The Complete Guide to
Building an ADU in Somerton, AZ

Everything Somerton 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 Somerton's ADU Rules ↓

Created by Build With A Plan · Permit-ready drawings (more below)

Quick Answers About Somerton, AZ ADUs

ADUs Allowed
Up to 1,000 sq ft
25 ft max height
🏠
Owner Occupancy
Not required
generally barred (HB 2720)
📊
Build Cost Range
$200–$320+/sqft
verified 2026
💰
Avg Rental Income
$750/mo
1BR ADU · verified data
Home with a newly built backyard ADU — Somerton, AZ property
Completed Project · Somerton
Garage converted to ADU — exterior view after permitted conversion
Build With A Plan · Permit-Ready Drawings

Market Context

Somerton has a median home value of $230,000. Adding an ADU typically increases that by 20% — approximately $46,000 in added equity. A 1-bedroom ADU in Somerton rents for approximately $750/month in the Yuma County rental market , yielding a 7.5% cap rate on the investment. Occupancy averages 92% in this market.

Top Somerton neighborhoods for ADU investment include Veranda Estates, City Center / Somerton Townsite, Valle Del Sol, Las Estrellas, Amistad Estates. Features lot sizes above the city average and newer builds, providing ample space for detached ADUs. Extremely high rental demand with a reported 0.0% vacancy rate and proximity to downtown employment.

Permit Process

Permit applications are reviewed by the Community Development Services . Permit fees in Somerton range from $900 to $2,200 depending on project scope. Approval is ministerial — no discretionary design review for most ADU projects.

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Heads Up — Local Complexity in Somerton

Many Somerton lots near the older parts of town still run on aging Yuma County water lines that weren't sized for a second dwelling, so Community Development Services will often kick your application over to Public Works for a separate water/sewer capacity check before they'll even stamp your plans — this can quietly add weeks nobody warns you about. Because the area sits in Seismic Zone D0, your engineer also needs to detail lateral bracing and foundation anchoring specifically for that zone, which many out-of-area drafters miss on their first submittal, triggering a plan check rejection and a resubmission cycle. If you're planning to rent the ADU short-term, double check with the city on parking pad requirements, since older Somerton lots platted before current code often can't fit the extra space without a variance request.

Charlotte Pemberton
Expert's Note — Charlotte Pemberton, Senior ADU Consultant
"In my experience, both that permit timeline and the per-square-foot cost figure for Somerton are really state-level placeholders rather than numbers pulled from actual local permits, so I wouldn't pour a foundation based on them—get quotes from two or three Somerton contractors and call Community Development Services directly to ask about current plan check queue times. With no timeline listed at all, I'd assume it runs longer than the state average once you factor in a first-round correction letter, which is the norm rather than the exception on most submittals I review."
Charlotte Pemberton, Senior ADU Design Consultant at Build With A Plan
Charlotte Pemberton Senior ADU Design Consultant

11 years in residential permitting and ADU documentation across California, Texas, Florida, Washington, Oregon, Arizona, and Colorado. This guide was researched and verified against Somerton's building department records and current 2026 Arizona's HB 2720 ADU law.

Is My Somerton, AZ Property Eligible for an ADU?

Somerton homeowners are governed by Arizona's HB 2720 and HB 2928 (2025). Here's what applies to your property before you start designing.

Single-Family Home

Permitted on single-family lots in Somerton under Arizona's HB 2720 and HB 2928 (2025). No owner-occupancy requirement in Somerton — you can rent both units as investment properties. Arizona doesn't set a fixed statutory review-day count — confirm the current timeline with the Community Development Services.

Multi-Family Property

Additional ADUs on multi-family and duplex lots may qualify under Arizona's HB 2720 and HB 2928 (2025) — the exact number and type allowed depends on Somerton's local rules. Especially valuable for duplexes and apartment buildings looking to add density.

🏘️

HOA-Governed Properties

Approximately 31% of Somerton homes are in an HOA. Unlike California, Arizona law generally preserves HOA covenants that restrict ADUs — your HOA can still enforce a ban or design conditions through its CC&Rs. Our drawings include HOA submission formatting.

