Bill 23, the More Homes Built Faster Act, 2022, allows most residential lots in Ontario to contain up to three residential units as-of-right — without a zoning amendment or minor variance — and exempts those additional units from municipal development charges, parkland dedication fees and community benefits charges. For a London homeowner, that means a garden suite in the backyard is now a permitted use on most lots, not a rezoning fight.
That is the short version. The details matter, because "as-of-right" does not mean "no rules," and the exemption from development charges does not mean "no fees at all."
What exactly did Bill 23 change?
Bill 23 changed three things that directly affect a single homeowner adding a unit:
- Three units as-of-right. Provincial legislation permits up to three residential units on most urban residential lots serviced by municipal water and sewer — typically a main house plus two additional units, or two units in the main house plus one detached garden suite.
- No development charges on those additional units. Municipalities cannot levy development charges, parkland dedication or community benefits charges on the additional units created under this framework.
- No extra parking required. Municipalities cannot require more than one parking space per unit for these additional residential units, and many have gone further.
The province also removed the ability of municipalities to require a site plan control application for most projects of ten units or fewer, which shortens the approvals path considerably for a single ADU.
Terminology, quickly
- ARU / ADU — Additional Residential Unit / Accessory Dwelling Unit. Same idea: a second (or third) self-contained dwelling on a lot with a house.
- Garden suite / detached ARU — a standalone unit in the backyard, with its own kitchen, bathroom and entrance.
- As-of-right — permitted by the zoning bylaw already, so no rezoning or Committee of Adjustment application is needed if you meet the standards.
If you want the full walkthrough of unit types, financing and design, our complete ADU guide covers it in depth.
Does Bill 23 mean my London garden suite is free of fees?
No — Bill 23 removes development charges on additional residential units, but building permit fees, municipal connection and inspection fees, and utility upgrade costs still apply. Those are separate charges and they are set by the City of London and by the utilities, not by the province.
The City of London has also moved independently to expand its own housing incentives and waive certain fees to hit federal Housing Accelerator Fund targets. Those incentive programs change from budget year to budget year, so confirm the current fee schedule and any active waivers directly with the City of London's Development Services team before you budget. Do not rely on a figure you read in an article from a previous year — including this one.
The cost items that most often surprise homeowners are not permits at all. They are the site-specific connections:
| Cost item | Included in a Kuzyn base price? | |---|---| | Complete ADU structure and construction | Yes | | Interior finishes, fixtures, windows, doors | Yes | | HVAC (ductless heat pump) | Yes | | Appliances (fridge, stove, dishwasher, microwave) | Yes | | Quartz countertops, vinyl plank flooring | Yes | | Planning and building permits | Yes | | Tarion warranty (detached units only) | Yes | | Sewer line connection and hookup | No | | Water line connection and hookup | No | | Electrical service connection or panel upgrade | No | | Excavation and trenching (distance-dependent) | No | | Municipal connection and local permit fees | No |
The reason connections sit outside a fixed price is honest arithmetic: a unit 12 metres from the existing service laterals and one 40 metres away across a mature root system are not the same job. We price those after a site visit.
What has London done on top of Bill 23?
London adopted a broader additional residential unit bylaw that goes further than the provincial minimum, and city reporting shows ARU applications have picked up meaningfully under the relaxed rules. Council has also approved city-wide density measures and is actively debating related standards — including residential parking rules and a bedroom cap that some families say limits larger ARUs.
Because those local standards are still in motion, treat the following as things to verify, not fixed facts:
- Maximum size and height for a detached ARU on your lot
- Setbacks from rear and side lot lines
- Lot coverage and required amenity/soft landscaped area
- Bedroom count limits per property
- Tree protection requirements, which are real and can dictate where a unit sits
- Whether your lot is on full municipal services — the three-unit framework generally applies to serviced urban lots
A quick zoning check against your specific address answers all of these in an afternoon. It is the first thing we do on any London project.
Which ADU configuration makes sense on my lot?
Four configurations are common in London, and the right one depends on your lot, your existing house and what you want the unit to do.
| Configuration | Typical cost | Typical timeline | |---|---|---| | Interior / basement conversion | $75,000 – $150,000 | 2–4 months | | Garage conversion | $80,000 – $160,000 | 2–4 months | | Addition to existing house | $120,000 – $220,000 | 4–6 months | | Detached standalone unit | $148,000 – $350,000+ | 4–8 months |
Detached units carry the highest cost and the longest timeline, but they are also the only configuration that qualifies for Tarion warranty coverage in our lineup, and they leave your existing house untouched.
For detached builds, our pre-designed models have published starting prices:
- The Paul — from $148,000 · 321 sq ft · studio · 1 bathroom
- The Maria — from $168,000 · 409 sq ft · 1 bedroom · 1 bathroom
- The Henry — from $218,000 · 549 sq ft · 2 bedroom · 1 bathroom
Browse all three on our ADU models page. Pre-designed models exist for the same reason the city and the federal government have both published design catalogues: a design that has already been drawn, priced and permitted moves faster than one drawn from scratch.
How long does an ADU take in London, start to finish?
Plan on 4 to 8 months of construction for a detached unit and 2 to 4 months for a basement or garage conversion, plus the permit and design period before construction starts. Permit review timelines vary with city workload, so ask Development Services for the current turnaround when you apply rather than assuming last year's pace.
The realistic sequence looks like this: site visit and zoning check → model selection or custom design → permit drawings and submission → permit issued → excavation and services → build → final inspections → occupancy.
Frequently asked questions
Can every London homeowner build three units under Bill 23?
No. The three-unit framework generally applies to urban residential lots on full municipal water and sewer services, and your lot still has to meet zoning standards for setbacks, height, lot coverage and parking. Lots on private septic, lots in heritage conservation districts and unusually small or irregular lots may not qualify or may need a variance. A zoning review against your address is the only way to know for certain.
Do I still need a building permit for a garden suite?
Yes. Every additional residential unit in London requires a building permit, regardless of Bill 23. As-of-right zoning removes the need for a rezoning or minor variance in most cases — it does not remove Ontario Building Code review, permit fees or inspections. Kuzyn Builds includes planning and building permits in our base model prices.
Are development charges really zero on an ADU?
Additional residential units created under the Bill 23 framework are exempt from municipal development charges, parkland dedication and community benefits charges. Other fees still apply, including building permit fees and utility connection charges. Fee schedules and any temporary municipal waivers change annually, so confirm current amounts with the City of London before finalizing your budget.
Can I finance an ADU?
Yes — common routes include a HELOC, a refinance, a construction draw mortgage, or the federal secondary suite refinancing program that allows homeowners to borrow against improved property value to add a suite. Terms, caps and eligibility for federal programs change, so speak with a mortgage broker or your lender about what is currently available before you commit to a build.
Talk to a builder who has done this before
Kuzyn Builds is a family-owned construction company in London, Ontario with 80+ completed projects and more than a decade of work across the province. We build in London, St. Thomas, Strathroy, Sarnia, Grand Bend and throughout Ontario, and we publish our starting prices because homeowners deserve a number they can plan around.
If you are comparing builders, our buyer's guide to ADU builders in London lays out what to ask. If you want to know what your specific lot allows, book a free consultation or call +1-519-694-4776. We will check your zoning, walk the site and give you a real number — connections included.