ADU & DADU Contractor — King County, WA

Add a Legal Dwelling Unit
to Your King County Property

From permit application to final walkthrough — Prolific handles design-build ADU and DADU projects across Federal Way, Issaquah, Renton, Kent, and greater King County.

$180KAverage ADU Cost (King County)
6–12moTypical Timeline Permit to Move-In
$1,800+Monthly Rental Income Potential
3–5yrAverage ROI Payback Period

What We Build

Every ADU project is custom-designed for your lot, your goals, and King County code.

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Detached ADU (DADU)

A standalone dwelling in your backyard. Most flexible for rental or multigenerational living. Requires setback compliance and separate utility connections.

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Attached ADU

Connected to the primary home via a shared wall. Lower cost than detached, faster permitting. Ideal for in-law suites or long-term rental income.

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Junior ADU (JADU)

Converted from existing interior space — garage, basement, or bonus room. Lowest cost entry point. Limited to 500 sq ft per King County code.

The King County Permitting Process

Prolific handles every step. Most homeowners have never pulled a permit — we've done hundreds.

1

Site & Zoning Review

We verify your parcel's zoning, setbacks, lot coverage, and utility capacity before design starts. Catches 80% of project-killers on day one.

2

Design & Engineering

Architectural plans drawn to King County standards. Structural engineering included where required. Typical design phase: 3–6 weeks.

3

Permit Submission

We submit to King County DPER or the applicable city (Federal Way, Renton, Issaquah, Kent). Electronic submission with full plan set.

4

Review & Corrections

County review typically takes 6–12 weeks. We respond to all correction requests and manage the back-and-forth until permit issuance.

5

Build & Final Inspection

Construction with milestone inspections. Final inspection and certificate of occupancy required before the unit can be rented or occupied.

Cost Ranges for King County ADUs

Rough estimates — every project varies by site, size, and finish level. Free estimate available after a site visit.

ADU TypeSize RangeTypical Cost Range
Junior ADU (JADU)Up to 500 sq ft$60,000 – $120,000
Attached ADU400–800 sq ft$120,000 – $200,000
Detached ADU (DADU)400–1,200 sq ft$160,000 – $320,000

Ready to Add a Unit to Your Property?

Free site consultation. We'll tell you what's possible on your lot before you spend a dollar.

Get Your Free ADU Estimate

Prolific's Differentiator

While We're Restoring Your Home, Let's Make It Better Than Before

Most contractors patch the damage and leave. We use the restoration as a launchpad — pairing insurance coverage with a remodel that upgrades what you had.

Storm + Remodel

Federal Way — Hail Damage + Kitchen Upgrade

Insurance covered the roof and siding. While we had the crew on-site, the homeowners financed a kitchen remodel they'd been putting off for years. One mobilization, two wins.

Water + Addition

Renton — Burst Pipe + Primary Bath Expansion

A burst pipe triggered an insurance claim for the subfloor and drywall. We rebuilt the bathroom larger than it was — same timeline, carrier paid the base, owner paid the delta.

Fire + Rebuild

Issaquah — Garage Fire + ADU Conversion

Garage total loss became a permitted two-car garage with a studio ADU above. Insurance rebuilt what burned. The ADU now generates rental income to offset the mortgage.

Insurance Claim? We Handle Everything.

Your Insurance Company Has Adjusters.
Now You Have Us.

STORM DAMAGE RESPONSEthousands more for homeowners just like you.

Roofing Contractor Renton WA

Prolific Design-Build and Restoration provides professional roofing services throughout Renton and surrounding neighborhoods. From Renton Highlands to the Cascade area, we’ve replaced and repaired roofs across Renton’s diverse residential and commercial landscape. Renton’s lower elevation and proximity to Lake Washington and the Cedar River means roofs face constant moisture, moss, and drainage challenges — we build and repair roofs designed to handle every bit of it.

