Published 2 November 2026 · By Jatin Dua, Broker of Record, RE/MAX Quantum Realty
Building a fourplex in Toronto often costs about $1.2 million to $2.4 million for 3,000 to 4,000 square feet before land, using the ULI Toronto panel range of $300 to $450 per square foot plus contingency and soft costs. Most extra units are exempt from development charges. Buying depends on the lot and rents.
This guide is for Toronto homeowners, investors and families who are thinking about building or buying a fourplex, a house with four separate units. You will get the rules, cost ranges from named and dated sources, worked examples checked with a calculator, and the fees and taxes people forget. Every figure is a range, because no two lots or houses cost the same.
Can you build a fourplex in Toronto?
Yes. Since May 2023, Toronto’s Official Plan and zoning bylaw allow buildings with up to four units in residential zones across the whole city. You do not need a rezoning for a fourplex. You need a building permit and a design that meets the zoning rules for your lot.
Key rules from the City of Toronto:
- Zones: fourplexes are allowed in the R, RD, RS, RM and RT zones, and you can convert an existing house.
- Stacked units: at least one unit must be fully or partly above another. Side-by-side units fall under townhouse or semi-detached rules instead.
- Height: limits are in metres. Where the height overlay shows less than 10 metres, a multiplex can go to 10 metres.
- Floor space: the usual floor space index limit in the zone label does not apply to multiplexes, although a Chapter 900 site exception may still apply.
- Parking: since 3 February 2022, fourplexes do not have to provide parking.
Sixplexes are a separate case. As of November 2026 they are only permitted in Toronto and East York District and Ward 23 (Scarborough North). My guide on buying land to build a multiplex covers lots for larger projects.
How much does it cost to build a fourplex in Toronto?
There is no official average. What you can use are construction cost ranges per square foot from named sources, then multiply by your building size. Here are the best Toronto-area figures I could verify:
| Cost item | Range | Source and date |
|---|---|---|
| Multiplex conversion, hard construction cost | $300 to $450 per sq ft | ULI Toronto panel for the City, April 2022 |
| Contingency on top of hard cost | 15% | ULI Toronto panel, April 2022 |
| Soft costs (design, engineering, financing, fees) | 20% | ULI Toronto panel, April 2022 |
| 3-storey stacked townhouse, GTA, new build | $180 to $270 per sq ft | Altus Group 2026 Canadian Cost Guide (as at 31 Jan 2026) |
| Wood-frame condo up to 6 storeys, GTA | $210 to $330 per sq ft | Altus Group 2026 Canadian Cost Guide |
| Custom-built single family house, GTA | $500 to $1,130 per sq ft | Altus Group 2026 Canadian Cost Guide |
Source: ULI Toronto, Multiplex Housing Financial Feasibility Exercise (April 2022); Altus Group, 2026 Canadian Cost Guide. Altus figures exclude GST/HST, site development and unfinished basement and garage area.
Altus does not publish a “fourplex” category. A new fourplex sits somewhere between a stacked townhouse and a small wood-frame apartment building, and custom-quality finishes push it higher. The ULI numbers were built for multiplex projects in Toronto, but they are from 2022, so treat them as a floor, not today’s price.
What does a fourplex cost on a real Toronto lot? Worked examples
Here is a simple way to turn those ranges into a budget. I checked the math with a calculator script. These are illustrations, not quotes.
| Building size (above grade) | Hard cost at $300–$450/sq ft | With 15% contingency and 20% soft costs added | Altus 6-storey wood-frame range ($210–$330/sq ft), for comparison |
|---|---|---|---|
| 3,000 sq ft | $900,000 to $1,350,000 | $1,215,000 to $1,822,500 | $630,000 to $990,000 |
| 4,000 sq ft | $1,200,000 to $1,800,000 | $1,620,000 to $2,430,000 | $840,000 to $1,320,000 |
Source: my calculation using ULI Toronto (April 2022) and Altus Group 2026 cost ranges. I added contingency and soft costs as percentages of hard cost to keep it simple. Land is not included.
So a mid-size new fourplex in Toronto can run from under $1 million to well over $2 million to build, before you pay for the land. The spread is wide because foundations, basements, servicing and finishes vary so much.
The ULI panel also ran two full scenarios that show the whole picture, including the house you start with:
- Smaller conversion: a house worth $1,500,000, turned into about 2,945 sq ft of rentable space. Total conversion cost $1,530,500, including $275,000 for approvals and permits.
- Larger conversion: a house worth $2,000,000, turned into about 5,092 sq ft of rentable space. Total conversion cost $2,620,800, including $450,000 for approvals and permits.
