Accessory Dwelling Units in Portland: Plumbing for Your ADU

What Is An Accessory Dwelling Unit?

An accessory dwelling unit is an independent residence on the same property or lot as the main residence. 

ADU’s are also known as in-law units, granny flats, or additional dwelling units.

They’re often used for:

Why Is Proper Plumbing for Accessory Dwelling Units Important?

Just like any residence, accessory dwelling units need proper plumbing for the bathroom, kitchen, and laundry area (if that’s included in the floor plan).

Without standard plumbing, you wouldn’t be able to use the space as a rental or any other type of housing long-term.

Accessory Dwelling Unit Plumbing: How We Can Help

Whatever your project might entail, we’re confident we can help you with all your ADU plumbing needs.

If you don’t see what you’re looking for from the information below, you can give us a call at 503-750-8323 with any plumbing-related inquiries.

Water Line Connection

Most accessory dwelling unit plans include using the same water line from the main living unit and running it out to the ADU.

However, this isn’t always possible. It depends on the accessibility of your main water pipes and whether or not there’s a place to run pipes out to the ADU.

But don’t worry. 

We can assess your specific setup and figure out the easiest way to run water to your accessory dwelling unit.

Sewer or Septic Tank Service

If you have a sewer system, we can connect the lines to your ADU to ensure proper flow and drainage.

A septic tank might be a little more tricky. If your tank is small, it might not be able to handle another bathroom connected to it. 

But we’ve got you covered. 

We can come up with the best way to get the correct plumbing to your unit.

ADU Plumbing Maintenance

Already have your plumbing installed and running in your accessory dwelling unit?

We offer maintenance and repair for all your plumbing needs.

ADU Plumbing Cost: What to Expect

The cost to provide plumbing to your accessory dwelling unit depends on the amount of work and materials needed to get the job done.

Looking for a quote for your ADU plumbing? 

We’d be happy to go over your specific plumbing project and offer an estimate.


We pride ourselves in being quick and thorough. We understand that it's not ideal having a plumber in your home - that's why it's our commitment to get the job done as quickly as possible.