Roofing Services in Renton, WA

Roof Replacement: Complete tear-off and installation with materials rated for Renton’s wet climate — asphalt architectural shingles, metal roofing, and designer shingles. We assess your decking, flashing, and ventilation before a single shingle goes on.

Storm Damage Repair: Renton experiences regular wind and rain storms off the Cascades. We respond quickly, document damage thoroughly for your insurance carrier, and work with adjusters to get your claim approved and your roof restored.

Roof Repair: Leaks, missing shingles, failed flashing, cracked pipe boots — diagnosed and fixed correctly the first time. We don’t patch problems that need replacing, and we don’t replace what genuinely just needs a repair.

Moss & Algae Removal: Renton’s humidity and shade make moss growth a near-universal problem. We treat, remove, and apply zinc or copper strips to slow regrowth — protecting your shingles from the granule loss that shortens roof life.

Roof Inspections: Pre-purchase, post-storm, or annual maintenance checks. Written reports with photos, prioritized repair lists, and honest opinions on remaining roof life — no upselling.

Why Renton Homeowners Choose Prolific

We’ve worked on roofs from Talbot Hill to Kennydale to the Fairwood area. We know the neighborhood differences — the older homes in downtown Renton with original decking that needs evaluation, the newer construction in South Renton with warranty requirements to keep intact, the hilltop homes in Renton Highlands that take more wind exposure than the valley properties below.

Every Prolific roofing project includes a full written estimate before any work begins, daily job site cleanup, and a walkthrough with you when the job is done. We’re licensed, bonded, and insured in Washington State, and we carry the manufacturer certifications required to issue full material warranties on new roofs.

Our Roofing Process

Step 1 — Free Inspection & Estimate: We come out, get on the roof, and give you an honest assessment with photos. No pressure, no surprise charges.

Step 2 — Material Selection: We walk you through shingle grades, color options, and warranty tiers. Most Renton homeowners choose 30-year architectural shingles — a strong balance of durability and cost for our climate.

Step 3 — Scheduled Installation: We confirm your installation date, order materials, and show up on time. A typical Renton residential replacement takes one to two days.

Step 4 — Final Walkthrough: We do a thorough cleanup (including a magnetic sweep for nails), inspect the finished roof with you, and hand over your warranty documentation.

Frequently Asked Questions — Roofing in Renton

How long does a roof replacement take in Renton?
Most single-family homes in Renton take one to two days for a full replacement, weather permitting. We monitor forecasts and schedule around Renton’s rainy season to minimize exposure during the project.

Will my homeowner’s insurance cover storm roof damage in Renton?
Most Washington homeowner policies cover wind and hail damage. We help document the damage, provide a detailed repair estimate, and communicate with your adjuster directly. Many Renton homeowners pay only their deductible.

How often should I have my Renton roof inspected?
We recommend an inspection every two to three years, or after any significant storm. Renton’s wet winters accelerate flashing failures and moss growth — catching issues early is far cheaper than emergency repairs.

What roofing materials work best in Renton’s climate?
Architectural asphalt shingles are the most common and cost-effective choice. Metal roofing is a premium option that handles Renton’s moisture exceptionally well and can last 40–70 years. We carry both and can show you local examples of each.

Ready to get your Renton roof inspected or replaced? Call us at (425) 800-4775 or request a free estimate online. We typically schedule Renton inspections within 2–3 business days.

Also Serving Nearby Cities

Prolific Design-Build and Restoration provides the same professional service across King County.

View all Roofing Services in King County

Dealing with storm damage? We're here — call now or submit your info and we'll call you within the hour.

We Got Your Request

We respond within 2 business hours — same day for emergencies.

A member of our team will reach out shortly to schedule your free estimate or inspection. Here's what to have ready when we call:

What to Have Ready

  • Photos of the damage or area of concern (phone photos are fine)
  • Your insurance carrier name and claim number (if applicable)
  • Best time and number to reach you
  • A rough idea of when the damage occurred or project timeline
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Prolific Design-Build & Restoration — Federal Way, WA

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