The way in
Separate entrance
A new exterior door cut into the foundation, with the stairwell, guard and drainage designed so the opening does not weaken the wall.
- Foundation opening design
- Stairwell & drainage
- Guards & lighting
- Frost & waterproofing
Legal Basements
A basement apartment the city signs off on.
A second unit with its own entrance, fire separations, egress and heating, designed, permitted and built by one team. The Vaughan unit on our project list is one: code-compliant, with its own entrance, and bringing in rent.
- Building
designs - 200+
- Years of
practice - 10
- Trusted
partners - 20+
- Recent project
- Vaughan · 1,100 sq ft
- Drawn & stamped
- In-house, one P.Eng and BCIN team
- Service area
- GTA, within 90 minutes of Richmond Hill
- First consultation
- Free, by phone or on site
What’s included
Scope: what we take on, and what each part includes.
A legal unit is a list of code items, and the inspector checks each one. We design to that list, build to it, and book the inspections in the order the city wants them.
What the inspector checks first
Fire separation & egress
Rated ceilings and walls between the units, interconnected smoke alarms, and bedroom windows or doors large enough to get out through.
- Fire-rated assemblies
- Egress windows
- Interconnected alarms
- Sound separation
The wet side
Kitchen & bathroom
Plumbing for a second kitchen and bathroom, tied into drains that were never meant for them, with venting and hot water sized for two units.
- Kitchen & bath layouts
- Drain & vent tie-ins
- Hot water for two units
- Bathroom ventilation
Through to occupancy
Inspection scheduling
The inspections the permit calls for, booked as each stage is ready, and the paperwork closed so the unit is legal on paper as well as in fact.
- Framing & insulation inspections
- Plumbing & electrical inspections
- HVAC & final
- Permit close-out
The package
When you need it, and what you get.
Find your situation below. If it’s there, this is the service, and the card underneath is everything you get from our one office.
You need this when
06 common situations
- Rental incomeFrom an empty basement
- Space for familyA place of their own
- Buying a houseLegalize the basement before you close
- City noticeAbout an unpermitted unit
- Low ceilingIs underpinning worth it?
- One contractorDrawings, permit and build
- Not sure it applies?Tell us about it on a free call and we’ll say whether this is the right service.
What you get
07
items in your package, all from one P.Eng and BCIN team.
Drawn & stamped in-house
- Site visitHeight, egress and entrance checked
- Permit drawingsLayout, fire separations, structure, HVAC
- Building permitFiled and followed to issue
- Entrance & fire assembliesFramed, insulated and fire-rated
- Plumbing, electrical, HVACInstalled and inspected
- Kitchen & bathroomAnd the finishes
- A legal unitPermit closed, ready to list and insure
How it runs
Process: 4 steps from first call to sign-off.
Four steps from a bare basement to a closed permit, with the inspections built into the schedule.
Site visit & code check
We measure the ceiling, look at the windows, the entrance options and the mechanical room, and tell you whether the basement can be made legal and what it will take.
Design & permit
Layout, separations, the structural opening and HVAC are drawn in one office and filed with the municipality. City comments are answered at no extra charge.
Build
Entrance, framing, rough-ins, insulation and rated assemblies go in, inspected at each stage.
Finish & close out
Kitchen, bathroom, flooring and doors, then the final inspection and the closed permit.
- Property address
- Basement ceiling height, measured floor to joist
- Photos of the basement, the mechanical room and the outside wall where an entrance could go
- Any existing drawings or a previous permit
- Whether the unit is for family or for rent
Case files
Our Projects: real permits, real builds, real value added.
Open any file for the scope, the disciplines involved, what we delivered and what the owner came away with.
- Files
- 08
- Municipalities
- 07
A compact two-storey suite in a Toronto backyard. Architectural and structural drawings, zoning review and a framing package that makes every square foot count.
- Location
- Toronto
- Area
- 700 sq ft
- Sector
- Residential
- Disciplines
- Architectural · Structural
Delivered
- Architectural drawings
- Structural framing design
- Zoning review
- Building permit application
New living space on a lot the owners already had.
Start a project like this
Structural walls came out and rooms were added to open the plan. Beam and column design, permit drawings and renovation coordination through to final inspection.
- Location
- Richmond Hill
- Area
- 2,700 sq ft
- Sector
- Residential
- Disciplines
- Structural · Architectural
Delivered
- Load-bearing wall removal
- Beam & column design
- Permit drawings
- Renovation coordination
An open layout where the load-bearing walls used to be.
Start a project like thisA code-compliant second unit with its own entrance, fire separations between the units, HVAC design and the full permit package.
- Location
- Vaughan
- Area
- 1,100 sq ft
- Sector
- Residential
- Disciplines
- Architectural · Mechanical · Fire safety
Delivered
- Separate entrance
- Fire separations
- HVAC design
- Full permit package
A legal second unit that brings in rent and adds property value.
Start a project like this
A new build taken from the client’s sketch to occupancy, with the architectural, structural and mechanical design done by one team.
