Permit-Ready Garage Conversion
Drawings for St. Helens, OR

Convert your garage into permitted living space or a rental unit. We deliver complete, code-compliant drawing sets ready for St. Helens's building department — 14-day money-back guarantee.
Check If My Garage Qualifies → Conversion FAQ ↓

14-day money-back guarantee · 10 business day turnaround

Conversion Cost Range
$35,000 – $77,000
St. Helens estimate
Drawing Package
Permit-Ready Set
contact us for pricing
Turnaround
10 Business Days
vs 4–8 weeks locally
Conversion Allowed
Yes
OR state law applies

What St. Helens Homeowners Need to Know Before Submitting

Size & Zoning Rules

Converting your garage to a legal rental unit means the finished space must comply with St. Helens's ADU size limits. St. Helens's current ADU size cap is 900 sq ft — within the typical range for most floor plan configurations.

St. Helens does not impose an owner-occupancy requirement, so you can rent both the main home and any ADU or conversion as investment units.

A fully permitted, code-compliant garage conversion in St. Helens can command approximately $1,325/month as a 1-bedroom rental — far more than leaving the space as storage.

Permit Process & Fees

Columbia County Building Division permit fees for this project type typically range from $5,000 to $15,000 depending on project valuation and scope.

Garage conversion drawings submitted to Columbia County Building Division must include a site plan, floor plans, all four elevations, an electrical plan, and energy compliance documentation — plus stamped structural plans are typically required for converted garages that are detached or require seismic upgrades.

Visit Columbia County Building Division ↗

Construction Cost Context

St. Helens's garage conversion construction costs run $150–$300 per square foot — a wide range driven by labor markets, local code complexity, and finish level. Our drawings are priced at a fraction of what a full-service architect would charge to produce the same permit set.

⚠ Common Pitfall in St. Helens

Here's a quirk that trips up a lot of homeowners: even though St. Helens sits inside Columbia County, the county building division doesn't actually handle permits for the city itself — St. Helens uses its own contract plan reviewer, so calling the county office for status updates or fee questions just wastes time and gets you bounced back to the city. Because the whole area sits in Seismic Zone D, your foundation and shear wall details get extra scrutiny during plan check, which often means a second round of engineering revisions if your designer used a generic ADU plan set not calibrated for local seismic requirements. Also, many older St. Helens lots still run on shared or undersized sewer laterals from the early 1900s platting, so the city may require a sewer scope inspection before signing off on your ADU's utility connection — a step that can add real delays if the line needs replacing.

Expert Verdict — Marcus Reid, Licensed Designer

"In my experience with Columbia County submittals, both that blank permit timeline and the missing per-square-foot cost are really just placeholders rather than St. Helens-specific numbers, so I'd call the Columbia County Building Division and get a couple of local contractor bids before penciling in a budget or schedule. I've also seen STR-friendly ADUs here draw more HOA scrutiny than that 14% figure suggests, so don't assume your lot is in the clear just because coastal overlay doesn't apply."

Market Context

St. Helens has a median home value of $400,000. Comparable renovation projects in this market typically add 25% to resale value.

Neighborhoods in St. Helens with the strongest garage conversion and rental-unit potential include West St. Helens, Plymouth, Historic Downtown, Riverfront District, Houlton. Highest cash-on-cash potential — Highway 30 corridor pulls Portland commuters and hospital staff, and older, smaller SFH stock on practical lots rents readily as ADUs.

Permit Process

Permit applications are reviewed by the Columbia County Building Division. Permit fees in St. Helens range from $5,000 to $15,000 depending on project scope. Design review: Yes - in historic districts only.

St. Helens falls within Seismic Design Category D, which affects structural requirements for converted garage walls and foundations.

Local Garage Conversion Lenders in St. Helens

These lenders offer HELOC, construction, and renovation loans for garage conversion projects in Columbia County. Compare terms before committing.

InRoads Credit Union
HELOC

Local St. Helens branch offering home equity lines of credit with APRs from 6.500% to 10.000%.

Visit Lender ↗
Oregon State Credit Union
Construction loan

Statewide credit union offering home construction loans with 15-, 20-, or 30-year terms and as little as 20% down for new builds and renovations.

Visit Lender ↗
RenoFi
Construction loan

Specialty ADU lender qualifying borrowers based on future home value post-construction; operates in Oregon with the Plus One ADU Program.

Visit Lender ↗
Wauna Credit Union
HELOC

Local credit union with a St. Helens branch offering HELOCs as low as 6.75% and fixed-rate home equity loans with 10–20 year terms.

Visit Lender ↗
Columbia Credit Union
HELOC

Local not-for-profit serving the region with lump-sum home equity loans and revolving lines of credit for home projects.

Visit Lender ↗

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

Vetted Garage Conversion Contractors in St. Helens

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

Jenson General Contracting
All
(503) 310-6844
View Contractor ↗
ClarkBuilt
All★ 5 (34)
View Contractor ↗
Harbold Homes LLC
All★ 5 (4)
View Contractor ↗

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

Can Your St. Helens Garage Legally Become Living Space?