Those approval figures were set in 2022, before Toronto widened its development charge exemptions for small multiplexes, so today’s fees may be lower.
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What fees and charges does the City of Toronto add?
City fees are small next to construction, but they are real. Here are the 2026 numbers I could confirm:
| Fee | 2026 amount | Example: 4,000 sq ft (about 372 m²) new fourplex |
|---|---|---|
| Building permit, new residential construction | $18.56 per m² | About $6,897 |
| Residential unit fee | $56.33 per new unit | $225 for 4 units |
| Alterations and renovations, residential | $13.41 per m² | Applies to conversions instead |
| Minimum permit fee | $214.79 | Any project |
Source: City of Toronto, Building Permit Fees, effective 1 January 2026. Example is my calculation, about $7,122 in total.
Development charges (DCs) are the big one people worry about. Under provincial law, creating additional units in existing and new residential buildings is exempt as prescribed. On top of that, Toronto’s DC bylaw exempts the second through sixth units in developments of up to six units, effective 24 July 2025. Toronto also gives credits when you redevelop land that already had a home on it.
Whether any DC applies to your project depends on what is on the lot now and how the units are created, so get Toronto Building to confirm before you buy. My development charges guide explains how DCs work across the GTA.
How much does it cost to buy an existing fourplex in Toronto?
I could not find a published, reliable average price for fourplexes in Toronto, so I will not give one. TRREB’s public data does not break out fourplexes as their own category.
What I can show is the starting point for most conversions: the price of a detached house in the district.
| Toronto district (TRREB) | Detached median sold price, Jan–Oct 2026 | Change vs same period 2025 |
|---|---|---|
| E09 (Scarborough) | $866,500 | −7.8% |
| W03 | $882,500 | −6.4% |
| W04 | $995,000 | −7.1% |
| W06 (south Etobicoke) | $1,179,000 | +1.6% |
| C02 | $2,375,000 | −8.6% |
Source: TRREB MLS data via REALM, January–October 2026 vs the same period of 2025. Medians for detached homes, not fourplexes.
A legal fourplex usually sells above a single house in the same area, because it has more income. How much more depends on the rents, the condition and whether every unit is legal and permitted. Always ask for the permits and the final inspection records for each unit.
What rent can a Toronto fourplex earn?
Rent sets the value of a fourplex, so test it early. TRREB’s Q2 2026 rental report put the average GTA condo apartment rent at $2,273 for a one-bedroom and $3,013 for a two-bedroom, both lower than a year earlier.
As a rough illustration only: two one-bedroom and two two-bedroom units at those averages would bring in about $10,572 a month, or $126,864 a year, before vacancy and expenses. Units in a house are not condo units, and basement units often rent for less, so get local rent comparisons for your street.
The ULI panel found that multiplex projects work best in areas with higher rents and depend on charging market rent. Remember new units first occupied after 15 November 2018 are exempt from Ontario’s rent increase guideline, which is 2.1% for 2026 and 1.9% for 2027.
What taxes and financing rules apply to a fourplex?
- Property tax. MPAC treats apartment buildings with six or fewer units as residential, so a fourplex is taxed at Toronto’s residential rate of 0.767311% for 2026, not the higher multi-residential rate.
- GST/HST. If you build or substantially renovate housing to rent, the CRA usually treats you as a builder who must account for GST/HST on the fair market value when the units are first rented. The enhanced purpose-built rental rebate gives a 100% rebate of the GST (or federal part of HST) for buildings with at least four units, each with its own kitchen, bathroom and living area, where at least 90% are held for long-term rent. Construction must start after 13 September 2023 and before 2031. A fourplex can qualify, but only if all four units are long-term rentals.
- Mortgage insurance. Insured (high-ratio) mortgages are only available on purchases under $1,500,000, and many Toronto fourplexes cost more than that, so plan for at least 20% down on a conventional loan. My CMHC MLI Select guide covers the program built for multi-unit rentals.
The GST/HST self-supply rule catches owners who build a fourplex, live in one unit and rent the other three. Because not all units are long-term rentals, the 100% purpose-built rental rebate may not apply, and tax can still be owed on the value of the whole building. Talk to an accountant who knows real estate before you sign a construction contract.
For most of my clients, converting a solid existing house is cheaper and faster than knocking down and building new, but only if the house has good ceiling heights, a sound foundation and room for separate exits. Before buying, I get a designer to sketch four units on the actual floor plan and price the electrical and fire separation work first. If the rent will not cover the carrying cost at today’s rates, I walk away, no matter how good the lot looks.
What to do next
- Check your lot’s zone, height overlay and any Chapter 900 exception on the City’s interactive zoning map.
