The Complete Guide to
Building an ADU in Pasco, WA

Everything Pasco 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 Pasco's ADU Rules ↓

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

Quick Answers About Pasco, WA ADUs

ADUs Allowed
Up to 1,000 sq ft
25 ft max height
🏠
Owner Occupancy
Not required
CA state law applies
📊
Average Build Cost
$300/sqft
verified 2026
💰
Avg Rental Income
$1,277/mo
1BR ADU · verified data
Modern detached ADU in a California backyard — completed project in Pasco
Completed Project · Pasco
Interior of a permitted ADU studio unit — open-plan living and kitchen
Build With A Plan · Permit-Ready Drawings from $997

Market Context

Pasco has a median home value of $330,000. Adding an ADU typically increases that by 28% — approximately $92,400 in added equity. A 1-bedroom ADU in Pasco rents for approximately $1,277/month in the Franklin County rental market , yielding a 5.3% cap rate on the investment. Occupancy averages 97% in this market.

Top Pasco neighborhoods for ADU investment include West Pasco, Downtown Pasco, Columbia Park / Riverfront area, North Pasco (Road 68 / Road 72 corridor), South/West Suburban Pasco (Argent / Enzian area). High single‑family density, larger lots and higher home values with strong buyer/renter interest make this ideal for detached ADUs. Close to jobs and amenities downtown producing strong rental demand and easy walkable access for ADU tenants.

Permit Process

Permit applications are reviewed by the Building Division , with a plan check timeline of approximately 1.2 weeks. Permit fees in Pasco range from $8,429 to $13,905 depending on project scope. Design review: Yes - in historic districts only

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

Is My Pasco, WA Property Eligible for an ADU?

Pasco 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 Pasco under California state law. No owner-occupancy requirement in Pasco — 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 8% of Pasco 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.

🏛️

Historic Districts

Yes - in historic districts only

Always verify eligibility with Building Division before designing.

Pasco ADU Return Calculator — Built With 2026 Local Data

Pre-loaded with verified Pasco 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
$13,485/yr
Annual Net Income
$9,440/yr
Value Added (~28%)
+$92,400
Total Return (10 yrs)
$186,800
Break-Even
20 years

* Estimates only. Assumes ~85% occupancy, ~30% expense ratio, 28% property value uplift. Consult a financial advisor before investing.

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

Top Pasco Neighborhoods for ADU Investment

1

West Pasco

Median Home: $490,000

High single‑family density, larger lots and higher home values with strong buyer/renter interest make this ideal for detached ADUs.

2

Downtown Pasco

Median Home: $428,995

Close to jobs and amenities downtown producing strong rental demand and easy walkable access for ADU tenants.

3

Columbia Park / Riverfront area

Median Home: $430,000

Desirable riverfront-adjacent area with existing single‑family homes and year‑round rental appeal.

4

North Pasco (Road 68 / Road 72 corridor)

Median Home: $428,995

Suburban single‑family neighborhoods with larger lot footprints suitable for detached ADUs and steady rental demand.

5

South/West Suburban Pasco (Argent / Enzian area)

Median Home: $435,000

Newer single‑family subdivisions with buildable rear yards and homeowner interest in rental income.

6

Road 100 / Newer Subdivisions Corridor

Median Home: $430,000

Rapidly built single‑family neighborhoods with lot sizes and market demand that favor detached ADUs.

7

Columbia Basin College (CBC) / East Pasco area

Median Home: $400,000

Close proximity to Columbia Basin College increases student/employee rental demand for ADUs.

8

Silver Mound / Buckingham / Enzian clusters

Median Home: $435,000

Established residential pockets with family homes on lots often large enough for detached ADUs.

9

Historic Pasco / Near 3rd Ave neighborhoods

Median Home: $415,000

Older single‑family parcels near downtown with good rental demand and potential for conversions or detached ADUs.

10

Road 54 / Road 59 outskirts (large‑lot suburban)

Median Home: $420,000

Larger lots on the city edge that are some of the easiest candidates for detached ADUs.

Pasco ADU Market at a Glance

$1,277/mo
Avg 1BR ADU Rent
verified data
+28%
Property Value Uplift
verified data
5.3%
Avg Cap Rate
verified data
97%
Avg Occupancy
verified data

Pasco ADU Zoning Regulations

Regulation Pasco Allowance
Max ADU Size 1,000 sq ft
Max Height 25 ft
Side Setback 0 ft
Rear Setback 0 ft
Owner Occupancy Not required
Short-Term Rental Restricted
Coastal Overlay No
Design Review Yes - in historic districts only
HOA Prevalence 8% of properties

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

Pasco 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 Building Division
3
Plan Review ~1.2 week
Approx. 1.2 weeks — faster with complete drawings
4
Permit Issuance ~0.5 week
Fees: $8,429–$13,905
Building Department
Building Division
(509) 543-5726
Visit Department ↗ Online Permit Portal ↗

Local ADU Lenders in Pasco

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

Gesa Credit Union
HELOC

HELOCs and home equity loans $10,000–$500,000; HELOC floor APR ~3.95% and ceiling 18%; membership required and property must be in WA/OR/ID.

Visit Lender ↗
STCU (Spokane Teachers Credit Union)
Construction loan

One‑step construction loans financing up to ~90% of the home’s value with interest‑only payments during construction; available in Tri‑Cities/Eastern WA.

Visit Lender ↗
RenoFi
Renovation loan

Renovation HELOC/Home Equity products (partner lenders) that can fund up to $750K and use after‑renovation value (ARV) to increase borrowing power — often suitable for ADU conversions.

