Project Overview
A complete gut-and-rebuild with dual-unit configuration in North London
Property Details
AddressNorth London, Ontario
Lot Size60 × 152 ft
Property TypeDetached — 2-Storey
NeighbourhoodNorth London (near Sherwood Forest)
ProximitySteps to bus, Sherwood Forest Mall; mins to Western / UH
Unit Configuration
Main Unit4 bedrooms, 2.5 bathrooms
Suite Unit1 bedroom, 1 bathroom (basement)
Kitchens2 (one per unit)
Laundry2 × separated laundry
Suite EntranceSeparate side entrance
Legal Status✅ Fully permitted & inspected
Main Unit Finishes
Kitchen CountersQuartz with tile backsplash
IslandBreakfast island, waterfall counter
CabinetsStylish modern cabinets & hardware
AppliancesAll-new stainless steel
2nd FloorOption: 4 beds or 3 beds + WFH office + ensuite
Permits & Inspections
ArchitectArchitectural drawings (issued + re-issued)
EngineerLetter re: triple beam (structural)
City Inspection✅ Final completed
ESA Inspection✅ Completed
Plumbing Inspection✅ Completed
Why Add a Legal Basement Secondary Suite?
A legal secondary suite transforms a single-family home into an income-generating asset — increasing both the property's rental yield and its market value. In London, Ontario, proximity to Western University, University Hospital, and major employment corridors means demand for rental housing is consistently high.
Mortgage Helper Math: A 1-bedroom basement suite renting at $1,500/month in North London offsets approximately $1,500 of your mortgage — effectively reducing your carrying costs by $18,000/year.
The key distinction on this project was doing it properly: with permits, inspections, and full Building Code compliance. This allowed the property to be marketed as a "legal second suite" — commanding a premium and attracting a broader buyer pool (owner-occupants, investors, and buyers who need a mortgage helper).
~$1,500–$1,800
Est. Monthly Rental Income (1-bed basement, North London 2024)
$18,000–$21,600
Annualized Rental Income
Legal Status
Higher resale value vs. unpermitted suite — buyers can finance confidently
Before & After
The property was acquired in original condition and fully gut-renovated. These photos document the before and after across all areas of the home.
⬤ Before Renovation
Basement — Open Joists & Concrete Floor
Basement — Mechanicals & Staircase
Kitchen — Original Condition
Front Entry Foyer
Main Floor Hallway
Dining Room — Original Condition
Bedroom — Original Condition
Bathroom — Original Condition
⬤ After Renovation
Main Floor Living Room — Open Concept
Living Room — Fireplace & Bay Windows
Kitchen — White Cabinets & Island
Kitchen & Dining — Marble Floors
Main Unit — Bedroom
Upper Floor Bedroom
Basement Suite — Living Area & Fireplace
Basement Suite — Full Kitchen
Basement Suite — Bedroom & Egress Window
Basement Suite — Glass Shower Bathroom
Finished Property Gallery
Professional listing photos showing the completed renovation across both units.
Exterior — North London Property
Front Entrance
Kitchen — Quartz Waterfall Island
Main Floor Living/Dining
Master Bedroom
Basement Suite — Living Area
Basement Suite — Kitchen
Basement Suite — Bathroom
Floor Plans
Approved architectural drawings showing all three levels of the renovated property.
Basement — Secondary Suite Floor Plan
Main Floor Plan
Second Floor Plan — 4 Bedrooms / 3+Office
The Renovation Process: Step by Step
From acquisition to final inspections — creating a legal secondary suite requires coordinating permits, architects, engineers, trades, and multiple inspections.
1
Pre-Acquisition
Property Evaluation & Due Diligence
Assessed basement layout, ceiling height, egress window potential, existing plumbing location, and overall structural condition. Ran the numbers on renovation cost vs. ARV (After Renovation Value) with a target 1-bed/1-bath suite.
