Prefab Cottages in Oshawa: What's Allowed on Your Lot and What It Costs
Last updated: August 7, 2026
Prefab cottages in Oshawa start at $229,500 for a compact plan, quoted separately from your property costs.
The bigger variable is not which model you choose — it’s which legal path you build under.
✓ HCRA Licensed | ✓ Tarion Enrolled | ✓ CSA A277 | ✓ Ontario-Built
A new dwelling on its own lot currently attracts $130,682 in municipal, education and parkland charges. The same building placed behind an existing house, as an additional dwelling unit, is exempt from $116,947 of that under the Development Charges Act — leaving roughly $13,700 in school board charges and parkland cash-in-lieu that may still apply.
That one distinction moves an Oshawa budget more than any design decision.
Below: the cottage plans available, what they cost, what Zoning By-law 60-94 actually permits in an Oshawa backyard, and the approvals sequence — using the City of Oshawa’s own published rates as of July 1, 2026.
My Own Cottage is an HCRA-licensed, Tarion-enrolled builder based in Orillia, working throughout Durham Region. This is the Oshawa page in our prefab cottage range across Ontario — the charges and zoning rules below are specific to this city and differ in every municipality.
Prefab Cottage Models Available in Oshawa
My Own Cottage offers 33 preconfigured cottage plans from 505 to 3,373 square feet, priced from $229,500 to $949,500. The range spans prefab cabins and compact garden suites through to full-size modular homes and recreational homes, all custom built on your lot. Every plan is adjustable in layout, finishes and features before production, and we also work from custom plans where no model fits.
Compact Cottage Plans for Backyard and Secondary Units
These matter most in Oshawa, where the majority of enquiries concern a second unit behind an existing home.
Metric conversions matter because Oshawa’s zoning limits are written in square metres. Kingswood and Bay Breeze sit exactly on the 60 m² line — read the lot-coverage section before assuming either fits your property.
Full-Size Cottage Plans for a Build on Your Own Lot
- 988 SQ. FT
- Bedrooms: 2
- Bathrooms: 1
Preconfigured model starting at: $324,500
- 1170 SQ. FT
- Bedrooms: 3
- Bathrooms: 1
Preconfigured model starting at: $369,500
Pricing tracks specification rather than floor area alone — a smaller plan at a higher finish level can price above a larger, simpler one. See all 33 cottage plans with layouts and specifications.
Why Prices You See Elsewhere Aren’t Comparable
“Prefab” covers four different products, and their prices measure different things. Comparing them directly is the most common mistake Oshawa buyers make.
| What it is | What arrives | What’s still yours |
|---|---|---|
| Sleeping cabins and bunkies | An accessory structure, not a dwelling | Everything — these generally cannot be approved as living space |
| House kits | Materials and drawings | Assembly, all trades, all finishing |
| Panelized homes | A weather-tight shell erected on your prepared foundation | Interior partitions, mechanical, all finishing |
| Turnkey modular homes | A finished dwelling, set on a permanent foundation | Foundation, servicing, permits, site work |
A $15,000 sleeping cabin and a $229,500 turnkey modular home are not competing prices — they’re different products with different legal outcomes. The questions worth asking any supplier: what actually arrives, what remains yours to complete, and whether the finished result is legally a dwelling unit.
Understanding What a Prefab Cottage Costs in Oshawa
The model price is the predictable half of the budget. Compact plans start at $229,500; the largest is $949,500.
Everything tied to your specific property — foundation, excavation, site preparation, utility servicing, municipal permits and finishing — is quoted separately, because those costs are set by your lot rather than by the building.
Two of these numbers we can give you today. The third depends entirely on your lot — which is why we look at the property before quoting.
Cost predictability comes from separating the costs, not from blending them into one number. Site work is the part no builder can price from a floor plan, but it isn’t a mystery. Our guide to what site work typically costs across Ontario covers foundation, servicing and access, and how much each varies by lot.
