Ottawa’s page covers both a new-construction requirement and inspection guidance. Read the exact wording for your project: a rule stated for new dwelling units should not be treated as a universal design prescription for every existing house.
What the City says about a permit
The City has a dedicated backwater valve permit page. It says all new single, semi-detached, row house and townhome dwelling units require sanitary backwater valves on sanitary service laterals. That is a requirement for the named new dwelling units; it does not by itself determine the appropriate configuration or scope for every existing-home retrofit.
For a proposed project, use the City's current page and ask the City or a qualified plumbing professional how the applicable permit requirements map to your work. The general information here is not a permit decision or a project-specific plumbing design.
City of Ottawa · current application and project-specific requirements
Plan documents and application details
The City lists a complete set of detailed, legible plans drawn to a conventional scale and the applicable fee among its requirements. Ask what must be shown for your project, who is responsible for preparing and submitting the plan set, and which fee applies at the time of application.
Before submitting
- Which application and supporting documents apply?
- What plan details and scale does the City require?
- What fee is current, and how is the permit issued?
- Who will keep approved plans and specifications available?
Requirements can vary with project circumstances and may be updated. Check the City’s own application instructions rather than using this list as a complete checklist.
Make inspection access part of the schedule
Ottawa's inspection guidance says a normally open valve installed on a sanitary building drain must be within the dwelling unit and accessible for inspection and maintenance. The City also says permit plans and specifications should be available for inspection.
This guidance is specific to the City's stated condition. Do not extend it into a universal placement instruction for all valve types, configurations or existing homes. Confirm what applies to the permitted scope and ensure the work area and documents are available when inspection is arranged. Avoid closing or restoring access before the required review.
Inspection questions should be resolved against the actual permit, plans and project—not a generic web guide.
An orderly permit-to-completion path
Read the City pageMatch the proposed work to current instructions.
Prepare plans & feeConfirm completeness, legibility, scale and applicable fee.
Wait for permit directionResolve questions before starting work.
Coordinate inspectionKeep access and plans available as required.
Retain recordsSave permit, inspection report and invoice.
Permits and rebates are connected, but distinct
The City's protective plumbing rebate program requires supporting permit and inspection records and has its own eligibility and application timeline. A permit is not a rebate approval. Review the separate rebate guide and confirm its current checklist directly with the City.
For the broader work sequence, see the Ottawa installation guide. For anything unclear about an application, inspection or existing-home scope, seek confirmation from the City or a qualified plumbing professional.
Bring the right questions to the assessment.
Use the homepage planning tools to organize what you know; those tools run in your browser. The separate assessment form attempts to email your inquiry to listerplumbing@hotmail.com only after you consent and submit. An inquiry is not a confirmed appointment.