Renovation Plumbing: What to Plan Before a Bathroom or Kitchen Reno

The plumbing is the part of a bathroom or kitchen renovation that homeowners think about least and that affects the budget most. Decisions made before the demo, like whether to move a fixture or open a wall, set the cost and the timeline for the whole job. Get the plumbing planned early and the renovation runs smoothly. Leave it as an afterthought and it becomes the thing that holds everything up. Here is what to sort out first.

Are you moving fixtures or keeping them in place?

This is the single biggest plumbing decision in any renovation. Keeping the sink, toilet, tub, and shower roughly where they are keeps the work and the cost down, because the existing drains and supply lines stay put. Moving fixtures to a new layout means relocating drains and supply, which is more involved, especially when a drain has to be rerouted under a floor. Neither is wrong. The point is to decide early, because the layout drives everything else.

Understand the stages of renovation plumbing

Plumbing in a renovation happens in two main visits, not one:

• Rough in. With walls and floors open, the plumber sets the drains, vents, and supply lines for the new layout. This happens before insulation and drywall, and it has to be right because it gets covered up.
• Finishing. Once tiling and cabinetry are done, the plumber sets and connects the fixtures, the faucets, toilet, sink, tub, and shower trim.

Knowing this rhythm helps you coordinate trades so the plumber is on site at the right moments and the project does not stall waiting on one stage. This staged approach is the core of how we handle renovation plumbing.

It is the right time to fix old problems

When the walls are already open, it costs far less to deal with things you would otherwise pay to access later. Aging supply pipes, weak water pressure, or a drain that has always been slow are all easier to address mid renovation. If low pressure has bothered you, a reno is the natural time to trace and fix it, as our blog on low water pressure explains.

Permits and code

Plumbing work in a renovation generally has to meet the Ontario plumbing code, and moving or adding fixtures often requires a permit and inspection. (Confirm permit requirements for your specific scope with your municipality.) This protects you, because code compliant work passes inspection and does not come back to haunt a future sale. Building the permit and inspection time into the schedule from the start avoids a surprise delay later.

Plan for the budget honestly

Plumbing cost in a renovation comes down to how much you move and what condition the existing system is in. A like for like update is modest. A full layout change with relocated drains is more. Rather than a guess, the right approach is to look at your plans and your existing plumbing, then give you a clear price before the work starts, so the plumbing is a known number rather than a mid project surprise.

Frequently asked questions

Do I need a permit for renovation plumbing in Ontario?

Often yes, especially when you move or add fixtures. The work generally has to meet the Ontario plumbing code and may need a permit and inspection. Confirm the requirements for your scope with your municipality before starting.

Is it cheaper to keep fixtures in the same place?

Usually, yes. Keeping the sink, toilet, and tub where they are reuses the existing drains and supply lines, which keeps the plumbing work and cost down. Moving them means relocating those lines, which adds to both.

When does the plumber come during a renovation?

In two stages. The rough in happens while walls and floors are open, before drywall. The finishing happens after tiling and cabinetry, when fixtures are set and connected. Coordinating both keeps the project moving.

Should I update old pipes during a renovation?

It is often the smart time. With walls already open, addressing aging pipes or weak water pressure costs far less than accessing them later. It is worth asking your plumber what is worth doing while everything is exposed.

How much does renovation plumbing cost?

It depends on how much you move and the condition of the existing system. A like for like update is modest, while a full layout change costs more. The reliable way to know is to have your plans and plumbing assessed for a clear price up front.

Planning a bathroom or kitchen renovation? MBM Plumbing handles the rough in and finishing, coordinates with your other trades, and gives you a clear price before the work begins. Serving Markham and the surrounding area.

Request a quote