What the Model Price Covers, and What It Doesn’t
| Included in the model price | Quoted separately for your property |
|---|---|
| Design and engineering for the selected plan | Land or lot purchase |
| Factory construction of the modules | Grading, clearing and excavation |
| Layout, finish and feature customization | Foundation |
| Standard specification as agreed | Water, sewer, hydro and gas utility servicing |
| Municipal permits and development charges | |
| Site finishing, landscaping and driveway work |
Delivery and installation scope is confirmed in writing on your individual quote, because delivery access differs so much between properties. Ask for that boundary in writing from any builder — vague inclusion language is where most prefab budgets go wrong.
Oshawa’s Development Charges
As of July 1, 2026, the City of Oshawa publishes a combined total of $130,682 per single detached unit in development charges and cash-in-lieu of parkland dedication. That is more than half the price of a compact cottage plan again, and it rarely appears in prefab advertising.
Most of this bill isn't the City's. The Region of Durham takes 58% — and $6,200 of the total isn't a development charge at all.
| Charge | Single detached, per unit |
|---|---|
| City of Oshawa | $40,720 |
| Region of Durham | $76,227 |
| Public school board | $4,349 |
| Separate school board | $3,186 |
| Cash-in-lieu of parkland dedication | $6,200 |
| Total | $130,682 |
Source: City of Oshawa, Residential Development Charges and Cash-in-lieu of Parkland Dedication, effective July 1, 2026.
What is and isn’t a development charge. Of the $130,682, development charges proper — City, Region and the two school boards — account for $124,482. The remaining $6,200 is cash-in-lieu of parkland dedication, a Planning Act instrument under By-law 63-2022, and the City notes it applies to areas outside of subdivisions only.
Three further things the table doesn’t tell you:
Most of it isn’t the City’s. The Region of Durham collects $76,227 — 58% of the total. The City collects $40,720, or 31%. Homeowners routinely direct their frustration at City Hall over a bill that is mainly regional.
It moves twice a year. City rates are indexed on January 1 and July 1 under Development Charge By-law 91-2024. Any figure you read — including this one — has an expiry date.
When it’s payable is not what you’d assume. The City’s schedule states these are payable on or before building permit issuance, but Note 9 on the same page states that City and Durham Region residential development charge payments are deferred until before first occupancy is issued. That is an unresolved contradiction on the City’s own page — confirm which governs with Building Services before you plan your draws.
There is one long-standing exemption area. The City has waived development charges for new housing in the Downtown Urban Growth Centre since 2004. If your property sits inside that boundary, the arithmetic on this page does not describe your project — confirm with Building Services.
In plain terms: a Fox Den at $229,500 built as a new dwelling on its own Oshawa lot attracts roughly $360,182 in home and municipal charges — before foundation, utility servicing or site preparation, and before any conservation, highway or transit corridor approvals.
Two Ways to Build in Oshawa — and $116,947 Between Them
The same prefab building can be legally two different things in Oshawa. Built as a new dwelling on its own lot, it attracts the full development charge. Built as an additional dwelling unit behind an existing house, it is exempt from City and Region development charges — the two largest lines on the bill.
Three questions decide whether Oshawa charges you $116,947 to build — or nothing at all.
The exemption is set out in section 2(3.2) of the Development Charges Act, 1997. It covers one residential unit in a building or structure ancillary to an existing detached, semi-detached or rowhouse, provided the existing house contains no more than two residential units and no other ancillary building on the lot contains a residential unit.
| What differs | Path A — ADU behind an existing home | Path B — New dwelling on its own lot |
|---|---|---|
| Legal category | Accessory apartment in an accessory building | Single detached dwelling |
| City + Region development charges | Exempt under the Development Charges Act — $116,947 | $116,947 ($40,720 + $76,227) |
| School board charges + parkland CIL | Not covered by that exemption — roughly $13,735 may still apply | $13,735 |
| Size limits | Three lot-coverage tests apply (below) | Zoning envelope for the lot |
| Utility servicing | Extends from the existing house | New connections required |
| Typical plans | Fox Den, Pine View, Willow | Full catalogue |
Path B isn’t a worse outcome — it’s a different project with a different set of constraints. If that’s your situation, our guide to building a permanent residence on your own Oshawa lot covers the zoning envelope, servicing connections and the full range of plans.
