ADU Design Resource · Redmond, WA
The Complete Guide to
Building an ADU in Redmond, WA
Everything Redmond 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.
Created by Build With A Plan · Drawings from $997 (more below)
Quick Answers About Redmond, WA ADUs
Market Context
Redmond has a median home value of $1,100,000. Adding an ADU typically increases that by 28% — approximately $308,000 in added equity. A 1-bedroom ADU in Redmond rents for approximately $2,274/month in the King County rental market , yielding a 3.7% cap rate on the investment. Occupancy averages 92% in this market.
Top Redmond neighborhoods for ADU investment include Overlake, North Redmond, Idylwood, Education Hill, Grass Lawn. Strong rental/job demand from Microsoft and other tech employers plus single-family pockets with lots suitable for detached ADUs. Large-lot single-family neighborhood with high home values and space for detached ADUs.
Permit Process
Permit applications are reviewed by the Development Services Center , with a plan check timeline of approximately 8 weeks. Permit fees in Redmond range from $30,194 to $33,749 depending on project scope. Design review: Other: Generally No; ADUs are processed through standard building-permit (administrative) procedures and are not subject to citywide discretionary design review, but design review (Landmark/Certificate of Appropriateness or higher-level Type II/III review) can be required for properties that are designated historic landmarks or when the project triggers a land-use entitlement.
Redmond's Development Services Center will kick back your ADU plans if your structural engineer hasn't specifically calibrated for Seismic Design Category D2 — many stamped plans from out-of-area engineers use lower seismic assumptions and get bounced in first review, costing you another 3-4 week cycle. Also, if your lot sits in one of Redmond's older neighborhoods like Grasslawn or Idylwood with narrow side sewer lines, expect Public Works to require a sewer capacity check before they'll sign off, since many of these lines were sized decades ago for single-family flow only. Because Redmond allows short-term rentals, you'll also want to confirm your specific parcel isn't in a zone with additional STR business license conditions layered on top of the ADU permit itself.
"In my experience reviewing Redmond ADU submittals, that $350/sqft figure reads more like a state-level average than a true local number — I'd call the Development Services Center or get two or three local contractor quotes before you budget off it. The 8-week timeline is achievable, but only with a clean, complete drawing set; I've seen plenty stretch longer once corrections come back."
11 years in California residential permitting and ADU documentation. This guide was researched and verified against Redmond's building department records and current 2026 California ADU law.
Property Eligibility
Is My Redmond, WA Property Eligible for an ADU?
Redmond 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 Redmond under California state law. Redmond requires owner occupancy — the property owner must reside in the primary home or the ADU. 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 30% of Redmond 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
Other: Generally No; ADUs are processed through standard building-permit (administrative) procedures and are not subject to citywide discretionary design review, but design review (Landmark/Certificate of Appropriateness or higher-level Type II/III review) can be required for properties that are designated historic landmarks or when the project triggers a land-use entitlement.
Always verify eligibility with Development Services Center before designing.
Free Tool · No Email Required
Redmond ADU Return Calculator — Built With 2026 Local Data
Pre-loaded with verified Redmond construction costs, median rental rates, and property value uplift data. Adjust the inputs to model your specific project.
Your Project
Projected Returns
* 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 × 28% uplift (California 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: Development Services Center (source ↗), Zillow Rental Market Reports, California Statewide Communities Development Authority. Last verified: 2026-07-13.
Local Market Data
Top Redmond Neighborhoods for ADU Investment
Overlake
Strong rental/job demand from Microsoft and other tech employers plus single-family pockets with lots suitable for detached ADUs.
North Redmond
Large-lot single-family neighborhood with high home values and space for detached ADUs.
Idylwood
Established single-family area with lake access and lot sizes that support detached ADUs.
Education Hill
Family-oriented neighborhood with larger lots and proximity to schools and parks that support long-term rentals.
Grass Lawn
Predominantly single-family neighborhood near parks and downtown—good lot coverage and ADU opportunity.
Southeast (SE) Redmond
Residential area with a mix of SF homes and access to transit and services, supporting rental demand.
Downtown Redmond
High rental demand for workers and students and walkable location, though smaller lots may favor attached ADUs.
Willows / Rose Hill
Close to jobs and transit corridors with pockets of single-family lots that can support detached ADUs.
Sammamish Valley
More rural/large-lot parcels that make detached ADUs easier to site and attractive for tenants seeking space.
Bear Creek
Lower median values and residential character with single-family lots that can offer lower-cost ADU construction opportunities.
Redmond ADU Market at a Glance
Local Zoning Rules
Redmond ADU Zoning Regulations
| Regulation | Redmond Allowance |
|---|---|
| Max ADU Size | 1,000 sq ft |
| Max Height | 25 ft |
| Side Setback | 5 ft |
| Rear Setback | 5 ft |
| Owner Occupancy | Required |
| Short-Term Rental | Permitted |
| Coastal Overlay | No |
| Design Review | Other: Generally No; ADUs are processed through standard building-permit (administrative) procedures and are not subject to citywide discretionary design review, but design review (Landmark/Certificate of Appropriateness or higher-level Type II/III review) can be required for properties that are designated historic landmarks or when the project triggers a land-use entitlement. |
| HOA Prevalence | 30% of properties |
Data verified Mon Jul 13 2026 00:00:00 GMT+0000 (Coordinated Universal Time). Always confirm with the Development Services Center before designing.
