Bernardino ADU Market at a Glance

$1,495/mo
Avg 1BR ADU Rent
verified data
+25.0%
Property Value Uplift
verified data
3.9%
Avg Cap Rate
verified data
97.0%
Avg Occupancy
verified data

San Bernardino ADU Zoning Regulations

Regulation San Bernardino Allowance
Max ADU Size 800 sq ft
Max Height 16 ft
Side Setback 4.0 ft
Rear Setback 4.0 ft
Owner Occupancy Not required
Short-Term Rental Restricted
Coastal Overlay No
Design Review No
HOA Prevalence 31% of properties

Data verified recently. Always confirm with the Building & Safety Division before designing.

San Bernardino ADU Permit Timeline & Fees

ℹ Timeline and fee estimates are based on California state averages. Actual San Bernardino 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 Building & Safety Division
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
Building & Safety Division
(909) 998-2230
Visit Department ↗ Online Permit Portal ↗

Local ADU Lenders in San Bernardino

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

Arrowhead Credit Union
HELOC

Offers home equity loans and HELOCs (fixed-rate home equity loan option); membership and underwriting required—serves San Bernardino area.

Visit Lender ↗
California Bank & Trust
Construction loan

Offers one-time-close construction-to-permanent loans and home equity/HELOC products—regional bank serving Southern California suitable for ADU construction financing.

Visit Lender ↗
RenoFi (fintech renovation lending platform)
Renovation loan

Renovation-specific lending platform that partners with credit unions nationwide to deliver renovation/ADU financing; has enabled thousands of renovation loans.

Visit Lender ↗
Neighborhood Partnership Housing Services (NPHS)
Construction loan

Inland Empire CDFI providing factory-built ADU financing and local ADU loan/grant programs (program examples show ADU loans up to ~$200k and ADU grant support).

Visit Lender ↗
Pacific Premier Bank
HELOC

Regional bank with branches in San Bernardino that offers home equity and construction lending products (home-equity/HELOC and construction loan capabilities).

Visit Lender ↗

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

Vetted ADU Contractors in San Bernardino

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

TRIFORCE BUILD
ADU
View Contractor ↗
JG & SONS CONSTRUCTION
Garage conversion
View Contractor ↗
JRD CONSTRUCCION
All
(909) 562-9800
View Contractor ↗
H5 CONSTRUCTION
All
View Contractor ↗
Burke Construction
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 San Bernardino 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 Building & Safety Division.

🏛️

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 Building & Safety Division. 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 San Bernardino ADU Package

Site Plan
Property setbacks, ADU location, utilities — formatted for San Bernardino 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 San Bernardino 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.

San Bernardino ADU Drawing Costs — Compared

What homeowners typically pay for permit-ready ADU drawings in San Bernardino, 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 San Bernardino'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 Building & Safety Division. 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 · San Bernardino
✓ Permitted
Build Cost
$192,000
Monthly Rent
$1,495/mo

"Drawings were ready on day 9. I submitted to the city the same week. The reviewer called them the cleanest ADU set he'd seen in months."

— Jerome H. Permit: 8 weeks
Garage Conversion to ADU
480 sq ft · San Bernardino County
✓ Permitted
Build Cost
$120,000
Monthly Rent
$1,350/mo

"Our garage conversion is now renting at $1,850/month. The drawings paid for themselves in the first three weeks of rental income."

— Miguel R. Permit: 6 weeks
Junior ADU (JADU)
490 sq ft · San Bernardino
✓ Permitted
Build Cost
$110,250
Monthly Rent
$1,350/mo

"Our JADU was the easiest part of the whole project. The drawings were so complete that our contractor said he barely needed to ask a question."

— Thomas & Ana B. Permit: 5 weeks

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

San Bernardino Climate Zone & Energy Code

Climate Zone
Zone 3B
CA Title 24 zone
Seismic Zone
D (site-dependent; may be E or F)
Structural design req.
California Title 24 Energy Compliance

ADUs in California must comply with the California Building Energy Efficiency Standards (Title 24, Part 6), meeting mandatory envelope, HVAC, lighting, and ventilation requirements, as well as 2022 code mandates for energy storage readiness and rooftop solar PV.

San Bernardino vs. Nearby California Cities

CityBuild Cost/sqftPermit Fees1BR ADU RentCap RateDrawings
San Bernardino ← you $300 $3,500+ $1,495/mo 3.9% From $997
Fontana $325 $1,447+ $1,837/mo 4.4% View →
Ontario $300 $15,442+ $1,934/mo 4.8% View →
Rancho Cucamonga $250 $3,500+ $2,148/mo 4.2% View →
Victorville $400 $3,500+ $1,190/mo 3.8% View →

San Bernardino ADU Questions

How much does it cost to build an ADU in San Bernardino? +
Construction costs in San Bernardino average $300 per square foot based on 2026 data. A typical 600 sq ft ADU runs approximately $180,000, while a 1,000 sq ft unit costs around $300,000. Garage conversions start lower, around $120,000 base.
What is the maximum ADU size allowed in San Bernardino? +
San Bernardino permits ADUs up to 800 sq ft. The maximum height is 16 ft. Side setbacks are 4.0 ft and rear setbacks are 4.0 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 San Bernardino? +
Plan check in San Bernardino 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 San Bernardino? +
No — San Bernardino 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 San Bernardino? +
In San Bernardino, a 1-bedroom ADU rents for approximately $1,495/month. Studios average $1,350 and 2-bedroom units bring $1,995. With an occupancy rate of 97.0%, annual gross rent on a 1BR ADU would be approximately $17,402.
How much does it cost to get ADU drawings in San Bernardino? +
Our permit-ready ADU drawing packages for San Bernardino 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 San Bernardino'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 San Bernardino? +
Yes. Garage conversions are one of the most cost-effective ADU options in San Bernardino. Conversion costs start around $120,000 — 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 San Bernardino are best for ADU investment? +
Verdemont, Ridgeline, Arrowhead Farms. Very large lots and higher home values make Verdemont ideal for detached ADUs and rentable units.
Is San Bernardino ADU-friendly? +
San Bernardino 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. San Bernardino allows ADUs up to 800 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 San Bernardino? +
ADUs in San Bernardino typically increase property values by 25.0%. On a $362,000 home, that's an estimated $90,500 in added value. Cap rates average 3.9% in San Bernardino.
Can I use my San Bernardino ADU as a short-term rental (Airbnb / VRBO)? +
San Bernardino 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.
San Bernardino has a high HOA rate (31%) — do I need HOA approval for an ADU? +
Approximately 31% of San Bernardino 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 San Bernardino's seismic zone affect ADU construction requirements? +
San Bernardino falls within Seismic Design Category D (site-dependent; may be E or F). 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 San Bernardino'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 San Bernardino? +
Building & Safety Division handles ADU permit applications — online submission is available through the permit portal. Permit fees in San Bernardino 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 San Bernardino's submittal requirements to minimize plan check cycles.

More Services in San Bernardino

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

Start Your San Bernardino ADU Today

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

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Questions? Your coordinator responds within 4 business hours.