What the Exemption Does and Doesn’t Reach
The Development Charges Act exemption covers the City and Region portions — $116,947 of the total. It does not reach the other two instruments.
School board charges — $7,535. Education development charges are imposed separately under the Education Act and Ontario Regulation 20/98. The regulation’s intensification exemption is framed around additional dwelling units created within an existing residential building, with a floor-area test measured against the existing unit. A detached garden suite is a separate structure and does not obviously fall inside that class. Treat these as payable until the Durham District School Board and the Durham Catholic District School Board confirm otherwise in writing.
Parkland cash-in-lieu — $6,200. A Planning Act instrument, unaffected by the Development Charges Act exemption. The City notes it applies to areas outside of subdivisions only.
We run both checks during site coordination rather than assuming them.
Can You Put a Prefab Cottage in Your Oshawa Backyard?
Yes. Oshawa permits accessory apartments within accessory buildings, subject to Zoning By-law 60-94 — the full requirements are set out on the City’s accessory apartment page.
Permitted zones: R1 · R2 · R3 · R5 · OSR-A · OS-ORM · AG-A · AG-B · AG-ORM
A lot may contain a maximum of three residential dwelling units, of which a maximum of one may be in an accessory building.
Size is governed by three separate tests, not one — and on most lots the 60 m² figure people quote is not the binding constraint.
One thing worth clearing up first. Oshawa’s zoning by-law calls these accessory apartments. You will also see the same thing described as a garden suite, an ADU, an additional dwelling unit, a backyard suite or a secondary dwelling unit. They all describe one thing — a self-contained dwelling unit secondary to the main house, with its own toilet and cooking facilities — and Oshawa’s rules apply regardless of which term a supplier uses.
The Three Lot-Coverage Tests
Oshawa limits backyard suites three different ways — and the smallest limit wins. Which one that is depends on your lot, your house, and whether you already have a garage or shed.
Oshawa applies the most restrictive of the following to all accessory buildings on the lot combined:
Because the first test scales with your lot, it usually binds first. Here is the minimum lot area each compact plan needs to clear the 8% test on its own:
| Cottage plan | Footprint | Minimum lot area to pass the 8% test |
|---|---|---|
| Fox Den | 46.9 m² (505 sq ft) | 587 m² (6,318 sq ft) |
| Pine View | 50.2 m² (540 sq ft) | 627 m² (6,749 sq ft) |
| Willow | 52.4 m² (564 sq ft) | 655 m² (7,050 sq ft) |
| Kingswood / Bay Breeze | 60.0 m² (646 sq ft) | 750 m² (8,073 sq ft) |
| Modern Living | 66.7 m² (718 sq ft) | 834 m² (8,977 sq ft) |
| Lake View | 68.8 m² (741 sq ft) | 860 m² (9,257 sq ft) |
| Hideaway | 73.2 m² (788 sq ft) | 915 m² (9,849 sq ft) |
Assumes no other accessory buildings on the lot. Confirm your lot area and zone with the City.
Two consequences most buyers miss:
The second test cuts the same way. To reach a 60 m² accessory unit under the 50% rule, the house itself needs a ground-floor coverage of at least 120 m² (about 1,292 sq ft).
The tests cover every accessory building. An existing detached garage or a large shed consumes part of the allowance before your garden suite is drawn. Removing one is sometimes the difference between a 505 sq ft plan and no plan at all.
Height, Setbacks and Separation
Confirmed provisions for an accessory dwelling under Zoning By-law 60-94:
• Maximum height 4.5 m (14 ft 9 in) — or 5 m (16 ft 4 in) on properties zoned R1-G and R1-H. Measured from grade to the highest peak at the front elevation.
• Minimum 0.6 m (2 ft) setbacks from interior side and rear lot lines.
• On a corner lot, the exterior side setback is the minimum side yard depth required for the zone.