Visit Lender ↗
Banner Bank
HELOC

Banner offers HELOCs and home equity loans for renovations with promotional fixed introductory options (example: 5.29% fixed first 12 months) and max LTV around 80%.

Visit Lender ↗
1st Security Bank of Washington (1st Security Bank)
HELOC

Offers HELOCs (disclosure shows lending up to ~80% LTV, variable APR floor ~3.99% and max 18%, typical 10‑year draw + repayment periods).

Visit Lender ↗

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

Vetted ADU Contractors in Pasco

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

Hearthwood Construction
All
(360) 852-3670
View Contractor ↗
Remodels Plus Construction LLC
All
(509) 578-8467
View Contractor ↗
KAS Construction
All
(509) 579-9312
View Contractor ↗
Saddle Mountain Homes
Home addition
(509) 331-8101
View Contractor ↗
Hamm-err Down Construction LLC
All
(509) 989-9505
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 Pasco 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 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 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 Pasco ADU Package

Site Plan
Property setbacks, ADU location, utilities — formatted for Pasco 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 WA energy code
🔩
Structural (Premium)
Stamped structural drawings — required for most detached ADUs in CA

Engineered for WA 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 WA Codes
Every drawing set is engineered for California's current building standards: Title 24 energy compliance, CBC, NEC electrical, and local Pasco 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.

Pasco ADU Drawing Costs — Compared

What homeowners typically pay for permit-ready ADU drawings in Pasco, 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 Pasco's building department requirements and WA code. Delivered in 10 business days.

03

Submit to Your City

Download your complete drawing package and submit directly to Building 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 · Pasco
✓ Permitted
Build Cost
$192,000
Monthly Rent
$1,277/mo

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

— Marcus T. Permit: 1.2 weeks
Garage Conversion to ADU
480 sq ft · Franklin County
✓ Permitted
Build Cost
$95,000
Monthly Rent
$930/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 · Pasco
✓ Permitted
Build Cost
$110,250
Monthly Rent
$930/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.

Pasco Climate Zone & Energy Code

Climate Zone
Zone 5B
CA Title 24 zone
Seismic Zone
C
Structural design req.
California Title 24 Energy Compliance

Washington State Energy Code (WSEC) — Based on the 2021 IECC (WAC 51-11R for residential), ADUs must meet specific envelope, mechanical, and lighting provisions effective as of March 15, 2024.

Pasco vs. Nearby Washington Cities

CityBuild Cost/sqftPermit Fees1BR ADU RentCap RateDrawings
Pasco ← you $300 $8,429+ $1,277/mo 5.3% From $997
Seattle $550 $11,638+ $2,015/mo 5.2% View →
Spokane $300 $3,000+ $1,161/mo 6.5% View →
Tacoma $280 $3,000+ $1,496/mo 5.8% View →
Vancouver $250 $14,940+ $1,484/mo 5.4% View →

Pasco ADU Questions

How much does it cost to build an ADU in Pasco? +
Construction costs in Pasco 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 N/A base.
What is the maximum ADU size allowed in Pasco? +
Pasco permits ADUs up to 1,000 sq ft. The maximum height is 25 ft. Side setbacks are 0 ft and rear setbacks are 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 Pasco? +
Plan check in Pasco typically takes 1.2 weeks. Permit fees range from $8,429 to $13,905. Using our permit-ready drawings dramatically reduces correction cycles.
Do I need owner-occupancy to build an ADU in Pasco? +
No — Pasco 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 Pasco? +
In Pasco, a 1-bedroom ADU rents for approximately $1,277/month. Studios average $930 and 2-bedroom units bring $1,628. With an occupancy rate of 97%, annual gross rent on a 1BR ADU would be approximately $14,864.
How much does it cost to get ADU drawings in Pasco? +
Our permit-ready ADU drawing packages for Pasco start at $997 — compared to $3,000–$8,000 for a local architect. Every set is engineered for WA 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 Pasco'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 WA-code compliant and formatted for local submission.
Can I convert my garage to an ADU in Pasco? +
Garage conversions are generally permitted in Pasco under California ADU law. Costs are lower than new construction. Our garage conversion drawing package starts at $997 and covers all plans required for permit submission.
What neighborhoods in Pasco are best for ADU investment? +
West Pasco, Downtown Pasco, Columbia Park / Riverfront area. High single‑family density, larger lots and higher home values with strong buyer/renter interest make this ideal for detached ADUs.
Is Pasco ADU-friendly? +
Pasco 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. Pasco allows ADUs up to 1,000 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 Pasco? +
ADUs in Pasco typically increase property values by 28%. On a $330,000 home, that's an estimated $92,400 in added value. Cap rates average 5.3% in Pasco.
Can I use my Pasco ADU as a short-term rental (Airbnb / VRBO)? +
Pasco 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.
Does Pasco's seismic zone affect ADU construction requirements? +
Pasco falls within Seismic Design Category C. 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 Pasco'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 Pasco? +
Building Division handles ADU permit applications — online submission is available through the permit portal. Permit fees in Pasco range from $8,429 to $13,905 depending on project scope and valuation. Plan check typically takes 1.2 weeks. Our drawing sets are formatted specifically for Pasco's submittal requirements to minimize plan check cycles.

More Services in Pasco

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

Start Your Pasco ADU Today

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

Get My ADU Drawings →

Questions? Your coordinator responds within 4 business hours.