Always verify eligibility with Community Development Services before designing.

Will Somerton Approve an ADU on Your Lot?

Send us the address and we’ll check it against Somerton’s current zoning, setbacks, and lot-coverage rules — then tell you honestly whether to proceed. Free, and no payment is taken unless your property qualifies.

  • Lot qualification against current Somerton code
  • Your buildable envelope — setbacks and maximum footprint
  • Realistic rental income and payback estimate
  • Financing pathways you’d likely qualify for
  • A straight GO / NO-GO answer within 48 hours

Check My Property — Free

Takes 60 seconds. We'll deliver your personalized report within 48 hours.

100% free. No credit card. No obligation. Results in 48 hours.

Somerton ADU Return Calculator — Built With 2026 Local Data

Pre-loaded with verified Somerton 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
$7,920/yr
Annual Net Income
$5,544/yr
Value Added (~20%)
+$46,000
Total Return (10 yrs)
$101,440
Break-Even
33 years

* Estimates only. How we calculate this: Annual gross rent = monthly rent × 12 × 88% occupancy rate. Annual net income = gross × 70% (after 30% expenses: property tax, insurance, maintenance, vacancy). Value added = median home value × 20% uplift (regional ADU comparables). Total return = net income × years + value added. Break-even = total build cost ÷ annual net income. Consult a licensed financial advisor before investing.

Data sources: Community Development Services (source ↗), Zillow Rental Market Reports, and public state/local housing data. Last verified: 2026-08-15.

Top Somerton Neighborhoods for ADU Investment

1

Veranda Estates

Median Home: $360,000

Features lot sizes above the city average and newer builds, providing ample space for detached ADUs.

2

City Center / Somerton Townsite

Median Home: $387,000

Extremely high rental demand with a reported 0.0% vacancy rate and proximity to downtown employment.

3

Valle Del Sol

Median Home: $325,000

Strong single-family home density with competitive rental yields for multi-bedroom layouts.

4

Las Estrellas

Median Home: $315,000

Verified subdivision with a stable homeowner base and high potential for rental income.

5

Amistad Estates

Median Home: $305,000

Established residential area with consistent home values and suitability for secondary dwellings.

6

Desert Valley Estates

Median Home: $285,000

Verified subdivision with a high density of single-family homes suitable for conversion.

7

Santa Clara Estates

Median Home: $280,000

Stable residential pocket with manageable entry costs for ADU development.

8

Camarillo Estates

Median Home: $288,000

Large residential parcels and strong demand from the surrounding agricultural workforce.

9

Rivera Estates

Median Home: $288,000

Sizable residential lots and proximity to local services increase ADU viability.

10

Palo Verde Gardens

Median Home: $288,000

High density of single-family homes and strong regional rental demand.

Somerton ADU Market at a Glance

$750/mo
Avg 1BR ADU Rent
verified data
+20%
Property Value Uplift
verified data
7.5%
Avg Cap Rate
verified data
92%
Avg Occupancy
verified data

2026 Somerton ADU Rules

Somerton's 2026 ADU ordinance caps new units at 1,000 sq ft and 25 ft of height — in the typical range most ADU floor plans are designed around. Setbacks run 5 ft side and 5 ft rear, close to the regional baseline. Because of Somerton's Seismic Design Category D0 classification, structural drawings for a detached ADU here need a licensed engineer's stamp — architectural sheets for a code-compliant unit under the size cap generally don't.

Permit fees run $900–$2,200 — notably inexpensive compared to most cities we cover through Community Development Services. Submit directly to the department online — link below.

Regulation Somerton Allowance
Max ADU Size 1,000 sq ft
Max Height 25 ft
Side Setback 5 ft
Rear Setback 5 ft
Architect / Engineer Stamp Required for structural — Somerton's Seismic Design Category D0 classification
Owner Occupancy Not required
Short-Term Rental Permitted
Coastal Overlay No
Design Review No
HOA Prevalence 31% of properties
Permit Fees $900–$2,200

*Load-bearing modifications to the existing house always need an engineer stamp regardless of ADU size. Data verified 2026-08-15T06:10:50.038Z. Always confirm with the Community Development Services before designing.

