Home/Modular Homes by City/Petawawa
Serving the Town of Petawawa (Renfrew County)
Modular Homes & Garden Suites in Petawawa, Ontario
Factory-direct modular homes and backyard suites for the Town of Petawawa — the Ottawa Valley town at the mouth of the Petawawa River, home to Garrison Petawawa. In 2025 the Town rewrote its additional-residential-unit rules (By-law 1752/25): a detached backyard unit is now permitted alongside a house, semi or townhouse, but how many units you get and how big your lot must be depend on whether you're on town water and sewer, town water with a septic, or a private well and septic. Here's what the by-law allows, what it costs, and the rules that apply.
What you can build in Petawawa
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 Petawawa'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 Petawawa 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? (Petawawa lots typically allow up to ~800 sq ft)
Petawawa sets no fixed m² cap — a detached unit can be up to 80% of your house’s floor area and footprint, one storey, max 5 m tall. On a private well and septic the lot must be at least 0.8 ha (≈2 acres), and waterfront lots on private services are excluded. 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 Petawawa address →Can you put a garden suite (ADU) in your Petawawa backyard?
Often, yes — Petawawa permits a detached Additional Residential Unit on most serviced residential lots. The specifics, from Town of Petawawa Zoning By-law 456/07, §3.32 — Additional Residential Units (added by By-law 1752/25; office consolidation August 22, 2025):
| Max size | No fixed m² cap — the unit can be at most 80% of your house’s gross floor area, and a detached unit’s footprint at most 80% of the house’s footprint (§3.32.1(b)). No basement in a detached unit. |
|---|---|
| How many units | On town water and sewer: up to two additional units, no more than one of them detached. On town water with a private septic, or on a private well and septic: one additional unit (§3.32.2–3.32.4). A garden suite counts as your detached unit. |
| Height & setbacks | One storey, max 5 m (≈16 ft); a unit above a detached garage is allowed if the building is no taller than your house (7.5 m in the Rural zone). Not closer to the street than your house; side and rear yards as your house’s zone requires (R1: 1.2 m side / 7.5 m rear); at least 2 m (≈7 ft) from the house unless fireproof. |
| Parking | 1 extra space per unit — tandem is fine — using the house’s driveway; no new driveway except on a corner lot (§3.32.1(a)). |
| Servicing | Town water + private septic: lot at least 0.4 ha (≈1 acre). Private well + septic: lot at least 0.8 ha (≈2 acres), 0.4–0.8 ha by minor variance, and under 2 ha the unit shares the house’s well and septic. Waterfront lots on private services are excluded (a minor variance can be sought over 0.4 ha). |
| Conservation | No conservation authority — flood rules are in the by-law itself: no building below the Ottawa River floodway (113.0 m), floodproofing to 114.2 m in the flood fringe with a surveyor’s elevation plan, a 30 m (≈98 ft) water setback from the rivers, and a flooding/erosion review in the 50 m Petawawa River / Black Bay buffer. |
Check your specific Petawawa address →
Garden suite, laneway suite, in-law suite, ARU, ADU — different names for the same thing: a small, self-contained home in the backyard. New to the idea? Start with prefab garden suites for Ontario — what one costs in Petawawa, and the models that fit →
Petawawa's by-law is verified in our checker, so you can check if a garden suite is allowed at your Petawawa address in about a minute.
Getting your building permit in Petawawa
An eligible lot still needs a building permit before anything is delivered. Here's how Petawawa's process actually works — verified against the Petawawa building department's own pages.
How do you apply for an ADU building permit in Petawawa?
Through Cloudpermit (online building + sewage-system permit applications) — Town of Petawawa Planning and Development, 1111 Victoria Street, Petawawa ON; 613-687-5536 (application portal ↗). Building and sewage-system permits are applied for online through Cloudpermit; the Town posts a Getting Started guide, an attachments guide and a building site-plan template on its Building Department page. The Town issues its own sewage-system (septic) permits. Petawawa's building-permit page ↗
- Confirm zoning and servicing — a detached additional residential unit is permitted under Zoning By-law 456/07 §3.32 (By-law 1752/25) on a lot with a house, semi or townhouse. How many units and the minimum lot size depend on servicing: town water + sewer (up to 2, one detached), town water + septic (1, lot ≥ 0.4 ha), private well + septic (1, lot ≥ 0.8 ha, not on a waterfront lot).
- If the lot falls short (0.4–0.8 ha on private services, a waterfront lot over 0.4 ha, or no house built yet), apply for a minor variance first ($1,625, 2026 Planning Fees).
- On the Ottawa River, check the lot against the FDRP floodplain on the zoning maps — no building below 113.0 m, and flood-fringe buildings floodproofed to 114.2 m with an OLS/P.Eng. survey of that elevation submitted with the permit (§3.25). In the 50 m Petawawa River / Black Bay buffer the Chief Building Official must be satisfied on flooding and erosion first (§3.29).
- On a septic lot, have a qualified designer confirm the system can carry the added unit — under 2 ha the unit must share the house's well and septic — and apply for a Sewage System Permit if it needs a new or upgraded system.
- Retain a BCIN-qualified designer for Ontario Building Code drawings and apply through Cloudpermit with the drawings, site plan and (where needed) septic documents.
- Book inspections through construction, then register the unit with the Town (Second Dwelling Unit Registration, $177 in 2026).
What does a Petawawa ADU permit application need?