- Get a designer’s concept plan for four units and two or three contractor estimates on that plan.
- Ask Toronto Building to confirm development charges and permit fees for your exact project.
- Talk to an accountant about GST/HST and to a lender about financing before you commit.
- Compare a fourplex with a smaller project in my guide to buying a duplex or triplex in Toronto, or read buying a teardown to build if you plan to start from scratch.
Need help with this? Talk to me.
I’m Jatin Dua, Broker of Record at RE/MAX Quantum Realty, and I’m the best agent to do this kind of work for you in Toronto and across the GTA. Over $100 million in GTA sales and 100+ families helped sell. Feel free to contact me any time: call or text 833-330-1925 or email [email protected].
Frequently asked questions
How much does a fourplex cost to build in Toronto?
A new or converted fourplex in Toronto often costs about $1.2 million to $2.4 million to build for 3,000 to 4,000 square feet, before land. That uses the ULI Toronto panel’s $300 to $450 per square foot (April 2022) plus 15% contingency and 20% soft costs. Real quotes depend on the house and lot.
Can I build a fourplex anywhere in Toronto?
You can build a fourplex in Toronto’s residential zones (R, RD, RS, RM and RT) across the city, without a rezoning, since May 2023. You still need a building permit and must meet zoning rules such as height, setbacks and lot coverage. Check your lot on the City’s interactive zoning map first.
How much does a fourplex cost to buy in Toronto?
There is no reliable published average price for Toronto fourplexes, because TRREB data does not track them as a separate type. As a starting point, detached medians in Toronto districts ranged from $866,500 to $3,627,500 in January to October 2026 (TRREB via REALM). A legal fourplex usually sells above a single house nearby.
Do you pay development charges on a fourplex in Toronto?
Usually not on the extra units. Ontario law exempts additional units in existing and new residential buildings as prescribed, and Toronto’s bylaw exempts the second to sixth units in developments of up to six units, effective 24 July 2025. Confirm any charge on the first unit with Toronto Building before you buy.
What is the building permit fee for a fourplex in Toronto?
Toronto’s 2026 permit fee for new residential construction is $18.56 per square metre, plus $56.33 for each new unit. A 4,000 square foot (about 372 square metre) new fourplex would pay about $7,122. Conversions are charged the alteration rate of $13.41 per square metre instead.
Is a fourplex taxed as residential or commercial in Ontario?
A fourplex is taxed as residential in Ontario. MPAC includes apartment buildings with six or fewer units in the residential class. In Toronto, that means the 2026 residential rate of 0.767311% of assessed value, not the multi-residential rate of 1.208792% used for larger rental buildings.
Does a fourplex qualify for the GST rental rebate?
A fourplex can qualify for the 100% GST purpose-built rental rebate if each of the four units has its own kitchen, bathroom and living area, at least 90% of units are held for long-term rent, and construction started after 13 September 2023 and before 2031. In practice, all four units must be long-term rentals.
Is it cheaper to convert a house or build a new fourplex?
Converting a suitable existing house is often cheaper than building new, but it depends on the house. The ULI Toronto panel found construction cost, approvals and achievable rent decide feasibility. Houses with low ceilings, weak foundations or no room for separate exits can cost as much as new construction.
Do I need parking for a fourplex in Toronto?
No. Since 3 February 2022, duplexes, triplexes and fourplexes in Toronto do not have to provide parking spaces on the property. You can still choose to add parking if the zoning allows it. Skipping parking can free up space and lower costs, but check what local renters in your area expect.
Sources
- City of Toronto: Considerations when building multiplexes
- ULI Toronto: Multiplex Housing Financial Feasibility Exercise (April 2022)
- Altus Group: 2026 Canadian Cost Guide
- City of Toronto: Building permit fees (2026)
- City of Toronto: Development charges overview and exemptions
- MPAC: Residential property assessments
- TRREB Rental Market Report, Q2 2026
- CRA RC4231: GST/HST New Residential Rental Property Rebate
Related reading
- Converting a House to a Triplex in Toronto: Cost, Permits and Payback
- Multiplex Benefits for Toronto Homeowners: Rent, Value and Family Living
About the author — Jatin Dua, Toronto and GTA real estate broker
I am Jatin Dua, Broker of Record and co-founder of RE/MAX Quantum Realty Inc., Brokerage, Unit 101, 799 The Queensway, Toronto. I work with buyers and sellers across Toronto and the GTA and have helped more than 100 families sell. Four-plus years of active GTA transactions and over $100 million in sales volume.
Reach me at [email protected] or 833-330-1925, or book a call.