Home/Modular Homes by City/Mono
Serving the Town of Mono (Dufferin County)
Modular Homes & Garden Suites in Mono, Ontario
Factory-direct modular homes and secondary dwellings for the Town of Mono — the headwaters town north of Orangeville, from Mono Centre and Mono Mills to the rural lines east and west of Hurontario Street. Mono flips the usual ADU rules: a detached secondary dwelling is as-of-right ONLY in the Rural (A) Zone on a lot of at least 10 hectares (≈24.7 acres), and the by-law sets a 74 m² (≈797 sq ft) MINIMUM size rather than a maximum. On every other lot, the as-of-right option is an accessory apartment inside the house. Here's what Zoning Bylaw 78-1 allows, what it costs, and the rules that apply.
What you can build in Mono
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, though note Mono’s unusual rule: a detached secondary dwelling must be at least 74 m² (≈797 sq ft), so these compact suites sit below the legal minimum here — the honest fit for a Mono backyard unit is a small modular home.
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 Mono 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? (Mono lots typically allow up to ~1,200 sq ft)
Mono sets a MINIMUM of 74 m² (≈797 sq ft) for a detached secondary dwelling and no fixed maximum — the unit just has to stay subordinate in size to your main house. That means the compact backyard-suite models are too SMALL to be legal here, and the fit is a small home instead. It's only as-of-right on a Rural (A) lot of 10 ha (≈24.7 acres) or more — enter your address for the specifics. Your exact lot may allow more or less — get the real number for your address in seconds.
Check your exact Mono address →Can you put a garden suite (ADU) in your Mono backyard?
In Mono it depends on the lot: a detached secondary dwelling is as-of-right only on Rural (A) lots of 10 ha (≈24.7 acres) or more, while every home in the Rural and Residential zones can add an accessory apartment inside the house. The specifics, from Town of Mono Comprehensive Zoning Bylaw 78-1, §5(1)(h)–(i) — Accessory Apartments & Secondary Dwelling Units (office consolidation to April 21, 2021):
| Where it’s allowed | A detached secondary dwelling is as-of-right ONLY in the Rural (A) Zone on a lot of at least 10 ha (≈24.7 acres) (§5(1)(i), §20(2)(a)(ii)). On a smaller lot, or in any other zone, a detached unit needs a zoning amendment application to the Town — reviewed as a “moderate” planning file. |
|---|---|
| Size — a minimum, not a maximum | At least 74 m² (≈797 sq ft) — the opposite of most municipalities, so no compact cabins — with no fixed ceiling: the unit must simply stay subordinate in size to your main house. It must also sit within 50 m (≈164 ft) of the house and take no new driveway of its own (§5(1)(i)). |
| The everywhere option | Every home in the Rural and Residential zones can add ONE accessory apartment inside the house instead: up to 30% of the house’s floor area excluding basement and garage — or unlimited size if it’s wholly in the basement — and it must be registered with the Town (§5(1)(h)). |
| Accessory envelope & height | All accessory buildings together may cover up to 140 m² (≈1,507 sq ft) of the lot, Rural-zone accessory floor area runs to 600 m² (≈6,460 sq ft) on lots over 2 ha (site plan control applies over 370 m²), and a detached accessory building can stand up to 12 m (≈39 ft) tall (§5(1)(c), as amended by By-law 2020-47). |
| Parking | 1 space per dwelling unit — and the secondary dwelling cannot have a driveway of its own. |
| Servicing | Mono is well-and-septic country, and the by-law REQUIRES the detached unit to have its own separate septic system (§5(1)(i)(vii)) — the opposite of most municipalities, which make you share the house’s. Budget for a second system, approved before the building permit. |
| Conservation & overlays | Location matters more than usual here. Western Mono is in the Niagara Escarpment Development Control Area, where an NEC Development Permit — not just the Town’s by-law — governs new buildings; eastern Mono carries Oak Ridges Moraine zoning with aquifer-vulnerability and landform overlays. Conservation permits come from the Nottawasaga Valley Conservation Authority for most of Mono, or Credit Valley Conservation in the southwest. |
Getting your building permit in Mono
An eligible lot still needs a building permit before anything is delivered. Here's how Mono's process actually works — verified against the Mono building department's own pages.
How do you apply for an ADU building permit in Mono?