Not every garage qualifies. Send us the address and we’ll check ceiling height, setbacks, parking-replacement rules, and what St. Helens will actually permit — before you spend anything.

  • Whether your garage meets St. Helens conversion rules
  • Parking-replacement requirements that catch most owners out
  • Ceiling height, egress, and fire-separation checks
  • What the finished space could rent for
  • A straight answer within 48 hours

Check My Garage — Free

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

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

What's Included in Your St. Helens Garage Conversion Package

Site Plan
Existing garage footprint, setbacks, and lot layout formatted for St. Helens submittal
📐
Floor Plans
Converted interior layout with new walls, entry door, egress window, and room dimensions
🏠
Elevations (4 sides)
Exterior views showing new door, window, and infilled garage door opening
Electrical Plan
Outlet, switch, lighting, and panel layout per NEC and applicable OR electrical code amendments
☀️
Energy Compliance
OR energy code compliance — required for all habitable conversions in OR
🔩
Structural (Premium)
Stamped structural drawings for detached garages or where seismic upgrades are required

What's in Your St. Helens Garage Conversion Package

One-time fee, no retainer, no hourly billing — your exact scope and price confirmed on a free call.

Starter
The core permit set. Priced on your free call.
  • Site plan
  • Floor plans
  • All 4 elevations
  • Electrical plan
  • OR 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
  • HOA submission package
  • ADU conversion alt plan
  • 2 rounds of revisions
  • Priority 5-day turnaround
Check My Eligibility →

Your Conversion Drawings in 3 Steps

01

Submit Your Garage Details

Share your property address, garage dimensions, and intended use (ADU, rental, home office). We confirm your order and assign your project coordinator within 4 business hours.

02

We Draft Your Drawings

Our team designs your complete conversion drawing set — engineered for St. Helens's building department requirements and OR code. Delivered in 10 business days.

03

Submit to Your Building Dept

Download your complete package and submit to Columbia County Building Division. We support plan check corrections at no extra charge.

St. Helens Garage Conversion FAQs

Is a garage conversion allowed in St. Helens? +

Yes — garage conversions are permitted in St. Helens. Oregon state law allow homeowners to convert an attached or detached garage into habitable living space or an ADU. A building permit and permit-ready drawings are required before work begins.

How much does a garage conversion cost in St. Helens? +

Garage conversions in St. Helens typically range from $35,000 to $77,000 depending on the existing structure, finish level, and scope of work. This is significantly less than building a new detached ADU. Contact us to discuss drawing package options for your project.

What drawings are required to permit a garage conversion in St. Helens? +

St. Helens's building department requires: a site plan showing the converted garage's location on the lot, floor plans with dimensions and room labels, all four exterior elevations, an electrical plan, and energy compliance documentation (the Oregon Residential Energy Efficiency Specialty Code). Our Starter package covers all of these. If the garage is detached or the structure requires seismic upgrades, stamped structural drawings are also required — included in our Premium package.

How long does the permit process take for a garage conversion in St. Helens? +

Plan check in St. Helens typically takes approximately 6 weeks. Having complete, code-compliant drawings dramatically reduces correction cycles — which each add 3–6 weeks. Our drawings are designed to pass on the first submittal.

Can I convert my garage into a rental unit in St. Helens? +

Yes — a permitted garage conversion can function as a standalone rental unit (an ADU, or a similar accessory-unit category depending on Oregon's and St. Helens's local rules). It can be rented long-term. Short-term rental rules vary by city — confirm with St. Helens's planning department.

Do I need to replace the garage door opening when converting? +

Yes. The garage door must be replaced with an insulated wall with a standard entry door and at least one egress window (minimum 5.7 sq ft clear opening). This is captured in our elevation drawings and flagged in the electrical plan. The new wall must also meet OR energy code requirements, which we handle in the OR energy code compliance documentation.

How much does it cost to get garage conversion drawings in St. Helens? +

Our permit-ready garage conversion drawing packages for St. Helens include floor plans, elevations, electrical, and energy compliance — everything your building department needs. Every package is engineered for OR code compliance and formatted for St. Helens's building department. 14-day money-back guarantee.

Will converting my garage increase my home's value in St. Helens? +

A permitted garage conversion in St. Helens adds rentable square footage to a home currently valued around $400,000. Converted spaces typically appraise as habitable square footage, increasing the home's value. As an ADU or JADU, the rental income stream is also capitalized into the appraised value — typically at a 5–6% cap rate.

Nearby Cities

Portland Salem Eugene Gresham

From the Blog

8 Garage Conversion Ideas Worth the Permit (With 2026 Costs) Read the article → Garage Conversion Permit: Cost, Timeline, and How to Get One Approved Read the article →

Also Available in St. Helens

Need full ADU design drawings instead?

View ADU Design →

Ready to Move Forward With Your St. Helens 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 Columbia County 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

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 Columbia County Building Division. 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 →