• Minimum 3 m between the main dwelling and the accessory building dwelling.
• Generally not permitted in the front yard.
Height is a real constraint on a prefab plan and it isn’t visible on a floor plan. We confirm the finished height of any cottage plan against the applicable limit before you commit to a design.
Parking, Walkway and Landscaping
One additional parking space is required for each accessory dwelling, on top of the two required for the existing home.
| Units on the lot | Spaces required | Street access |
|---|---|---|
| Two | 3 (each 2.75 m × 5.75 m) | Two spaces with unobstructed street access, not in tandem |
| Three | 4 (each 2.75 m × 5.75 m) | Three spaces with direct street access, not in tandem |
Also required:
• A hard-surface unobstructed walkway, minimum 0.81 m (32 in) wide, from the accessory unit’s entrance to the street line.
• A minimum of 50% of the front yard and 50% of the exterior side yard maintained as landscape open space — plus 50% of the rear yard on a corner lot.
• Curb cuts for street-accessible parking require approval from the City of Oshawa on city streets, or the Region of Durham on regional roads.
Parking is where many backyard suite plans quietly fail. Fitting a fourth required space while preserving half the front yard as landscaping is a genuine geometric constraint on a standard Oshawa lot.
Where an Accessory Dwelling Cannot Go
Certain locations rule out an additional dwelling unit regardless of size:
• Within hazard lands or areas without safe access as identified by the Central Lake Ontario Conservation Authority (CLOCA). This isn’t a parallel approval — it is written directly into the zoning test.
• Within 30 m of any railway right of way.
• Within 14 m of any Highway 401 or 407 property line.
• Within 7 m of the outer limit of any gas or oil pipeline corridor.
• Where the main dwelling is permitted only as an interim use under an “h” holding symbol.
If your property misses a requirement, a minor variance application through the City’s Committee of Adjustment is the route — not a redesign in isolation.
Approvals, in the Order They Actually Happen
Approvals run in sequence, and the building permit is the last step, not the first. Zoning conformity comes first; agency approvals follow or run alongside; the permit comes after. Ordering a factory build before zoning is confirmed is the most expensive mistake available.
1. Confirm zoning. Identify your property’s zone using the City’s mapOshawa tool, then check the applicable provisions in Zoning By-law 60-94.
2. Check other agencies. The City names three: CLOCA regulated lands, the Ministry of Transportation highway corridor controlled area, and Metrolinx transit corridors. Contact the relevant agency directly for a permit.
3. Prepare drawings. The City recommends a qualified professional — an architect, engineer or BCIN designer. For a new accessory building dwelling, a plan of survey sealed by an Ontario Professional Engineer or Ontario Land Surveyor is required.
4. Submit the building permit application through the City’s Application Portal, with the provincial Application to Construct or Demolish, Schedule 1, the plumbing information form, a site plan, and full floor plans, sections and elevations.
5. Build, deliver, install and inspect.
6. Register the unit. A two-unit house registration issues through the permit process, with the certificate arriving within 60 days of the building inspector’s final inspection.
If you are converting an existing outbuilding rather than adding a new one, section 5.12.1(q) provides a separate route for an accessory building that existed as of May 29, 2023, with the accessory apartment floor area not exceeding 60 m².
What “Prefab” Means Legally
Prefab is not a single legal category, and the distinction decides what you can build. A modular dwelling placed on a permanent foundation is assessed as a dwelling under the zoning by-law and the Ontario Building Code, the same as a site-built home.
Chassis-borne manufactured and mobile homes are a different product class with different rules. Factory-built construction procedures in Canada are certified against the CSA A277 standard, which covers work completed in the plant — it does not extend to transport, foundation or on-site erection, which remain subject to municipal inspection.
A structure marketed as a bunkie, cabin or guest cottage is not automatically an approved dwelling unit. Approval depends on how it is built, sited and permitted.
Getting a Module Into an Oshawa Backyard
Delivery access in an established Oshawa neighbourhood is a different problem from a rural lot. The module usually has to be craned over an existing house into the rear yard, from a residential street, past overhead service lines and mature trees.
