Why Seattle's New DADU Rules Matter for Builders & Investors

Seattle's One Seattle Plan is changing how investors, builders, and homeowners can develop property and the new DADU rules may create some of the biggest opportunities Seattle has seen in years. In this HouseHack Seattle session, builder David Weisser breaks down what the latest zoning and DADU changes actually mean, how Seattle is interpreting the new code, and what investors should know before starting their next project. In this video you'll learn: • How the new DADU rules increase development potential • Why taller DADUs and higher lot coverage change project feasibility • The difference between building DADUs and larger multi-unit developments • Hidden costs and risks investors often overlook • How Seattle's interim code could impact your next project Whether you're building your first DADU or evaluating your next investment, this discussion will help you understand where the biggest opportunities and biggest risks are under Seattle's new development rules. Subscribe to HouseHack Seattle for more videos on Seattle real estate investing, DADUs, zoning updates, development strategies, and market insights. --- 0:00 Introduction & The Code Shift 0:31 “Trust But Verify” – Confusing New Code 1:37 How Builders Are Navigating Interpretation 2:50 ADU Changes: What’s New 4:45 Height Increase – Up to 37 ft Total 5:57 Attached DADUs (ADU Duplex Concept) 7:34 Lot Coverage Increase (35% → 50%) 10:13 Garage Limits & Undefined Storage 11:06 No Forced Frontage Improvements 11:52 ADUs vs. Bigger Projects – Risk & Ease 12:47 Going Bigger: 4–6 Unit Development 14:34 Higher Risk Factors (IBC, ADA, Sprinklers) 16:00 Underground Power Requirements (Cost Impact) 20:48 Why This Code Matters for Everyone 22:54 Built Green Requirements (Cost & Admin) 25:41 MHA Fees – The Deal Killer 29:23 Investors Canceling Old Permits 31:05 Designing New 3-Story DADUs 40:48 Rising Construction Costs (+15%) 50:29 High Voltage Setback – 14 ft Rule 54:17 Hold vs. Sell: Finish Levels 56:57 Financing a Hold (DSCR, 40-Yr Loans) 1:01:05 Flipping for W-2 Earners 1:02:06 The Condominiumization Problem 1:14:15 Partial Reconveyance Explained 1:16:05 Conclusion 📍 Filmed in Seattle - with local real estate pros sharing how they’re preparing for the next wave of opportunities. Watch until the end for David’s take on which areas might boom first under the new zoning rules. 💡 Want to learn more? 1. Setup a free, 1-1 Intro call: https://calendly.com/d/d4g-2c3-gg7 2. Join 1,000+ other investors at the largest & most active HouseHacking Meetup in WA State: https://www.meetup.com/house-hack-sea... 3. Find us online at https://househackseattle.com/ 4. Apply for a Hard Money Loan for your next investment here: https://www.certainlending.com/house-... 🤝 Special thanks to our sponsors: 🏦 Kara Rozanski - OriginPoint (Mortgage Lender) Trusted loan expert helping investors close tough deals. Avid multifamily investor herself — her latest duplex came through HouseHack Seattle! 🏗️ David Weisser - Backyard ADU (DADU Builder) Helping investors build DADUs efficiently with tight control on budget, schedule, and quality. 💰Israel Lopez - Certain Lending (Hard Money Lender) Former contractor and flipper turned expert loan officer specializing in new construction & BRRRR projects. 🏘️ Sagareus Property Management Streamlined leasing, maintenance, and inspections for serious investors building long-term wealth. 👉🏻 Follow us on Instagram:   / michaeljohaas     / jess_haas     / househackseattle   #househackseattle #seattlerealestate #realestateinvesting #landbuyingtips #brrrr #househacking #buildingwealth #realestate #seattlehomes #downtownseattle #pnwrealestate #seattlerealtors #2025 #shorts #success #mindset #adu #dadu #oneseattleplan