- Location
- Haldimand County
- Area
- 1,750 sq ft
- Sector
- Residential
- Disciplines
- Architectural · Structural · Mechanical
Delivered
- Architectural design
- Structural design
- Mechanical design
- Permit drawings
Built to the client’s own plan, with one team answering for every discipline.
Start a project like this
A two-storey garden suite laid out to get the most usable space from the footprint, designed and permitted as a rentable unit.
- Location
- Richmond Hill
- Area
- 1,250 sq ft
- Sector
- Residential
- Disciplines
- Architectural · Structural
Delivered
- Layout planning
- Architectural drawings
- Structural design
- Permit application
Rental income and a higher property value.
Start a project like this
A dental office converted into a supermarket. Interior renovation, a new plumbing system and fire separations upgraded to the Ontario Fire Code.
- Location
- Kitchener
- Area
- Dental → grocery
- Sector
- Commercial
- Disciplines
- Architectural · Plumbing · Fire safety
Delivered
- Change-of-use permit
- Interior renovation drawings
- New plumbing design
- Upgraded fire separations
A dental office reopened as a supermarket, compliant with the Ontario Fire Code.
Start a project like this
A custom covered porch that turns the front of the house into usable outdoor space. Addition design and structural drawings for the permit.
- Location
- London
- Area
- 570 sq ft
- Sector
- Residential
- Disciplines
- Architectural · Structural
Delivered
- Addition design
- Structural drawings
- Permit application
More usable outdoor space and added home value.
Start a project like this
Site grading to manage drainage and prepare the land for a new driveway, drawn as a grading plan for the site alteration permit.
- Location
- Guelph
- Area
- 11,700 sq ft
- Sector
- Site
- Disciplines
- Site engineering
Delivered
- Grading plan
- Drainage design
- Driveway extension layout
- Site alteration permit
Drainage handled and the land ready for a new driveway.
Start a project like thisPhoto plates
Project Gallery: from the framing to the finished room.
Additions, basements, kitchens, new builds and commercial fit-outs. Drag a row to scrub through it, or open any photo full size.Tap any photo to see it full size.
21 platesResidential, commercial & new build
The drawing set
Drawing Samples: sheets from real permit sets.
Framing schedules, wall assemblies, dimensions and a city review stamp, as issued. Client title blocks are trimmed off to protect the people we drew them for.
- Sector
- Residential
- Discipline
- Architectural · Structural
- Location
- London, ON
- Scale
- —
Drawing set
Sheets in this set
Sheet title
Existing basement plan
The existing house recorded before any design: beams, joists and bearing walls.
Drawing no.
2 of 5
Service area
Where We Work: within 90 minutes of Richmond Hill.
From the office we cover the whole GTA, north to Barrie and Orillia, east to Peterborough and Cobourg, west to Kitchener and Brantford, and down through Niagara.
Our office
Service area
Completed project
Drive time, off-peak
Municipalities we serve
46 across 8 regions
York Region
- Richmond Hill (completed project)Office
- Vaughan (completed project)
- Markham (completed project)
- Aurora
- Newmarket
- King
- Whitchurch-Stouffville
- East Gwillimbury
- Georgina
Toronto & Peel
- Toronto (completed project)
- Mississauga
- Brampton
- Caledon
Halton
- Oakville
- Burlington
- Milton
- Halton Hills
Durham
- Pickering
- Ajax
- Whitby
- Oshawa
- Clarington
- Uxbridge
- Scugog
Simcoe & Dufferin
- Barrie (completed project)
- Innisfil
- Bradford
- New Tecumseth
- Orillia
- Wasaga Beach
- Collingwood
- Orangeville
Waterloo, Wellington & Brant
Hamilton, Niagara & Haldimand
- Hamilton
- Grimsby
- St. Catharines
- Niagara Falls
- Haldimand County (completed project)
Kawarthas & Northumberland
- Peterborough
- Kawartha Lakes
- Port Hope
- Cobourg
Past the 90-minute line
We've also completed projects in London and Strathroy. Farther out than that? Call (416) 990-9179 and ask.
Permits filed with municipalities including
Before you call
FAQ: legal basements, answered.
Anything we haven’t answered here, we’ll answer on a call. The first consultation is free.
(416) 990-9179Your part is a few decisions. Before the visit you send the ceiling height and photos and tell us whether the unit is for family or a tenant, which shapes the layout. After it you choose the exit route and whether the suite shares your furnace, approve the drawings before we file them, and pick the finishes during the build.
A building permit from your local building department, and a final inspection that passes. To pass, the suite needs the ceiling height the code sets, a fire separation from the main house, linked smoke alarms, carbon monoxide alarms where the code calls for them and a safe way out. We check each item at the first visit.
Not necessarily. The 2024 Building Code sets a minimum ceiling height for a secondary suite, and where a basement falls short, lowering the floor by underpinning is the usual answer. That is structural work, so our P.Eng designs it and it goes on the permit drawings with the rest of the unit.
Yes. Our engineer designs the opening so the wall still carries the house, plus the stairwell, guard and drainage around it, and we coordinate the build. A door is one way out of several, and we show you the other exit routes at the site visit.