We assess access before a plan is finalised, because it can determine module size, the number of sections, and occasionally the cottage plan itself.
Getting a module into a backyard usually means lifting it over the house. Crane position, service lines and tree canopy can decide which plan actually fits.
What we look at on a site visit:
• Crane access and reach — where a crane can legally and safely set up on the street, and whether its reach clears the existing house to the intended pad.
• Overhead lines — hydro, telephone and cable service drops to the existing home, and whether temporary de-energising is needed.
• Side-yard clearance — fence and gate removal, and whether a walk-in approach is viable instead of craning.
• Mature trees — rear-yard canopy is the most common reason a straightforward set becomes complicated.
• Street occupancy — closing part of a residential street for set day requires coordination.
None of this is unusual, and none of it is a reason not to build. It is a reason to assess delivery access early rather than after a deposit.
Why Off-Site Construction Suits Durham Region
Off-site construction builds the major components of your cottage in a controlled environment, then transports and assembles them on a prepared foundation. The practical advantages in Durham Region are schedule and consistency rather than a dramatically lower price.
• Weather-related delays are reduced. Framing, sheathing and interior work happen indoors, so the critical path doesn’t depend on an Ontario winter or a wet spring.
• Quality control is repeatable. Factory construction uses jigs, indoor storage and consistent crews, so the same detail is executed the same way every time.
• Material waste falls. Bulk purchasing and controlled cutting reduce offcuts and on-site theft or spoilage.
• Energy efficiency is easier to achieve. Airtightness and insulation continuity are simpler to control on a shop floor than in the open.
• Site preparation runs in parallel. Excavation and foundation work can advance while modules are in production, compressing the schedule against a strictly sequential build.
What off-site construction does not change is your lot. Excavation, foundation, utility servicing and municipal permits cost the same regardless of how the building above them was made.
Financing a Prefab Build in Oshawa
Oshawa is one of the more straightforward places in Ontario to finance prefab homes, because these are year-round primary residences on serviced urban lots. A prefabricated home permanently affixed to a permanent foundation is generally assessed under standard mortgage underwriting rather than as a chattel.
Lending programs designed for factory-built housing typically require full-time, year-round occupancy and year-round vehicular access — conditions an Oshawa build meets and a seasonal recreational property does not.
Two Things That Come Up in Nearly Every Consultation
1. Lenders need a defined project total.
When land, building, foundation and site work are priced separately, buyers struggle to present one number. A scoped quote showing the cottage plan price, a site-work allowance and the municipal charges as separate lines is far more productive than an approximate range.
2. Confirm when the charges are actually payable.
The City’s schedule states development charges are payable on or before permit issuance, while Note 9 on the same page states City and Region residential payments are deferred until before first occupancy. Confirm which applies to your project with Building Services and build it into your draw schedule — the difference can be several months.
We are not a lender and cannot approve financing. What we can give you is the scoped figures a lender will ask for.
How We Work
Four stages under one project management team, with property assessment front-loaded so surprises surface before money is committed. Design, permit coordination, site coordination, factory construction, delivery and installation and licensed-trade installation are handled together rather than across several providers.
1. Consultation. We review your property, intended use, size requirements, budget range and timeline — including which of the two legal paths applies to you.
2. Custom cottage design. Choose a plan or start from custom plans, then refine layout, finishes and features. Decisions here define the production scope.
3. Site coordination and approvals. Zoning conformity, agency approvals, foundation design, utility servicing, delivery access and municipal permits — resolved before production begins.
4. Build, deliver and install. Factory construction proceeds while approved site preparation advances; the cottage is transported, set and completed on the prepared foundation by licensed trades.
If You’re Looking for a Lake Cottage
Oshawa’s Lake Ontario frontage is largely regulated shoreline and working waterfront rather than recreational cottage frontage.
Buyers in Durham Region wanting seasonal or year-round recreational homes generally build north of the city. If that’s you, our cottage options around the Kawartha lakes and near Pigeon Lake and the Trent–Severn are a better fit — different lots, different rules, different budget shape.
