Family owned since 2007Ajax · Durham Region · Greater Toronto Area4.9 on Google
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james@jarviscontracting.ca(289) 892-4169Home additions & renovations
Durham Region & the Greater Toronto Area
A basement rec room with a vertical-panelled media wall, oak floating shelves with brass sconces, a long oak and stone ledge and a black coffee table

Our expertise

Basement renovations

Finished basements and legal second units, built to the code the inspector checks.

Let’s talk about your home
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We price basement finishing at about $55 to $90 per square foot in 2026, and a full legal basement apartment at $80,000 to $180,000, before HST. A legal unit has to meet the Ontario Building Code's rules for secondary suites, such as a 1.95 m ceiling and a fire separation between the units, and pass your town's inspections.

What's included

Straight-on view of the arched wet bar: dark panelled back, one shelf, two brass-rimmed round sconces, a brass faucet and cream lower cabinets

Every job, start to finish

  1. A check of ceiling height, exits and windows before design
  2. Floor plans and finishes with our designer
  3. Permit drawings, and the application for a second unit
  4. Fire separation and sound between units
  5. Egress windows and separate entrances
  6. Bathrooms, wet bars and laundry

The kinds of job

  • Basement finishing: rec rooms, bedrooms, bathrooms, bars and laundry
  • Legal second units
  • Separate entrances and walkouts
  • Opening up a basement by moving walls
Typical duration
Set after the first site visit
Permits involved
  • A building permit for a second unit, and for plumbing or structural work
  • The Building Code's secondary-suite rules: ceiling heights and a fire separation between units
  • Registration of the unit where the town requires it, such as Whitby
  • No development charges for a second or third unit in an existing house
  • Electrical work by a licensed electrical contractor, who files a notification with the Electrical Safety Authority

What it costs

Our 2026 ranges, not quotes. Every job is priced after a site visit, and the first estimate is free.

WorkRangeBasisSource
Full legal basement apartment$80,000 to $180,0002026. Before 13% HST.Our 2026 price
Basement bathroom$25,000 to $50,0002026; the top end when new plumbing goes under the slab. Before 13% HST.Our 2026 price
Basement finishing$55 to $90per sq ft2026, by finish level. Before 13% HST.Our 2026 price
Legalising an already-finished basement$45,000 to $95,0002026. Before 13% HST.Our 2026 price
Separate side-door entrance$18,000 to $28,0002026. Before 13% HST.Our 2026 price
Underpinning the full perimeter$60,000 to $120,0002026, when the ceiling is too low. Before 13% HST.Our 2026 price

What moves the number

  • Ceiling height, and whether the floor has to be lowered or underpinned
  • A second unit or not: fire separation, a second exit, a kitchen
  • A separate entrance or a walkout
  • Bathrooms and how far the plumbing runs
  • Moisture or water damage found when the walls open
  • Finish level, and 13% HST on top

Finished jobs

Basement renovations

A finished basement is a renovation. A legal second unit is a permitted, inspected apartment that meets the Building Code's secondary-suite rules: ceilings at least 1.95 m, 1.85 m under beams and ducts, and a fire separation between the units, which can be a continuous smoke-tight layer of 15.9 mm Type X drywall (2024 Building Code Compendium). Turning one unit into two needs a permit even if you build nothing (Building Code Act). Our legal basement requirements guide lists the rest.

A full legal basement apartment runs $80,000 to $180,000 with us in 2026, and legalising a basement that's already finished about $45,000 to $95,000, before HST. A separate side entrance is about $18,000 to $28,000 on its own, and a bathroom $25,000 to $50,000, more when new plumbing goes under the slab. Our legal basement cost guide breaks it down.

Does a basement apartment pay development charges?

No. A second or third unit inside an existing house is exempt from development charges (Development Charges Act). Some towns ask you to register it: Whitby charges $268 (Town of Whitby).

Do I need a permit to finish my basement?

