ADU & DADU Rough-In Plumbing in Seattle
Call us now for any and all plumbing needs!
Expert Plumbing for building ADUs and DADUs in Seattle
Planning to add an Accessory Dwelling Unit (ADU) or Detached Accessory Dwelling Unit (DADU) to your Seattle property? Knockout Plumbing & Mechanical provides expert rough-in plumbing services to ensure your new build is up to code and ready for finishing work.
We work closely with homeowners, builders, and general contractors during the early construction phase to properly route water supply lines, drain lines, gas lines, and venting systems. Our team ensures your ADU/DADU is fully prepped for future kitchen, bathroom, and laundry installations.
Our Rough-In Plumbing Services Include:
✅ Water supply line layout and installation
✅ Drain-waste-vent (DWV) system installation
✅ Stub-outs for toilets, sinks, tubs, and appliances
✅ Gas line rough-ins for water heaters or cooktops
✅ Code-compliant venting and pipe sizing
✅ Coordination with city inspections and permitting
Why Choose Knockout for ADU & DADU Plumbing?
Over a decade of experience working on residential additions and conversions
Deep knowledge of Seattle plumbing codes and permit requirements
Fast, clean, and precise installations that keep your project on track
Clear communication with general contractors and inspectors
FAQ – ADU & DADU Plumbing
What is rough-in plumbing?
Rough-in plumbing is the phase where all the pipes are laid out within the walls and floors, but no fixtures are connected yet. It’s the foundational stage of any plumbing system.
Do I need permits for plumbing an ADU or DADU?
Yes, permits are always required. Our team pulls all necessary permits and schedules inspections as part of our service.
Can you help with fixture installation too?
Yes! After the rough-in is complete and inspections are passed, we can return to complete the trim-out phase, including installing toilets, faucets, tubs, and more.
Can you install gas lines in an ADU?
We sure can. We’ll install and pressure test gas lines for appliances like tankless water heaters, ranges, and dryers.
Let’s Get Your Project Moving Ready to get started on your ADU or DADU plumbing? Call Knockout Plumbing & Mechanical at (206) 858-2211 or click here to request a quote. Let’s make your build smooth, safe, and code-compliant.
