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 & Restoration Contractor in Bellevue, WA | Premium Services

Premium Roofing & Restoration Services for Bellevue Properties

We serve Bellevue and the surrounding upscale residential communities with expert roofing, restoration, and exterior services. We understand that Bellevue homeowners have high standards for quality, craftsmanship, and customer service. We meet and exceed those standards with every project. Whether your Bellevue home needs storm damage restoration, a premium roof replacement, exterior painting that enhances your property’s value, or comprehensive restoration after an insurance claim, our team brings the expertise, attention to detail, and professionalism that Bellevue residents expect.

Bellevue’s varied elevation and architectural styles require contractors who understand both technical excellence and aesthetic considerations. We’ve successfully completed hundreds of projects for Bellevue homeowners who appreciate quality craftsmanship and professional service. We use premium materials, employ skilled craftspeople, and manage projects with meticulous attention to detail. Your home is your most valuable asset, and we treat it accordingly.

Services Available in Bellevue:

  • Premium Roofing: Residential roof replacement with architectural shingles, metal roofing, and premium materials
  • Insurance Restoration: Comprehensive storm damage restoration with insurance coordination
  • Exterior Painting: High-end residential painting for Bellevue homes and properties
  • Siding Services: Premium vinyl siding and fiber cement installation for Bellevue homes
  • Concrete & Hardscape: Decorative driveways, patios, and walkways for Bellevue properties
  • Drywall & Interior Services: Premium finishing and water damage restoration
  • Pressure Washing: Professional cleaning and maintenance of Bellevue properties

Why Bellevue Residents Choose Prolific Design-Build and Restoration

We’re experienced in serving Bellevue’s most discerning homeowners. We understand that quality matters, timelines matter, and customer communication matters. We maintain a professional appearance, manage projects carefully, and deliver results that exceed expectations. We’ve earned the trust of Bellevue residents through consistent delivery of excellent work and outstanding service. Many of our Bellevue clients become long-term partners, calling us for multiple projects and referring us to their neighbors and friends.

Bellevue homeowners: Experience the Prolific Solutions difference. Call or text (425) 800-4775 for your free consultation and estimate. We’re proud to serve Bellevue’s most valued properties. Schedule your consultation online anytime.

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

📋 Get a Free Estimate