Home Addition Drawings · Redmond, WA
Permit-Ready Home Addition
Drawings for Redmond, WA
Expand your home with a permitted room addition, second story, or family room extension. We deliver complete, code-compliant drawing sets for Redmond's building department — in 10 business days, starting at $1,497.
14-day money-back guarantee · 10 business day turnaround
Local Intelligence
What Redmond Homeowners Need to Know Before Submitting
Size & Zoning Rules
Any new square footage added to your Redmond home counts against the same zoning envelope that governs ADU size, meaning large additions may affect your ability to add a future ADU. Redmond's current ADU size cap is 1,000 sq ft — within the typical range for most floor plan configurations.
Redmond currently requires owner-occupancy on the primary parcel — meaning one of the units (the main home or the ADU/conversion) must be your primary residence.
If the addition creates a second unit or is later converted to a rental, Redmond's ADU market supports approximately $2,845/month for a 2-bedroom unit.
Permit Process & Fees
Development Services Center permit fees for this project type typically range from $30,194 to $33,749 depending on project valuation and scope. Plan check runs approximately 8 weeks — though each correction cycle adds 3–6 weeks, which is why code-compliant drawings matter so much.
Addition permit packages submitted to Development Services Center must include a site plan, floor plans, all four elevations, an electrical plan, and energy compliance documentation — plus stamped structural drawings are always required for any load-bearing elements, second-story work, or new foundation.
Visit Development Services Center ↗Construction Cost Context
Redmond's home addition construction costs run $245–$416 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 Redmond
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.
Expert Verdict — Marcus Reid, Licensed Designer
"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."
Market Context
Redmond has a median home value of $1,100,000. Comparable renovation projects in this market typically add 28% to resale value.
Neighborhoods in Redmond with the strongest home addition and resale value potential 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.
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 falls within Seismic Design Category Seismic Design Category D (D2 for residential) per ASCE 7 / IBC, which affects structural requirements for any new addition tying into the existing structure.
Local Financing Resources
Local Home Addition Lenders in Redmond
These lenders offer HELOC, construction, and renovation loans for home addition 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 Home Addition Contractors in Redmond
We draw the plans. These contractors build the addition. 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.
Drawing Package Details
What's Included in Your Redmond Home Addition Package
Transparent Pricing
Redmond Home Addition Drawing Packages
One-time fee. No retainer. No hourly billing.
- ✓Site plan
- ✓Floor plans (existing + proposed)
- ✓All 4 elevations
- ✓Electrical plan
- ✓Title 24 energy compliance
- ✓PDF + DWG delivery
- ✓10 business day turnaround
- ✓Everything in Starter
- ✓Stamped structural drawings
- ✓Foundation plan
- ✓Roof framing plan
- ✓Window & door schedules
- ✓1 round of revisions
- ✓Everything in Standard
- ✓3D rendering
- ✓Cross-section details
- ✓Material specifications
- ✓HOA submission package
- ✓2 rounds of revisions
- ✓Priority 5-day turnaround
After You Order
Your Addition Drawings in 3 Steps
Submit Your Project Details
Share your property address, existing floor plan (if available), and the addition scope. We assign your project coordinator within 4 business hours.
We Draft Your Drawings
Our team designs your complete addition drawing set — engineered for Redmond's building department requirements and WA CBC code. Delivered in 10 business days.
Submit to Your Building Dept
Download your complete package and submit to Development Services Center. We support plan check corrections at no extra charge.
Common Questions
Redmond Home Addition FAQs
Do I need a permit for a home addition in Redmond? +
Yes — any structural addition to your home in Redmond requires a building permit. This applies to room additions, second-story additions, sunrooms, and attached garages. You'll need permit-ready drawings before the building department will accept your application. Our packages are formatted specifically for Redmond's submittal requirements.
How much does a home addition cost in Redmond? +
Home additions in Redmond typically cost between $275.0–$350 per square foot depending on the scope, finishes, and structural complexity. A 600 sq ft addition ranges from $165,000 to $210,000. Second-story additions cost more than ground-floor extensions due to structural requirements. Our drawing packages start at $1,497 — a fraction of local architectural fees.
What drawings are required to permit a home addition in Redmond? +
Redmond's building department requires: a site plan showing the addition's footprint and setbacks, floor plans for all affected levels, all four exterior elevations, an electrical plan, and energy compliance (Title 24 in California). Structural plans stamped by a licensed engineer are required for any load-bearing elements — included in our Premium package.
How long does the permit process take for a home addition in Redmond? +
Plan check in Redmond typically takes 8 weeks for home additions. Additions with structural components may require additional review. Complete, code-compliant drawings significantly reduce correction cycles — each cycle adds 3–6 weeks. Our drawings are engineered to pass on the first submittal.
What setbacks apply to home additions in Redmond? +
Redmond enforces minimum setbacks from property lines for all additions: typically 4–5 ft side setbacks and 5 ft rear setbacks, though these vary by zoning district and lot size. Your addition must stay within the buildable envelope. Our site plan documents existing and proposed setbacks and flags any zoning variances required.
Do I need structural drawings for a home addition in Redmond? +
Yes, for most additions. Any load-bearing walls, new foundations, second-story construction, or roof structure changes require stamped structural drawings from a licensed engineer. California's CBC (California Building Code) and seismic requirements make structural plans mandatory for most addition types. Our Standard and Premium packages include stamped structural drawings.
How much do home addition drawings cost in Redmond? +
Our permit-ready home addition drawing packages for Redmond start at $1,497. Local architects and designers typically charge $3,000–$10,000+ for comparable drawing sets. Every package is engineered for WA code compliance and formatted for Redmond's building department. Turnaround is 10 business days with a 14-day money-back guarantee.
Will a home addition increase my home's value in Redmond? +
In Redmond, where median home values are approximately $1,100,000, a permitted home addition adds square footage that appraisers value as part of the home's gross living area. Return on investment varies by addition type — master suite additions, family room expansions, and additional bedrooms typically recoup 50–75% of project cost in appraised value in WA markets.
Can I add a second story to my home in Redmond? +
Second-story additions are permitted in most Redmond residential zones, subject to height limits and design review requirements. California generally requires ministerial permit approval, but some cities impose design compatibility or neighborhood compatibility review for second stories. Our drawings cover all levels including foundation upgrades, shear walls, and roof framing required for vertical additions.
Also Available in Redmond
Adding an ADU instead? See our ADU design service.
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.