Prefab Cottages Oshawa: Frequently Asked Questions
How much do prefab cottages cost in Oshawa?
Cottage plans start at $229,500 for a compact model and run to $949,500 for the largest. Property costs are quoted separately and can be substantial: foundation, excavation, utility servicing, municipal permits and development charges. A new dwelling on its own lot currently attracts $130,682 in development charges and parkland cash-in-lieu in addition to the model price.
Are there affordable prefab cottages in Oshawa?
It depends what you’re comparing. Our compact cottage plans start at $229,500 for a finished, turnkey dwelling — a different product from a $15,000 shed-style cabin, which cannot be approved as living space. The larger lever in Oshawa is usually the legal path rather than the plan: building as an additional dwelling unit removes $116,947 in City and Region development charges.
How do I choose a prefab cottage builder in Oshawa?
Check three things before comparing designs. Is the builder licensed with the Home Construction Regulatory Authority (HCRA) and enrolled with Tarion? Will they put the delivery and installation boundary in writing? Will they assess your lot’s zoning before quoting? The Ontario Builder Directory lets you verify licensing status and warranty coverage in minutes — search any builder by name. My Own Cottage is HCRA-licensed and Tarion-enrolled.
Can I buy a prefab cottage as a kit and assemble it myself?
Yes. Alongside the turnkey route, we offer a kit option where the prefab ships as a package for self-builders. The trade-off is scope: a kit shifts assembly, trades and finishing to you. The regulatory requirements don’t change either way — the City still requires the same zoning conformity, drawings, municipal permits and inspections whichever route you choose.
Who handles site preparation and the foundation for a prefab cottage?
Site preparation, excavation, foundation and utility servicing are property-specific and quoted separately from the cottage plan. We coordinate the sequence — foundation design, servicing, delivery access and municipal permits — and work with licensed trades to carry it out, so factory construction and site work can run in parallel rather than one after the other.
Do you pay development charges on a prefab home in Oshawa?
Yes, if you are creating a new dwelling unit on its own lot — $130,682 per single detached unit as of July 1, 2026, comprising $124,482 in development charges and $6,200 in cash-in-lieu of parkland. A qualifying additional dwelling unit behind an existing house is exempt from the City and Region portions, $116,947, under section 2(3.2) of the Development Charges Act. School board charges and parkland cash-in-lieu are separate instruments and are not covered by that exemption.
How big can a backyard cottage or ADU be in Oshawa?
Oshawa applies the most restrictive of three tests to all accessory buildings combined: 8% of total lot area, 50% of the house’s lot coverage, or 60 m² of ground floor area (90 m² in R1-G and R1-H zones). On lots under about 750 m², the 8% test is usually the binding one — often well below 60 m².
What’s the difference between an ADU and a garden suite in Oshawa?
There is no legal difference. Oshawa’s Zoning By-law 60-94 uses the term “accessory apartment” for a self-contained dwelling unit secondary to the main house. Garden suite, ADU, additional dwelling unit, backyard suite and secondary dwelling unit are all informal names for the same thing, and the same zoning provisions apply to each.
Do I need a building permit for a prefab cottage in Oshawa?
Yes. Municipal permits are required, and zoning conformity must be confirmed first. Depending on your property, approvals may also be needed from the Central Lake Ontario Conservation Authority, the Ministry of Transportation or Metrolinx before the permit is issued. Applications are submitted through the City’s online portal.
How do people finance a prefab garden suite in Oshawa?
Because a garden suite is built on land you already own, the usual routes are a mortgage refinance, a home equity line of credit, or a construction loan drawn in stages — rather than a purchase mortgage. Whichever route you take, lenders will want a scoped quote separating the cottage plan price, the site work and the municipal charges. Confirm your options with your lender or a mortgage broker.
Can you get a mortgage on a prefab home in Ontario?