Through CityView Portal (Dufferin County Building Services) + Town of Mono Municipal Approval (application portal ↗). Mono doesn't run its own building department — building AND septic permits are issued by Dufferin County Building Services (519-941-2816 ext. 2700, building@dufferincounty.ca), with applications online-only through the County's CityView Portal. The Town of Mono's own zoning review (the $200 'Municipal Approval') is uploaded into the same CityView application; Town planning questions go to planning@townofmono.com (519-941-3599 ext. 224). Mono's building-permit page ↗
- Confirm zoning first — a detached secondary dwelling is as-of-right only in the Rural (A) Zone on a lot of at least 10 ha (≈24.7 acres), minimum 74 m² (≈797 sq ft), with its own separate septic (Zoning Bylaw 78-1 §5(1)(i)); an accessory apartment inside the house (§5(1)(h)) is the option everywhere else. On a smaller lot, a detached unit means a planning application — the Town reviews a secondary-dwelling file as a 'moderate' planning review ($1,250, Fees & Charges Bylaw 2025-41).
- Check overlays before you design — western Mono is in the Niagara Escarpment Development Control Area, where an NEC Development Permit (applied for through the NEC's own online portal; the NEC lists no charge to apply) must be issued BEFORE the building permit. Elsewhere, NVCA or CVC approval or exemption comes first where the lot is in a regulated area.
- Design the septic — the by-law requires the detached unit to have its OWN separate sewage system, and Dufferin County issues septic permits ($575 for a new residential system, 2026): the septic design, tank and bed layout and clearances go in with the building application.
- Confirm the entrance — the unit can't take a new driveway of its own; where entrance work is needed, the Town's Entrance Permit is $400 plus a $2,500 deposit (Public Works, publicworks@townofmono.com).
- Retain a qualified BCIN designer for the Ontario Building Code drawings — architectural, mechanical (heat-loss and duct design) and the SB-12 Energy Efficient Design Summary, with a Schedule 1 for each designer.
- Register for a CityView Portal account and submit everything in one application: the County's ARU checklist documents, the Town's Municipal Approval application, the site plan (with the septic location) and any entrance-permit application. Incomplete applications are not reviewed — deficiencies come back by email.
- Dual review runs from there — the Town checks Official Plan and Zoning Bylaw conformity while the County checks Building Code compliance — and the permit issues through the Portal. Keep printed approved drawings onsite through inspections.
What does a Mono ADU permit application need?
- Application for a Permit to Construct or Demolish + Schedule 1 Designer Information (one per designer — BCIN, or the homeowner exemption)
- Town of Mono Municipal Approval application, uploaded into the same CityView application
- Site plan drawn to scale — north arrow, address, property lines with distances, dimensions and heights of all structures, entrance/driveway, and all utilities including the septic location
- Architectural drawings: foundation, floor and roof plans, elevations, and cross-sections
- Mechanical drawings by a qualified designer, including heat-loss and duct design
- Energy Efficient Design Summary (SB-12)
- Septic design and calculations (tank and bed layout with clearances) + Schedule 1 (septic designer) and Schedule 2 (septic installer)
- Entrance / Road Occupancy Permit application where entrance work is needed, and the NEC or conservation-authority approval (or exemption) where the lot is regulated
How much does an ADU building permit cost in Mono?
Building-permit fees follow Dufferin County's Building By-law 2020-14, Schedule A (consolidated September 2024; CPI-indexed): an Additional Residential Unit is $16.47/m² in 2026 with a $600 minimum — so a minimum-size 74 m² (≈797 sq ft) detached unit works out to roughly $1,220 — plus the Town's $200 Municipal Approval and a $575 County septic permit for the required separate system. All figures are estimates — confirm with County Building Services (519-941-2816 ext. 2700).
| Building permit — Additional Residential Unit | $16.47/m² (2026), $600 minimum — Dufferin County Building By-law 2020-14, Schedule A; ≈ $1,220 on a minimum-size 74 m² unit (the 2027 rate is $17.83/m²) |
|---|---|
| Town of Mono Municipal Approval | $200 — Fees & Charges Bylaw 2025-41 (an older County process sheet still shows $80; the 2025 by-law governs) |
| Septic (sewage-system) permit — separate system required | $575 (2026) for a new residential on-site sewage system, issued by Dufferin County Building Services — the zoning by-law requires the detached unit to have its own system |
| Entrance Permit — where entrance work is needed | $400 plus a $2,500 deposit (Town Bylaw 2025-41, Schedule D) — note the unit itself cannot have a new driveway of its own |
| Planning path on smaller lots | Secondary-dwelling file reviewed as a Moderate Planning Review, $1,250; a full Zoning Amendment application is $6,000 plus an $11,000 deposit (Bylaw 2025-41, Schedule B) |
| Development charges | EXEMPT for a qualifying unit — up to two additional dwelling units in an existing single detached dwelling or a structure ancillary to it, with floor area no greater than the existing dwelling's (Town DC By-law 2019-42; County DC By-law 2022-28 has the matching exemption) |
Both the Town of Mono (DC By-law 2019-42, as amended) and Dufferin County (DC By-law 2022-28) exempt up to two additional dwelling units in an existing single detached dwelling or a structure ancillary to it, provided the new unit's floor area doesn't exceed the existing dwelling's. Confirm your project's treatment when the permit is issued.
