What is the cost to connect a new addition to Ottawa's municipal sewer and water?

When an addition includes plumbing fixtures, such as a bathroom, kitchen, laundry or in-law suite, the new space has to connect to your home's water supply and drainage, and through them to the municipal services. The cost depends mainly on whether you can tie into the existing internal plumbing or need new service connections from the street.

Tying into existing plumbing. For most additions, new fixtures connect to the house's existing water supply and drain-waste-vent system. Cost depends on the number of fixtures, the distance to the existing drain stack, and whether the addition sits on a slab, a crawlspace or a basement. A single bathroom next to an existing stack is the simple case. An addition at the far end of the house, or a detached structure, needs longer runs and costs more.

New service lines from the street. If your existing water service or sewer lateral is undersized or in poor condition, which is more likely in older homes, the plumber may recommend replacing it. That involves excavation, possibly work in the road allowance, and restoration, and it can be one of the larger plumbing costs on a project. Ask the City what permits and approvals apply to work on the service connections for your property.

Permits and trades. The City lists plumbing alterations, additions or extensions to a plumbing system (except replacing existing fixtures) as work that needs a building permit, and it is usually handled with the addition's permit. Plumbers are a compulsory trade in Ontario, and you can check a worker's authorization on the Skilled Trades Ontario Public Register. Rough-in work is inspected before walls are closed.

Storm and sanitary connections. Some older areas have combined sewers and others have separate storm and sanitary systems. Your plumber and designer need to confirm what serves your property so the addition connects correctly.

Backwater valves. A backwater valve protects the house from sewer backup. Ask your plumber whether one is required for your project and whether it makes sense to add one while the drains are open.

Fixtures below the sewer. A basement bathroom or laundry that sits below the level of the sewer lateral needs a sewage ejector pump, with an accessible pit and check valves.

Freeze protection. Water lines in crawlspaces, near exterior walls or underground must be protected from freezing. Ask how deep new underground lines will be buried and how interior lines will be insulated.

To compare itemized quotes, browse plumbers and addition contractors in the Ottawa Construction Network directory.

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Looking for experienced contractors? The Ottawa Construction Network connects homeowners with qualified professionals:

• Homeupgraders
• JC Carpentry
• ALM Construction & Landscaping Inc.
• M.O.T. CONSTRUCTION INC.
• Geerts Roofing Inc