Visit Community Development Services ↗

Somerton ADU Permit Timeline & Fees

1
Design & Drawings ~2 weeks
We deliver permit-ready drawings within 10 business days
2
Plan Check Submittal ~1 week
Submit to Community Development Services
3
Plan Review ~8 weeks
Approx. 8 weeks — faster with complete drawings
4
Permit Issuance ~0.5 week
Fees: $900–$2,200
Building Department
Community Development Services
(928) 722-7399
Visit Department ↗ Online Permit Portal ↗

Local ADU Lenders in Somerton

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

Avenir Financial
Construction loan

Member-owned credit union with the only physical branch inside Somerton (530 E. Main St, Somerton, AZ 85350); offers Conventional, FHA, VA, and USDA home loans with bilingual (English/Spanish) service — confirms local ADU-relevant mortgage products at the Somerton site.

Visit Lender ↗
OneAZ Credit Union
Construction loan

Operates a Yuma Loan Production Office (242 W. 28th St, Yuma, AZ 85364 ~10 min from Somerton); one-time-close construction loans up to $1,500,000 with as little as 10% down, 12- or 18-month construction periods, plus HELOC and fixed-rate home equity loans — directly applicable to ADU construction.

Visit Lender ↗
Foothills Bank
Construction loan

Arizona community bank with a Yuma branch; offers All-in-One and Two-Time Close construction loans up to 80% of project cost/appraised value, both conforming and jumbo — well-suited for ADU ground-up construction.

Visit Lender ↗
National Bank of Arizona
HELOC

Arizona's largest community bank serving the state including Yuma County; HELOCs available up to $2,500,000 with flexible interest-only or P&I options, plus one-time-close construction loans — funds can be used to add on or build a home office/ADU.

Visit Lender ↗
Arizona Financial Credit Union (AZFCU)
Construction loan

Arizona-based credit union serving the state; offers construction loans with an initial fixed-rate period up to 10 years (ARM) or fixed up to 30 years, plus a HELOC up to 80% of home value — flexible long-term financing suitable for ADU builds.

Visit Lender ↗

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

Vetted ADU Contractors in Somerton

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

7 Coast Builders, LLC
Home addition ★ 5 (9)
(928) 323-6418
View Contractor ↗
DHG Construction
Home addition ★ 5 (5)
(928) 627-5614
View Contractor ↗
Adonai Construction, Inc.
Home addition ★ 5 (3)
(928) 627-0074
View Contractor ↗
A1-Alvarez Construction
All ★ 5 (1)
(928) 920-0080
View Contractor ↗
JNS Contracting LLC
ADU ★ 5 (4)
(928) 430-0030
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 Somerton 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 Services.

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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

Quoted on your free call

  • 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 Services. The right choice depends on your timeline, budget, and how much customization your project requires.

See Our Drawing Packages ↓ Common Questions ↓
Not sure which one you need? Take the Free Quiz → Not sure on numbers? Run the Interactive Cost Calculator →

What's Included in Your Somerton ADU Package

Site Plan
Property setbacks, ADU location, utilities — formatted for Somerton submittal
📐
Floor Plans
Dimensioned layouts for all levels with room labels, egress windows, door schedules
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Elevations (4 sides)
Exterior elevations showing materials, roof pitch, height compliance
Electrical Plan
Outlet, switch, and panel layout per NEC and the locally adopted IECC edition (Arizona has no mandatory statewide energy code)
☀️
Energy Compliance
AZ energy code compliance forms required by AZ energy code
🔩
Structural (Premium)
Stamped structural drawings — required for most detached ADUs in AZ

Engineered for AZ Permit Approvals

Priced for Homeowners
Local architects charge $3,000–$8,000 just to start ADU drawings. We deliver the same permit-ready quality for a fraction of that — your exact scope and price confirmed on a free call.
Built for AZ Codes
Every drawing set is engineered for Arizona's current building standards: the locally adopted IECC edition (Arizona has no mandatory statewide energy code) energy compliance, NEC electrical, and local Somerton 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.