How long does an ADU building permit take in Mono?
Ontario's Building Code requires a decision on a complete house-class application within 10 business days. The County's FAQ says a complete application should issue within the 10 business days — but the Town publishes no turnaround for its Municipal Approval, and where the NEC or a conservation authority regulates the lot, that approval must be issued before the building permit and adds time. Sequence those first.
Registration: An accessory apartment (the in-house unit) must be registered with the Town of Mono under Zoning Bylaw 78-1 §5(1)(h)(v), but no registration form or fee is published — confirm the process with planning@townofmono.com. No separate registration is published for the detached secondary dwelling.
Worth knowing before you apply
- Two governments, one application: the Town of Mono reviews zoning (the $200 Municipal Approval) while Dufferin County reviews the Building Code and issues the permit — all inside the County's CityView Portal, online only, and incomplete applications are not reviewed.
- Western Mono is in the Niagara Escarpment Development Control Area: the NEC Development Permit (no charge to apply, per the NEC) must be issued before the building permit, and the Town's planning pages direct ARU-permission questions there. Check the NEC's online plan map before you design.
- The detached unit's septic must be its own SEPARATE system (§5(1)(i)(vii)) — a $575 County sewage-system permit with a full septic design goes in alongside the building application.
- Any structure over 10 m² (≈108 sq ft) needs a building permit in Dufferin — and a smaller one still does if it has plumbing.
- The stale-$80 trap: the County's Mono process sheet still lists the Town's Municipal Approval at $80; the Town's Fees & Charges Bylaw 2025-41 (which repealed the old fee by-law) sets it at $200.
Fees and timelines are estimates from Mono's published schedules, verified August 27, 2026. Rates and processes change — always confirm current requirements with the building department before you apply.
Grants & financing in Mono
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 →
Mono modular homes — FAQ
Can you build a garden suite / ADU in Mono?
Two different rules apply. A detached secondary dwelling — a separate unit in your yard — is as-of-right only in the Rural (A) Zone on a lot of at least 10 ha (≈24.7 acres), under §5(1)(i) of Zoning Bylaw 78-1. Every home in the Rural and Residential zones can instead add one accessory apartment inside the house, up to 30% of its floor area, registered with the Town (§5(1)(h)). On a smaller lot, a detached unit takes a zoning amendment application.
How big can a detached secondary dwelling be in Mono?
Mono sets a MINIMUM, not a maximum: the unit must be at least 74 m² (≈797 sq ft) — so a compact studio-sized suite is too small to qualify — and its only ceiling is that it stays subordinate in size to your main house. It must sit within 50 m of the house, share the existing driveway, and fit the accessory-building envelope (up to 140 m² of lot coverage across all accessory buildings, height to 12 m). Enter your address for the specifics.
Can you build an ADU on well and septic in Mono?
Yes — in fact it’s essentially the only way, since Mono has no full municipal water-and-sewer service to speak of. That also means Ontario’s Bill 23 as-of-right override — which applies only to fully serviced lots — doesn’t reach Mono, so the by-law’s own gates govern. And note the unusual part: the by-law requires the detached unit to have its OWN separate septic system (§5(1)(i)(vii)), not a connection to the house’s.
Does the Niagara Escarpment affect building in Mono?
On the west side, yes — a large part of western Mono lies in the Niagara Escarpment Development Control Area, where new buildings need a Development Permit from the Niagara Escarpment Commission rather than being governed by the Town’s zoning alone. Eastern Mono carries Oak Ridges Moraine zoning with its own aquifer and landform-conservation overlays. Check which regime your property falls under before you design.
Can you put a modular home in Mono, Ontario?
Yes. On land you own, a CSA A277 modular home on a permanent foundation is legal residential housing under the Ontario Building Code throughout Mono — as the principal dwelling, or as the detached secondary dwelling on a qualifying Rural (A) lot. With Mono’s 74 m² minimum, the fit is a small modular home rather than a compact backyard suite.
How much does a modular home or backyard suite cost in Mono?
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 Mono?
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 Town of Mono Comprehensive Zoning Bylaw 78-1, §5(1)(h)–(i) — Accessory Apartments & Secondary Dwelling Units (office consolidation to April 21, 2021); verified by Modular Homes 400 and reviewed by James Clarke, REALTOR®. Always confirm current requirements with the municipality before you build.