In short
- Riverside South's first homes went up in 1996; the 2021 census counted 19,802 residents (Wikipedia).
- Every Riverside South house from 1996 to 2011 meets the age line for the City's sanitary valve rebate of up to $1,000.
- Manotick is about 25 km from downtown Ottawa and part of the City since 2001; septic work there goes through the Ottawa Septic System Office.
- HomeStars' Ottawa guide prices an egress window at $3,500–$6,000 per window.
Typical prices in Ottawa
| Job | Typical range | Notes |
|---|---|---|
| Egress window for a basement bedroom | $3,500–$6,000 | Per window; Ottawa-wide HomeStars figure |
| Basement bedroom addition, with egress window | $15,000–$30,000 | Ottawa-wide HomeStars figure |
| Waterproofing and insulation before finishing | $5,000–$15,000 | Ottawa-wide HomeStars range |
| City rebate, indoor sanitary backwater valve | up to $1,000 | Built before January 1, 2012 |
| City rebate, sump pump with battery backup in a new pit | up to $3,000 | $1,500 in an existing pit |
Sources. Seen 29.10.2026: HomeStars, Basement Renovation Cost for Ottawa: 2026 Guide (updated 21/08/2026); City of Ottawa, Residential Protective Plumbing program; City of Ottawa, Finishing a basement; Ottawa Septic System Office; Tarion, Warranty coverage after you close. Area facts: Wikipedia, Riverside South, Ottawa and Manotick, read 29.10.2026.
Two different places in one request
Riverside South is a suburb. Manotick is a village on the Rideau River with rural land around it. Both sit in the south end of the City of Ottawa, so the same permit rules and fee schedule apply, but the houses, the services and the drive differ. Say which one you are in, and the year of the house.
Riverside South grew from farmland. The first homes were built in 1996, and the 2021 census counted 19,802 people, according to Wikipedia. It lies southwest of the airport, with building concentrated around River Road, Earl Armstrong Road and west of Limebank Road. Manotick was founded in 1864 by Moss Kent Dickinson around his mill on the Rideau River. It had 5,315 residents in 2021, sits about 25 km from downtown, and became part of the City of Ottawa in 2001.
Builder-finished houses from 1996 onward
Riverside South houses are at most thirty years old. A typical request there is the basement: a bedroom, a bathroom, a home office or a rec room in a space the builder left bare. HomeStars’ Ottawa guide prices a home office at $10,000 to $25,000 and a bedroom addition at $15,000 to $30,000. It puts an egress window at $3,500 to $6,000 per window, because of frost depth and foundation work. Before any finishing, waterproofing and insulation can run another $5,000 to $15,000.
Newer houses may still be under builder warranty. Tarion gives one year for workmanship and Building Code violations, two years for water penetration through basement or foundation walls and for plumbing, electrical and heating distribution, and seven years for major structural defects. Photograph the basement walls and floor before the company starts, and ask what in its scope touches those items. See basement finishing and basement bedroom and egress for the job itself.
Valves and sump pumps while the floor is open
The City’s Residential Protective Plumbing program rebates the lesser of the maximum or the actual cost. Riverside South’s first houses date from 1996, which sorts the area into two groups. Builds from 1996 to 2003 qualify by age for both the sanitary and the storm valve; builds from 2004 to 2011 for the sanitary valve only. Each indoor valve is capped at $1,000. A battery-backed sump pump earns up to $1,500 in an existing pit and $3,000 in a new one, and the plumbing permit fee comes back in full. The permit must be in hand first, and a device that replaces an old one earns nothing.
Finishing more than 10 m² of basement also calls for a City building permit.
Manotick, rural lots and septic
If your Manotick or rural property is on septic, a new bathroom, bedroom or finished basement raises a question that a city lot never asks: can the system carry the load. Septic approvals for the City of Ottawa are handled by the Ottawa Septic System Office, run by the Mississippi Valley and Rideau Valley Conservation Authorities under Part 8 of the Ontario Building Code. The office checks designs, issues permits and inspects, and its site lists system renovations among the approvals. Ask the company on the first call whether it will contact the office, and who pays the application.
The drive
Manotick lies immediately south of Barrhaven and Riverside South, about 25 km from downtown, so the address matters more here than on a downtown lot. Say if your street is narrow or shares a driveway. Line 2 of the O-Train has run to Limebank Road since January 6, 2025.
Where to go next
For bands and cost drivers, see basement finishing cost. Nearby area pages are Barrhaven and Gloucester. Permits: renovation permits in Ottawa.
Who handles a south-end request
The Desk forwards it to one independent renovation company. That company calls, drives out to see the house, and quotes in its own name. Price, dates and any septic paperwork are settled between you and the company.
Questions to ask the company
- My house was built in [year] by a builder. Will your work touch anything the builder's warranty still covers?
- Does my property have a septic system, and will you check with the septic office before you add a bedroom or bathroom?
- Is the basement ready for finishing, or does it need waterproofing and a drain tile check first?
- Can you add a backwater valve or a sump pump while the floor is open, and help with the City rebate paperwork?
Have this ready for the call
- Full address or postal code (K1V and K4M cover Riverside South)
- Year the house was built and the builder's name, if you have it
- For Manotick or rural properties: whether the house is on septic, and the date of the last pump-out
- Possession date for newer homes, in case builder warranty is still running
Questions people ask
How long does Tarion cover a newer Riverside South house?
Tarion’s warranty starts on possession: one year for workmanship, two years for plumbing, electrical, heating and water entering through basement walls, seven years for major structural defects. Damage caused by work the owner adds is a separate matter. Before cutting into walls, ask the company what in its scope touches those items, and photograph the basement first.
Is a newer Riverside South house too new for the valve rebates?
It depends on the year. Builds from 1996 to 2003 clear both age lines, builds from 2004 to 2011 clear only the 2012 line for the sanitary valve, and houses from 2012 on clear neither. Pull the permit before the floor is cut. For permits issued from July 1, 2026, the City gives 18 months to finish the work and file the claim.
Who handles septic approvals for a Manotick house?
The Ottawa Septic System Office, run for the City of Ottawa by the Mississippi Valley and Rideau Valley Conservation Authorities under Part 8 of the Building Code. It lists system renovations among its approvals. If a new bathroom or bedroom is planned on a septic lot, tell the company early so the approval runs alongside the City building permit.
