Home/Modular Homes by City/London
Serving London & southwestern Ontario
Modular Homes & Garden Suites in London, Ontario
Factory-direct modular homes and backyard suites for London. London ties an additional residential unit's size to your own home — here's what's allowed, what it costs, and the by-law that applies.
What you can build in London
Full modular homes — from $175,696. 29 models from 560 to 1,405 sq ft, 1–3 bedrooms — factory-built to the Ontario Building Code and set on a permanent foundation (a real, permanent house, not a “trailer”).
Backyard suites (ADUs) — from $96,244. 7 compact models built for garden-suite and in-law-suite use, sized to fit what London's by-law allows.
All homes are CSA-certified (A277 modular / Z240MH manufactured), finished in the factory, and delivered ready for foundation and hook-up. What's the difference between modular, manufactured, and mobile? →
Find your backyard suite — 3 quick questions
We'll narrow the models that fit a typical London backyard allowance to the ones that fit your life. No email needed.
1 · Who's it for?
2 · What layout?
3 · What size feels right? (London lots typically allow up to ~700 sq ft)
London sizes a detached suite to your home — each unit can be up to 80% of your dwelling’s floor area (no fixed m² cap). Your exact lot may allow more or less — get the real number for your address in seconds.
Check your exact London address →Can you put a garden suite (ADU) in your London backyard?
Often, yes — London permits a detached Additional Residential Unit on most serviced residential lots. The specifics, from City of London Zoning By-law Z.-1 §4.37 (Additional Residential Units), as amended:
| Max size | No fixed m² cap — each unit may be up to 80% of your home’s gross floor area (minimum 17.5 m² / ≈188 sq ft). |
|---|---|
| Max height | 6.0 m (≈20 ft) for a detached unit |
| Setbacks | 3.0 m (≈10 ft) rear; interior side the greater of the zone’s requirement or 1.2 m (≈4 ft). Rear or interior side yard only — never the front. |
| Units per lot | Up to 3 additional units (4 dwellings total); up to 2 may be detached |
| Parking | None required |
| Servicing | Municipal water & sewer — no private septic for a detached unit |
| Conservation | Upper Thames River Conservation Authority (UTRCA); Kettle Creek & Lower Thames Valley CAs on the City’s edges |
Getting your building permit in London
An eligible lot still needs a building permit before anything is delivered. Here's how London's process actually works — verified against the London building department's own pages.
How do you apply for an ADU building permit in London?
Through Building Development Permit (BDP) portal (application portal ↗). Building-permit applications, including detached ARUs, are submitted online through the BDP citizen portal — drawings and forms uploaded, payment made at submission. London's building-permit page ↗
- Review London's ARU rules and confirm zoning compliance with the City's dedicated ARU Coordinator (aru@london.ca) before drawing up plans
- Have a qualified BCIN designer, architect, or engineer prepare the Schedule 1 form, site plan, and architectural drawings
- Assemble the supporting documents — Energy Efficiency Design Summary, HVAC design with heat-loss/gain calculations, engineer-stamped truss package where used
- Submit the complete package with payment through the BDP citizen portal
- Respond to any additional-information requests during review; the permit issues once the review clears
- If the ARU will be rented, apply separately for a Residential Rental Unit Licence after construction and pass the property-standards and fire inspections
What does a London ADU permit application need?
- Schedule 1: Designer Information form
- Site/plot plan to scale showing the detached ARU's location, setbacks, and lot coverage
- Architectural plans (foundation, floor plans, elevations, sections) signed by the designer
- Energy Efficiency Design Summary (EEDS)
- HVAC design form with heat-loss/gain calculations and duct layout
- Engineer-stamped roof-truss package where pre-engineered trusses are used
How much does an ADU building permit cost in London?
London calculates the permit fee from project size and scope rather than one flat ARU rate — Building Services quotes the exact figure at application; the confirmed floor is a $260.37 minimum permit fee, so treat any total as an estimate. If the unit will be rented, budget about $346 for the initial Residential Rental Unit Licence (application + fire inspection) plus $65/year to renew.
| Permit fee | Calculated from project size/scope; minimum $260.37 — Building Services confirms the exact fee at application |
|---|---|
| Rental licence (only if rented) | $175 application + $171 fire inspection, then $65/year renewal |
| ARU Construction Grant (incentive, not a fee) | Up to $20,000 standard / up to $45,000 for affordable or Indigenous-led units — confirm current intake |
A detached ARU added alongside an existing single-detached, semi-detached, or street-townhouse home is exempt from development charges — Building Services confirms eligibility during the permit application.
How long does an ADU building permit take in London?
Ontario's Building Code requires a decision on a complete house-class application within 10 business days. The clock starts only once the Building Division deems the application complete — incomplete submissions or unresolved zoning issues delay the start.
Registration: A Residential Rental Unit Licence is required if the completed ARU will be rented (not if it houses family or stays owner-occupied) — it includes mandatory property-standards and fire inspections.
Worth knowing before you apply
- Interim Control By-law CP-1600-300 caps bedrooms (max 2 per ARU, 5 total across all ARUs on a property) — Council paused higher-density ARU approvals in late 2025 pending a review, so confirm the current status with the ARU Coordinator
- London has a dedicated ARU Coordinator (aru@london.ca, 519-661-2489 x4946) — using them before design saves rework
- A detached ARU must sit in the rear or interior side yard — never the front, and never between the house and the street on a corner lot
- A lot-grading plan may be required to show drainage isn't disrupted
- No additional parking is required — or permitted — for an ARU (no new driveways)
Fees and timelines are estimates from London's published schedules, verified July 4, 2026. Rates and processes change — always confirm current requirements with the building department before you apply.
Grants & financing in London
London ARU Construction Grant — Up to $20,000 toward building a new additional residential unit — up to $45,000 for affordable or Indigenous-led units. Confirm current intake with the City.
See every program → Ontario ADU Grants Directory
A modular or prefab home on a permanent foundation is financed like any house. CMHC Prefab Plus allows an insured mortgage with as little as 5% down on the first $500,000, with construction funds released in stages. How modular home financing works →
Thinking of the suite as a rental? Run the numbers →
London modular homes — FAQ
Can you put an ADU in London, Ontario?
Yes. London permits up to three additional residential units on most residential lots (four dwellings total), with up to two of them detached — subject to size, height, and setback rules and a building permit.
How big can a backyard unit be in London?
London doesn’t set a fixed square-footage cap — instead, each unit can be up to 80% of your home’s gross floor area (minimum 17.5 m² / ≈188 sq ft). A larger house allows a larger suite. Check your address for the specifics.
Can you put a modular home in London?
Yes. On land you own, a modular home on a permanent foundation is legal residential housing under the Ontario Building Code throughout London, subject to standard zoning and permits.
How much does a modular home or backyard suite cost in London?
Modular home models start at $175,696 and run to about $338,000 for the largest layouts; backyard ADU models start at $96,244. Site work, foundation, delivery, and permits are additional.
Can I get a mortgage on a modular home in London?
Yes — on a permanent foundation it is financed as real property, including via CMHC Prefab Plus (5% down on the first $500,000).
Local rules summarized from City of London Zoning By-law Z.-1 §4.37 (Additional Residential Units), as amended; verified by Modular Homes 400 and reviewed by James Clarke, REALTOR®. Always confirm current requirements with the City of London before you build.