2
Design Phase
Architectural Drawings & Engineer Review
Engaged a Building Code–registered designer to prepare full architectural drawings: floor plans for all three levels, fire separation details (CDI F1.1), window well specifications, and Basement Finish CDI M5.2. A structural engineer reviewed and signed off on the triple-beam configuration.
3
Permit Application (2023)
City of London Building Permit Submission
Submitted Form 14 application with drawings in August 2023. The city issued a response letter in September 2023. Fees were paid and the permit was issued. Drawings were re-issued to address city comments before construction commenced.
4
Construction
Full Gut Renovation — Main Unit + Basement Suite
Construction proceeded in stages: structural work (triple beams), rough plumbing, rough electrical, HVAC, insulation and vapour barrier, fire separation framing and drywall, egress window well installation, finishing (flooring, tile, cabinetry, painting). Both units were built out simultaneously to reduce timeline.
5
Inspections (2023–2024)
Required Building Inspections
Passed all required inspection stages: framing, insulation/vapour barrier, rough plumbing, fire separation (CDI F1.1 details), HVAC, and final occupancy. ESA (Electrical Safety Authority) inspection was also arranged and passed separately.
6
2024
Final Sign-Off & Listing
Received City of London Final Inspection Completed Notice and Plumbing Inspection Completed Notice. ESA Inspection Outcome Summary confirmed. Property listed on MLS with professional photography emphasizing the legal secondary suite as a key value driver.
Permits & Inspections Summary
| Item | Details | Status |
|---|---|---|
| Architectural Drawings | Construction Plans (ARCH) — issued + re-issued | ✅ Approved |
| Structural Engineer | Triple Beam review and sign-off letter | ✅ Complete |
| Fire Separation | CDI F1.1 Secondary Dwelling Fire Separation Details | ✅ Passed |
| Basement Finish | CDI M5.2 — mechanical/finish specs | ✅ Passed |
| Window Well / Egress | Egress window well drawing and installation | ✅ Passed |
| Plumbing Inspection | City of London rough-in + final plumbing | ✅ Complete |
| ESA Electrical Inspection | Electrical Safety Authority — full electrical | ✅ Complete |
| Final City Inspection | City of London Final Inspection Completed Notice | ✅ Complete |
Why permits matter when selling: A legally permitted secondary suite can be disclosed to mortgage lenders — allowing buyers to use the rental income to qualify for a larger mortgage. An unpermitted suite cannot be included in mortgage qualification, significantly limiting your buyer pool.
Key Features: The Basement Secondary Suite
The basement suite on this project was designed to Ontario Building Code standards for secondary dwelling units, ensuring safety, comfort, and compliance. Key design elements included:
- Separate side entrance — private access, no shared foyer
- 1 bedroom, 1 full bathroom
- Full kitchen with appliances
- Separate laundry
- Egress window wells per OBC requirements
- Fire-rated separation (1-hour assembly, CDI F1.1)
- Sound insulation between units
- Dedicated HVAC servicing
- Bright, above-grade windows for natural light
OBC Requirement Highlights for Basement Secondary Suites:
- Min. ceiling height: 1.95m (6'5") in habitable rooms
- Egress window: min. 0.35 m² openable area
- Fire separation: min. 30-min. assembly between units
- Interconnected smoke alarms
- CO detectors where fuel-burning appliances exist
- Separate entrance or ability to exit without going through other unit
- Must have kitchen, bathroom, and sleeping area
Results & Investment Outcomes
Legal
Fully Permitted Secondary Suite
~$1,500+
Est. Monthly Rental Income (suite)
9
Inspections & Sign-Offs Obtained
2 Units
Legal Dwelling Units Created
60×152
Lot Size — Future Garden Suite Potential
Investor Note: The 60×152 ft lot size also creates potential for a future Accessory Dwelling Unit (ADU / garden suite) at the rear of the property under Ontario's More Homes Built Faster Act, which now permits as-of-right ADU development on most residential lots in Ontario.