Generally yes. Modular homes permanently affixed to a permanent foundation are typically assessed under standard mortgage underwriting rather than as a chattel. Programs designed for factory-built housing usually require full-time, year-round occupancy and year-round vehicular access — conditions an Oshawa build on a serviced lot meets. Confirm eligibility with your lender.
How long does a prefab cottage project take in Oshawa?
Timing depends on design approval, agency approvals, permit review, site preparation, factory construction, delivery and installation. Factory construction can run in parallel with approved site work, which compresses the overall schedule against a strictly sequential build. Approvals, not construction, are usually the variable stage.
Are prefab cottages cheaper than building on site?
Not automatically. Off-site construction improves cost predictability, reduces weather-related delays and cuts material waste, but your lot costs the same either way — excavation, foundation, utility servicing and municipal permits are property-driven, not method-driven. Most buyers report predictability as the clearest advantage rather than a dramatically lower total.
Talk to Us About Your Oshawa Property
Before choosing between cottage plans, establish which of the two legal paths your property is on and whether it passes the three lot-coverage tests. That determines your budget more than any design choice.
Bring your address, lot dimensions, a survey if you have one, and the intended use. We’ll confirm the applicable zone, run the coverage calculations, and give you a scoped figure covering the cottage plan, the site work and the municipal charges as separate lines.
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How We Verified the Figures on This Page
Every charge, dimension and regulatory provision above comes from a primary source — the City of Oshawa’s own published schedules and by-laws, or Ontario legislation. Nothing on this page is drawn from competitor websites, industry blogs or general estimates.
What we checked, and against what:
| Figure or provision | Source | As of |
|---|---|---|
| $130,682 total, and its five-line breakdown | City of Oshawa, Residential Development Charges and Cash-in-lieu of Parkland Dedication schedule | July 1, 2026 |
| Development charge indexing and payment timing | Development Charge By-law 91-2024 | July 1, 2026 |
| ADU exemption from City and Region charges | Development Charges Act, 1997, s. 2(3.2) | In force, checked August 2026 |
| School board charges | Education Act s. 257.54 and O. Reg. 20/98 | Checked August 2026 |
| Parkland cash-in-lieu | City of Oshawa By-law 63-2022 | July 1, 2026 |
| Lot coverage, height, setbacks, parking, walkway, prohibited locations | Zoning By-law 60-94, ss. 5.1 and 5.12, via the City’s accessory apartment requirements | Checked August 2026 |
| Model floor areas and starting prices | My Own Cottage current catalogue | August 2026 |
What we did not verify, and can’t. Sean Stevenson is not a lawyer, lender or municipal planner. Zoning applies at the parcel level, and your property’s zone, lot area, existing accessory buildings and any conservation, highway or transit corridor overlays will determine what you can actually build. Lending program eligibility is set by your lender. Confirm both before committing.
What is still open. Two things on this page could change:
• Whether school board charges apply to a detached garden suite. The education development charge exemption is framed around units created within an existing residential building, so we treat the school charges as payable and are seeking written confirmation from the Durham District School Board and the Durham Catholic District School Board.
• Whether Oshawa’s development charges are reduced. The City has applied to the Canada–Ontario Development Charge Reduction Program, which requires participating municipalities to cut residential development charges by 30–50% for at least three years. If an agreement is concluded, the figures above will fall.
When we re-check. City rates are indexed every January 1 and July 1, so this page is reviewed on that cycle and the verification date updated. If you find a figure that has moved, tell us at [email protected] and we’ll correct it.
Last verified: August 6, 2026.
About the Author
Sean Stevenson is Chief Marketing Officer and Buyer Experience Lead at My Own Cottage Inc., an HCRA-licensed, Tarion-enrolled prefab home builder based in Orillia, Ontario.
Sean has spent five years guiding Ontario buyers through the full prefab cottage process alongside My Own Cottage’s build team — lot assessment, all-in budgeting, zoning, municipal permits, development charges and final occupancy — across Muskoka, Simcoe County, Durham Region and the GTA. He writes about the part most buyers underestimate: what a factory-built cottage actually costs once the foundation, servicing and approvals are counted.