TL;DR: Quick Summary
- Moving a sink or dishwasher requires rerouting water supply, drain lines, and venting
- Floor joists, slab foundations, and structural layout all affect feasibility
- It’s almost never a true DIY job—hire a licensed plumber
- Factor in permits, inspections, and extra cost for cutting, patching, and code compliance
- When done right, moving fixtures can greatly improve kitchen layout and function
Why You Might Want to Move Plumbing Fixtures
Sometimes, a better kitchen layout requires more than just new cabinets and countertops. Relocating your sink or dishwasher can:
- Improve workflow and create a better work triangle
- Make space for a more open-concept kitchen
- Add functionality to an island or peninsula
- Free up valuable wall space for storage or windows
But unlike cabinets, you can’t just “move” plumbing on a whim—there’s a whole infrastructure hiding behind your drywall (and beneath your floor).
What’s Involved in Moving a Kitchen Sink or Dishwasher?
💧 1. Water Supply Lines
- Hot and cold water must be extended to the new location
- Often run through walls or floors (joists or slabs)
- May require PEX piping reroutes and shut-off valve relocation
- If you’re adding an island sink, you’ll need to run water through the floor
🚽 2. Drainage and Venting
- The drain must slope properly (¼ inch per foot is standard)
- Island sinks need a special venting solution like an air admittance valve or a loop vent
- Improper slope = poor drainage, gurgling, or backflow
- The existing drain location may not allow for sufficient fall without major changes
🧱 3. Structural Limitations
- Are you on a slab? Moving plumbing is much harder (and costlier)
- Are there joists in the way? You can’t notch them too deeply for pipes
- Walls may be load-bearing—so rerouting inside them may require extra support or engineering approval
🧰 4. Permits and Code Compliance
- Plumbing changes almost always require permits and inspections
- Failure to follow code can void insurance or cause failed inspections when selling
- A licensed plumber ensures your system is up to local and national standards
Cost Considerations
| Task | Estimated Cost (CAD) |
|---|---|
| Move sink 3–6 feet | $800–$1,800 |
| Move dishwasher + water line | $500–$1,000 |
| Add venting for island sink | $300–$1,000 |
| Slab cutting for pipe trenching | $1,500–$3,500+ |
| Permit and inspection fees | $200–$500 |
💸 Pro Tip: Even a “small move” can come with big costs if joists or concrete are involved.
Real-World Example
Project: Island Sink Addition in a Vancouver Home
Homeowners wanted to add a sink to their new island. Their kitchen was above a finished basement with limited access.
The plumber had to open the ceiling below, install a loop vent, reroute both hot/cold lines, and slope the new drain across two joist bays.
Final plumbing cost? $3,800—but the final layout looked fantastic and passed inspection with flying colors.
Common Mistakes to Avoid
🚫 Ignoring proper slope – leads to slow drainage or pipe backups
🚫 Assuming it’s DIY-able – no, it’s not just “a couple elbows and some glue”
🚫 Failing to vent properly – island sinks especially need proper air intake
🚫 Using undersized pipes – dishwasher drain lines need ¾” or 1½” depending on your local code
🚫 Skipping permits – don’t risk fines or do-overs
FAQs
Q: Can I run dishwasher and sink drains together?
A: Yes—but it must be done properly, often using a tee and air gap to prevent backflow. Many codes require the dishwasher to connect after the sink trap.
Q: Is it easier in a reno or new build?
A: New builds are easier—everything is exposed. In renos, you’re working around finished floors, ceilings, and cabinetry.
Q: Can I vent an island sink without going through the roof?
A: Yes—air admittance valves (AAVs) are often code-compliant and easier to install, but check your local regulations.
Expert Tip 💡
Plumber’s Pick: “If you’re putting a sink in the island, plan for a garbage disposal and a soap dispenser. You’re already opening up the floor—add convenience while you’re down there.”
Conclusion
Moving a sink or dishwasher can transform your kitchen, but it’s not as simple as dragging a cabinet across the floor. With pipes, vents, slopes, and code compliance all in play, it’s a job best left to experienced pros. Done right, though, it’s one of the best ways to improve both flow and form.
Thinking about a kitchen reconfiguration? We’ll help you move more than cabinets—we’ll make sure your plumbing keeps up, too.