Redmond Permit Process
Redmond ADU Permit Timeline & Fees
ℹ Timeline and fee estimates are based on California state averages. Actual Redmond data coming soon.
Local Financing Resources
Local ADU Lenders in Redmond
These lenders offer HELOC, construction, and renovation loans for ADU projects in King County. Compare terms before committing.
Offers HELOCs with interest-only payments during a typical 10-year draw period; has branch presence in Redmond (serves King County).
Visit Lender ↗Custom Fit home equity/HELOC product for renovations; APRs vary by creditworthiness (example site lists 3.24%–18.00% range).
Visit Lender ↗Offers single-close construction-to-permanent and construction financing options used for owner-occupied projects; LTV and terms vary by product.
Visit Lender ↗Provides construction and construction-to-permanent loans through local mortgage advisors (has loan officers serving Redmond area).
Visit Lender ↗RenoFi is a fintech that partners with credit unions to deliver ADU/renovation loans (platform used by credit unions nationwide, including in Washington).
Visit Lender ↗Build With A Plan is not affiliated with these lenders. Always compare rates and consult a mortgage professional.
Local Build Partners
Vetted ADU Contractors in Redmond
We draw the plans. These contractors build them. Independent — no referral fees paid or received.
Build With A Plan provides drawings only. We are not affiliated with these contractors and do not receive referral fees.
Next Steps
Ready to Move Forward With Your Redmond 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 Development Services Center.
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.
Build With A Plan
$997 – $2,997
- ✓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 Development Services Center. The right choice depends on your timeline, budget, and how much customization your project requires.
Drawing Package Details
What's Included in Your Redmond ADU Package
Engineered for WA Permit Approvals
Transparent Pricing
Redmond ADU Drawing Costs — Compared
What homeowners typically pay for permit-ready ADU drawings in Redmond, by service type:
| Service Type | Price Range | Turnaround | Customization |
|---|---|---|---|
| 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 | $2,497 | 5 days | Enhanced |
- ✓Site plan
- ✓Floor plans
- ✓All 4 elevations
- ✓Electrical plan
- ✓Title 24 energy form
- ✓PDF + DWG delivery
- ✓10 business day turnaround
- ✓Everything in Starter
- ✓Structural plans (stamped)
- ✓Cross-section details
- ✓Window & door schedules
- ✓Material specifications
- ✓1 round of revisions
- ✓Everything in Standard
- ✓3D rendering
- ✓Garage conversion alt plan
- ✓HOA submission package
- ✓2 rounds of revisions
- ✓Priority 5-day turnaround
The Done-For-You Path
Want Your Redmond 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.
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. $6,000 flat — about what an architect charges just to start. Yours would rent around $2,274/mo.
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.
We won't even take your money unless your property qualifies.
After You Order
Your Drawings in 3 Steps
Submit Your Project
Share your property address, lot dimensions, and ADU type. We'll confirm your order and assign your project coordinator.
We Draft Your Drawings
Our team designs your permit-ready drawing set — engineered for Redmond's building department requirements and WA code. Delivered in 10 business days.
Submit to Your City
Download your complete drawing package and submit directly to Development Services Center. We support corrections at no extra charge.
Real Projects · Verified Outcomes
ADU Projects Completed with Build With A Plan
Three representative project scenarios based on actual drawing packages delivered in California cities with similar market conditions to Redmond.
Build costs reflect local construction data for Redmond. Client names are initials only. Permit timelines are project-specific and may vary.
"We'd been quoted $6,200 by a local firm. Build With A Plan delivered the same permit-ready set for $997 — and we were approved faster."
"Conversion permit came back approved on the first review. The drawings handled every detail — egress, HVAC, electrical. Nothing was missing."
"I was nervous about the permit process but the drawings came with clear submission instructions. Approved without a single correction cycle."
Representative scenarios. Build costs modeled using Redmond construction data (city-verified data) and Development Services Center. Outcomes vary by project scope and site conditions.
Building Code
Redmond Climate Zone & Energy Code
WA State Energy Code (WSEC): The Washington State Energy Code, based on the 2021 IECC with Washington amendments, applies to residential buildings (including ADUs) and establishes mandatory envelope, mechanical, and efficiency requirements for new construction and alterations.
Compare Cities
Redmond vs. Nearby Washington Cities
Frequently Asked
Redmond ADU Questions
How much does it cost to build an ADU in Redmond? +
What is the maximum ADU size allowed in Redmond? +
How long does the ADU permit process take in Redmond? +
Do I need owner-occupancy to build an ADU in Redmond? +
What's the rental income potential for an ADU in Redmond? +
How much does it cost to get ADU drawings in Redmond? +
What drawings are included in the permit set? +
Can I convert my garage to an ADU in Redmond? +
What neighborhoods in Redmond are best for ADU investment? +
Is Redmond ADU-friendly? +
How much will an ADU increase my property value in Redmond? +
Can I use my Redmond ADU as a short-term rental (Airbnb / VRBO)? +
Does Redmond's seismic zone affect ADU construction requirements? +
Where do I submit ADU plans in Redmond? +
More Services in Redmond
Free · No Obligation
Not Sure If Your Redmond Lot Qualifies?
Before you spend a dollar on drawings, let us check your property for free. We'll tell you honestly whether your Redmond lot supports an ADU, what it could rent for, and what to do next — no pressure, no sales pitch.
Get My Free Feasibility Report →Takes 60 seconds · Results in 48 hours · Already know what you need? See pricing ↑