- Building permit application with Schedule 1 designer information (BCIN)
- Site plan showing lot lines, all buildings, setbacks to lot lines and the house, the high-water mark and floodline where applicable, the well and septic, driveway and the added parking space
- Construction drawings — foundation, floor plans, elevations, sections, and the residential mechanical-ventilation design summary
- On a septic lot: Schedule 2 sewage-system design and installer form for a new or upgraded system
- On a flood-fringe lot: an Ontario Land Surveyor or P.Eng. plan showing the 114.2 m floodproofing elevation
- Letter of authorization if an agent applies for the owner
How much does an ADU building permit cost in Petawawa?
From the Town's 2026 Permit Fees and 2026 Planning Fees schedules. A new dwelling is $16.00/m² of floor area — an ~74 m² (800 sq ft) detached unit is roughly $1,190 — with a $100 minimum on any permit. A sewage-system permit is $517 and the Second Dwelling Unit Registration $177. If you need a minor variance (a short lot, a waterfront lot, or building the unit before the house) it's $1,625. Additional residential units are exempt from development charges under By-law 1675/24 §3.5–3.6. All figures are estimates — confirm with Planning and Development (613-687-5536).
| Building permit (single-family dwelling rate) | $16.00/m² of floor area (≈$1,190 for ~74 m² / 800 sq ft); $100 minimum |
|---|---|
| Sewage System Permit (septic lots) | $517 |
| Second Dwelling Unit Registration | $177 |
| Minor variance (only if needed) | $1,625 |
| Development charges | EXEMPT for an additional residential unit (By-law 1675/24 §3.5–3.6) — versus $5,236 (rural) to $10,858 (fully serviced) for a new single-detached house, 2024 rates indexed annually |
Petawawa's Development Charges By-law 1675/24 exempts additional residential units in the categories the provincial Development Charges Act sets out (§3.5–3.6) — a second or third unit in or ancillary to a house, semi or rowhouse. A new single-detached house pays $5,236 in rural areas and $10,858 on full services (Schedule A, 2024 rates, indexed annually).
How long does an ADU building permit take in Petawawa?
Ontario's Building Code requires a decision on a complete house-class application within 10 business days. A house-class permit is reviewed within the legislated 10 business days once the application is complete. A minor variance (short lot, waterfront lot, or unit-before-house) adds a minor-variance decision before the permit, and flood-fringe lots need the surveyed elevation plan in hand before you apply.
Registration: Every additional residential unit must be registered with the Town under its Registration By-law (Zoning By-law §3.32.1(c)(viii)) — the Second Dwelling Unit Registration fee is $177 (2026 Permit Fees).
Worth knowing before you apply
- Servicing sets the ceiling: two additional units only on town water AND sewer; one on a septic, with a 0.4 ha (town water) or 0.8 ha (private well) minimum lot
- Waterfront lots on a private well and septic are excluded — a minor variance is the only route, and only on a lot over 0.4 ha
- Along the Ottawa River the floodplain is in the zoning by-law: nothing below 113.0 m, floodproofing to 114.2 m, and a surveyor's elevation plan with the permit
- The house has to be built first — a unit before the house needs a minor variance and a development agreement
- Registration with the Town is required for every unit ($177)
Fees and timelines are estimates from Petawawa's published schedules, verified September 23, 2026. Rates and processes change — always confirm current requirements with the building department before you apply.
Grants & financing in Petawawa
Development-charge exemption for additional units — Petawawa’s development charges on a new single-detached house run $5,236 (rural) to $10,858 (fully serviced) under By-law 1675/24 (2024 rates, indexed annually), but the by-law exempts additional residential units exactly as the provincial Development Charges Act does (§3.5–3.6).
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 →
Petawawa modular homes — FAQ
Can you build a garden suite / ADU in Petawawa?
Yes — Petawawa’s Zoning By-law (§3.32, added by By-law 1752/25) permits a detached additional residential unit on a lot with a single-detached, semi-detached or townhouse dwelling. On town water and sewer you can have up to two additional units (one detached); on a septic or a private well, one. Every unit needs a building permit through Cloudpermit and must be registered with the Town ($177 in 2026).
How big can a garden suite be in Petawawa?
There’s no fixed m² cap — the unit can be at most 80% of your house’s gross floor area, and a detached unit’s footprint at most 80% of the house’s footprint. It’s one storey and max 5 m tall, with the same side and rear yards as your house. Enter your address for the specifics.
Can you build an ADU on well and septic in Petawawa?
Yes, on a large enough lot. On a private well and septic the lot must be at least 0.8 hectares (≈2 acres) — between 0.4 and 0.8 ha only by minor variance — and on a lot under 2 ha the unit must share the house’s existing well and septic. Waterfront lots on private services are excluded unless a minor variance is granted (lots over 0.4 ha). On town water with a private septic the minimum is 0.4 ha.
Can you put a modular home in Petawawa, Ontario?
Yes. On land you own, a CSA A277 modular home on a permanent foundation is legal residential housing under the Ontario Building Code — as the main house or as a detached additional residential unit. A mobile home or RV doesn’t count as an additional unit under the by-law.
How much does a modular home or backyard suite cost in Petawawa?
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 Petawawa?
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 Petawawa Zoning By-law 456/07, §3.32 — Additional Residential Units (added by By-law 1752/25; office consolidation August 22, 2025); verified by Modular Homes 400 and reviewed by James Clarke, REALTOR®. Always confirm current requirements with the municipality before you build.