7 Lessons from This Project
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Always pull the permit.Unpermitted work creates liability at sale and limits the buyer pool. A legal suite commands a premium — and buyers can include rental income in mortgage qualification only when the unit is permitted.
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Get drawings before buying.Commissioning preliminary architectural drawings before finalizing purchase lets you confirm feasibility (ceiling height, egress, plumbing location) and budget accurately — avoiding surprises post-acquisition.
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Separate entrance adds significant value.A private side entrance for the basement suite eliminates shared space friction, commands higher rent, and is required for full OBC compliance as an independent dwelling unit.
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Budget for permit response time.The City of London issued a response letter in September 2023 requesting changes. Factor 6–12 weeks for permit issuance (longer if revisions are required) into your project timeline and carrying cost budget.
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Fire separation is non-negotiable.The CDI F1.1 fire separation between units and CDI M5.2 basement finish spec must be followed precisely. Fire separation inspections are staged — plan framing and insulation around inspection bookings.
-
Market the legal status prominently.The MLS listing explicitly stated "Legal 1 bed 1 bath second suite" and "all required permits and inspections completed." This differentiated the property from comparable homes with unpermitted suites.
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Consider lot size for future ADU potential.The 60×152 ft lot means a future buyer could add a detached garden suite or laneway house at the rear — adding to the investment thesis and long-term upside of the property.
Frequently Asked Questions
Common questions about basement secondary suites in London, Ontario
How much does it cost to create a legal basement secondary suite in London, Ontario?
Costs vary significantly based on existing condition and scope of work. A full renovation (gut to studs) including plumbing, electrical, egress windows, fire separation, insulation, flooring, kitchen, and bathroom typically ranges from $60,000–$120,000+ in London, ON. Permit fees are typically $1,000–$3,000. A legalization-only project (where the basement is already partially finished but unpermitted) can run $30,000–$60,000.
What permits are required for a basement secondary suite in London, Ontario?
A Building Permit from the City of London Building Division is required. The application must include architectural drawings (floor plans, sections, elevations), fire separation details, egress window well specifications, and a site plan. Separate inspections are also required for electrical (ESA), plumbing, HVAC, and the final occupancy. Zoning confirmation confirming your property allows a secondary dwelling is the first step before submitting drawings.
How long does it take to build a legal basement secondary suite?
From permit application to occupancy, plan 6–12 months. The City of London typically takes 4–10 weeks to issue a building permit (longer if revisions are required). Construction itself runs 3–6 months depending on complexity. Inspections at each stage (framing, insulation, rough plumbing, fire separation, final) add time — book inspections early and plan your construction schedule around them.
How much rental income can a legal basement suite generate in London, Ontario?
A 1-bedroom legal basement suite in North or West London typically rents for $1,400–$1,800/month in 2024–2025. Areas near Western University, University Hospital, or major bus routes command the higher end. A 2-bedroom suite can reach $1,700–$2,200/month. This income can offset $700–$1,000+ of monthly mortgage costs after expenses.
Does London, Ontario allow basement secondary suites in all residential zones?
Under Ontario's More Homes Built Faster Act and subsequent provincial housing legislation, secondary suites and additional residential units (ARUs) are now permitted as-of-right in all residential zones in Ontario, including London. The City of London updated its ARU regulations in May 2025 to reflect these provincial requirements. Always confirm your specific property's zoning and lot coverage with the City's Planning Division before beginning.
What is the difference between a "secondary suite" and an "ADU" or "ARU"?
These terms are often used interchangeably. A secondary suite (or secondary dwelling unit / SDU) is typically an additional unit within an existing house — like a basement apartment. An ADU (Additional Dwelling Unit) or ARU (Additional Residential Unit) is the broader provincial term that includes both internal suites and detached structures (garden suites, laneway houses, coach houses). Under Ontario's More Homes Built Faster Act, up to 3 units are permitted on most residential lots.