Your town's building department decides, and the answer turns on what you're building: a second unit always needs one, and so does plumbing or structural work. Our basement permit guide covers each Durham town.

Real work

Stone Ridge, in Scarborough, is a finished basement with a rec room and panelled media wall, an arched wet bar, a bathroom, a laundry and a bedroom. One client, whose basement had been a storeroom for twenty years, wrote that the job "doubled the size of the living area in our home" (Tony O'Brien, Google review).

Where we do this

In Ajax, Aurora, Brampton, Brock, Burlington, Caledon, Clarington, East Gwillimbury, Georgina, Halton Hills, King, Markham, Milton, Mississauga, Newmarket, Oakville, Oshawa, Pickering, Richmond Hill, Scarborough, Scugog, Toronto, Uxbridge, Vaughan, Whitby and Whitchurch-Stouffville.

How the job runs

  1. Meet James

    James meets you at the house, hears what you want and gives you a rough estimate on the spot. The first estimate is free.

  2. Proposal and contract

    If the estimate works for you, James prepares a detailed proposal. The whole project is priced, and the contract signed with a 10% deposit, before any design work begins.

  3. Design onboarding

    Our designer sends you an onboarding email with some homework: your style, how your family uses the house, and what you need and want. You share Pinterest boards, then go through them together on a Zoom call: what you like in the pictures, and what you don't.

  4. Measure and floor plans

    The designer measures the house and draws the floor plan: which walls come out, where the stairs land, how new space joins the old. We go through it with you until it's confirmed.

  5. Drawings and 3D rendering

    With the plan confirmed, she draws the elevations and the millwork, then puts it all into a 3D rendering, so you see the rooms before anyone orders a cabinet.

  6. Finishes presentation

    We don't take you round the stores: there are too many options. Using what she learned in onboarding, the designer narrows the tile, flooring, quartz, plumbing fixtures and the rest to a few choices that suit your style, collects the samples and presents them to you in our office. If a selection changes the price, the change goes through a change order you sign.

  7. Permits and engineering

    We prepare the permit drawings, bring in the structural engineer wherever a beam or a load changes, and apply to the municipality. If the plan changes after the permit is issued, we file the amendment.

  8. Construction

    Our crew and trades build it, with one point of contact from demolition to the last coat of paint. Our site supervisors write a job log every day, which you can follow in our online app. When we open a wall and find a problem, you hear about it, and what it costs, before we fix it.

  9. Inspections

    The municipal building inspector checks the work at each stage the permit sets, before it gets covered up.

  10. Handover

    We walk the finished house with you and put right anything that isn't. On one job a stair stain didn't match the new floor, so we refinished the stairs.

Credentials

Jarvis Contracting Inc. BBB Business ReviewBBB ratingA+View profile ↗

Questions

What makes a basement apartment legal in Ontario?

A legal basement apartment in Ontario has a building permit, passed its inspections and meets the Building Code's secondary-suite rules, including minimum ceiling heights and a fire separation between the units. Some towns, such as Whitby, also require the unit to be registered.

What ceiling height does a basement apartment need in Ontario?

The 2024 Ontario Building Code requires ceilings of at least 1.95 m in a secondary suite, with at least 1.85 m of clear height under beams and ducts. Basements lower than that need the floor lowered or the walls underpinned before they can become a legal unit.

How much does a legal basement apartment cost in Ontario?

We price a full legal basement apartment at $80,000 to $180,000 in 2026, and legalising an already-finished basement at about $45,000 to $95,000, before HST. A separate entrance adds about $18,000 to $28,000 on its own, and underpinning more again.

Do I pay development charges on a basement apartment?

No. Ontario's Development Charges Act exempts a second or third unit created inside an existing house, within the three-unit limits. You still pay the building permit fee, and in towns like Whitby a registration fee of $268.

Guides

Sources

  1. 2024 Building Code Compendium publications.gov.on.ca
  2. Building Code Act ontario.ca
  3. Development Charges Act ontario.ca
  4. Town of Whitby whitby.ca