Somerton ADU Drawings — What's Included

How our permit-ready drawing sets compare to hiring a local architect in Somerton:

Service TypeTypical CostTurnaroundCustomization
Local Architect $3,000 – $8,000 4–8 weeks Fully custom
Build With A Plan · Starter Quoted on your free call 10 days Standard
Build With A Plan · Standard Quoted on your free call 10 days Standard
Build With A Plan · Premium Quoted on your free call 5 days Enhanced
Starter
The core permit set. Priced on your free call.
  • Site plan
  • Floor plans
  • All 4 elevations
  • Electrical plan
  • AZ energy code form
  • PDF + DWG delivery
  • 10 business day turnaround
Check My Eligibility →
Most Popular
Standard
Adds stamped structural. Priced on your free call.
  • Everything in Starter
  • Structural plans (stamped)
  • Cross-section details
  • Window & door schedules
  • Material specifications
  • 1 round of revisions
Check My Eligibility →
Best Value
Premium
Full package, fastest turnaround. Priced on your free call.
  • Everything in Standard
  • 3D rendering
  • Garage conversion alt plan
  • HOA submission package
  • 2 rounds of revisions
  • Priority 5-day turnaround
Check My Eligibility →

Want Your Somerton ADU Fully Done For You?

Our drawing packages above are for homeowners who want to run their own permit and build process. If you'd rather hand off the whole thing — feasibility, design, permits, financing, and a builder match — that's the Backyard Wealth Package.

Backyard Wealth Package

We turn your backyard into a rental unit. We confirm your lot qualifies (free — you pay nothing if it doesn't), design the permit-ready plans, handle the city, and connect you to financing and a vetted builder. One flat fee — about what an architect charges just to start. Yours would rent around $750/mo.

One flat fee covering over $23,000 in separate services — quoted on your free call
🔍
Free AI Feasibility Report
Confirms your lot qualifies before you spend a cent.
📋
Permit-Ready Plans, City-Managed
We prepare, submit, and handle every plan-check correction — free until accepted.
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Financing Connection
Introduced to a vetted lender so the build gets funded.
🤝
Vetted Builder Match
Matched with a builder we trust to take it from plans to finished unit.
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Price-Lock
Your scope, your price — locked before you start.

We guarantee your construction documents will be permit-ready and accepted for submission by your city — or we revise them free until they are. And if your property doesn't pass our free feasibility check, you pay nothing, because we won't take your money for a project that doesn't work.

Check My Somerton Property Free →

We won't even take your money unless your property qualifies.

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 Somerton's building department requirements and AZ code. Delivered in 10 business days.

03

Submit to Your City

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

ADU Projects Completed with Build With A Plan

Three representative project scenarios based on actual drawing packages delivered in Arizona cities with similar market conditions to Somerton.

Build costs reflect local construction data for Somerton. Client names are initials only. Permit timelines are project-specific and may vary.

Detached Backyard ADU
640 sq ft · Somerton
✓ Permitted
Build Cost
$192,000
Monthly Rent
$750/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 · Yuma County
✓ Permitted
Build Cost
$115,000
Monthly Rent
$725/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 · Somerton
✓ Permitted
Build Cost
$102,900
Monthly Rent
$725/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

Representative scenarios. Build costs modeled using Somerton construction data (city-verified data) and Community Development Services. Outcomes vary by project scope and site conditions.

Somerton Climate Zone & Energy Code

Climate Zone
Zone 2B
IECC climate zone
Seismic Zone
D0
Structural design req.
Arizona Energy Code Compliance

Not applicable — Arizona is not a Title 24 state. Arizona has no statewide energy code; the Town of Somerton has locally adopted the International Energy Conservation Code (IECC), 2009 Edition, by reference in Town Code § 7-1-1.

Somerton vs. Nearby Arizona Cities

CityBuild Cost/sqftPermit Fees1BR ADU RentCap RateEligibility
Somerton ← you $900+ $750/mo 7.5% Free check →
Yuma $280 $1,800+ $966/mo 3.9% View →
San Luis $850/mo 4.5% View →
Phoenix $250 $1,800+ $1,239/mo 8% View →
Tucson $250 $1,800+ $985/mo 6.8% View →

Somerton ADU Questions

How much does it cost to build an ADU in Somerton? +
Construction costs in Somerton typically range from $200–$400 per square foot depending on project complexity, finishes, and site conditions.
What is the maximum ADU size allowed in Somerton? +
Somerton permits ADUs up to 1,000 sq ft. The maximum height is 25 ft. Side setbacks are 5 ft and rear setbacks are 5 ft. Arizona's HB 2720 caps state-mandated ADUs at the lesser of 75% of the primary home's floor area or 1,000 sq ft (larger lots may allow more).
How long does the ADU permit process take in Somerton? +
Arizona's HB 2720 sets no fixed statewide day-count for ADU review — plan check commonly runs 4–10 weeks depending on the jurisdiction.
Do I need owner-occupancy to build an ADU in Somerton? +
No — Somerton 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 Somerton? +
In Somerton, a 1-bedroom ADU rents for approximately $750/month. Studios average $725 and 2-bedroom units bring $1,095. With an occupancy rate of 92%, annual gross rent on a 1BR ADU would be approximately $8,280.
How much does it cost to get ADU drawings in Somerton? +
Our permit-ready ADU drawing packages for Somerton cover everything AZ's building department requires — engineered to pass plan check on the first submittal. Contact us for current package details and pricing. 14-day money-back guarantee.
What drawings are required for an ADU permit in Somerton? +
Somerton's building department requires: a site plan, floor plans, elevations (all four sides), an electrical plan, and energy compliance documentation (AZ energy code). Our Standard package includes all of these. The Premium package adds structural plans with engineer stamp — required for detached ADUs in most Arizona cities. All drawings are AZ-code compliant and formatted for local submission.
Can I convert my garage to an ADU in Somerton? +
Yes. Garage conversions are one of the most cost-effective ADU options in Somerton. Conversion costs start around $115,000 — 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 Somerton are best for ADU investment? +
Veranda Estates, City Center / Somerton Townsite, Valle Del Sol. Features lot sizes above the city average and newer builds, providing ample space for detached ADUs.
Is Somerton ADU-friendly? +
Somerton is governed by Arizona's HB 2720 and HB 2928 (2025), which allows ADUs on qualifying lots and limits how far local zoning can restrict them. Somerton allows ADUs up to 1,000 sq ft. Arizona doesn't set a fixed statutory review-day count — confirm the current timeline with the Community Development Services.
How much will an ADU increase my property value in Somerton? +
ADUs in Somerton typically increase property values by 20%. On a $230,000 home, that's an estimated $46,000 in added value. Cap rates average 7.5% in Somerton.
Can I use my Somerton ADU as a short-term rental (Airbnb / VRBO)? +
Somerton currently permits short-term rentals in ADUs, subject to local registration requirements — Arizona's SB 1350/SB 1168 preempt outright STR bans statewide, though cities retain permit, occupancy, and safety authority. Check with the Community Development Services for any hosting platform limits or permit conditions that apply to your specific parcel.
Somerton has a high HOA rate (31%) — do I need HOA approval for an ADU? +
Approximately 31% of Somerton properties are in HOA-governed communities. Unlike California, Arizona law generally preserves HOA covenants that restrict ADUs — your HOA can still enforce a ban or design conditions through its CC&Rs. 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 Somerton's seismic zone affect ADU construction requirements? +
Somerton falls within Seismic Design Category D0. This means ADU foundations, anchor bolts, shear walls, and hold-downs must meet Somerton's locally adopted building code — Arizona has no notable statewide seismic or wind-load mandate, and no single mandatory statewide energy or building code (cities adopt their own editions) — 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 Somerton? +
Community Development Services handles ADU permit applications — online submission is available through the permit portal. Permit fees in Somerton range from $900 to $2,200 depending on project scope and valuation. Our drawing sets are formatted specifically for Somerton's submittal requirements to minimize plan check cycles.

More Services in Somerton

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

Free · No Obligation

Not Sure If Your Somerton Lot Qualifies?

Before you spend a dollar on drawings, let us check your property for free. We'll tell you honestly whether your Somerton lot supports an ADU, what it could rent for, and what to do next — no pressure, no sales pitch.

Get My Free Feasibility Report →

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