It can. A shared furnace is one route, and separate heating is the other, which lets a tenant set their own temperature. Either way, our mechanical designer draws the heating for both units on the permit drawings.
The permit review comes first, then construction runs in stages around inspections. A basement that already has the height and a usable entrance is quicker than one that needs underpinning and a new door cut through the foundation. We give a schedule with the quote.
There is no single figure. The cost follows what your basement is missing against the code, which changes from house to house, so we price the job once the site visit has shown the gap. The first consultation is free, and the quote lists design and permit fees apart from construction.
Usually. The city treats it as a new application: drawings of what exists and what has to change, then inspections that sometimes mean opening walls. We prepare the drawings, answer the city and coordinate the corrective work.
Searched & answered
People Also Ask: what the GTA searches about legal basements.
Short answers to the legal basements questions people search most, and the broader topics they lead to.
Not covered here? Book a free consultationA legal basement is a basement apartment that meets the Building Code and the local zoning: a self-contained second unit with its own kitchen and bathroom. The code calls it a secondary suite, and Ontario’s planning rules call it an additional residential unit. Fine Engineering designs and permits these units across the GTA and coordinates the build.
At least 1.95 m, about 6 ft 5 in, under Ontario’s 2024 Building Code, with 1.85 m of clear height allowed under beams and ducts. The measurement runs from the finished floor to the finished ceiling, so new flooring and drywall count against it. Fine Engineering measures the height at the first site visit, before any layout is drawn.
It needs a safe way out, which is usually its own exterior door. In a house that has stood for five years or more, the 2024 Building Code’s renovation rules also accept an exit route through the other unit, as long as the suite gets an extra escape window that opens from inside without tools and the smoke alarms are linked. Fine Engineering works out which route suits the layout.
Yes. Once a house has a secondary suite, its smoke alarms must be interconnected, by wire or wirelessly, so one sets off the rest, and shared spaces need them too. A suite with a fuel-burning appliance, or one sharing a wall, floor or ceiling with such an appliance or a garage, also needs carbon monoxide alarms by its bedrooms. Fine Engineering marks every alarm on the permit set.
For many homeowners, yes. A legal second unit can earn rent and add property value, and because it was built under a permit, it avoids the trouble an unpermitted suite causes when the house is sold. The return depends on how much the basement needs, whether that is more headroom, a new exit or fire separation. Fine Engineering prices that work before any drawing starts.
A heat- or energy-recovery ventilator swaps stale indoor air for fresh outdoor air and passes heat between the two airstreams on the way. A new house, or a permit with HVAC work, usually needs a mechanical ventilation design, and Toronto Building asks for one with every HVAC permit application. An HRV or ERV is the usual way to meet it. Fine Engineering sizes them in its HVAC designs.
Good to know
Legal basement requirements in Ontario
Ontario’s 2024 Building Code makes 1.95 m the lowest ceiling a secondary suite may have, with 1.85 m of clear height allowed under beams and ducts. The suite also needs a fire separation from the rest of the house. Where the house has stood at least five years, the renovation rules accept 30 minutes, or 15 minutes for the floor between units if interconnected smoke alarms are in every unit and common area.
The alarms must be linked, by wire or wirelessly, so one sets off the rest, and shared spaces outside the units need them too. A suite needs carbon monoxide alarms when it has a fuel-burning appliance or flue, takes heated air from a fuel-burning forced-air furnace, or shares a wall, floor or ceiling with a garage or a room with such an appliance or flue. They go next to each bedroom, and on any storey of the suite with no bedroom.
Basement apartment exits and escape windows
Every basement unit needs a safe way out. In a house at least five years old, the code’s renovation rules accept three: an exterior door that serves only the suite, a shared exit behind a 30-minute fire separation, or a route through the other unit with an added escape window. The last two also need the house’s smoke alarms linked.
The escape window has to open from inside without tools, with a clear opening of at least 0.38 m² and no side narrower than 460 mm. Its sill can sit no higher than 900 mm above the floor and no more than 1,000 mm above or below the ground outside, and a window well needs 1,000 mm of clear space in front of the window. We measure each candidate window against those numbers.
Ontario’s three-unit rule for basement apartments
Since November 2022 the Planning Act has stopped a zoning by-law from prohibiting up to three units on a serviced urban residential lot: three in a detached house, semi or rowhouse, or two in the house and one in an ancillary building on the lot. A by-law also cannot set a minimum floor area for an additional unit, or ask for more than one parking space for it.
Under O. Reg. 299/19 the unit needs that one space for its occupant, and a tandem space counts. None is needed where the zoning by-law requires no parking for the main house, or requires that none be provided for the unit. Anyone may live in the unit, related to the household upstairs or not, and nobody living there has to own the lot. The unit is allowed however old the house is.
What drives the cost of a legal basement
The code list is the same for every basement, so the cost depends on how far a given basement is from meeting it. A ceiling already at code height, an exit that works without cutting a new door, drains deep enough for a second kitchen and bathroom, and an electrical panel with room to spare each keep the scope small.
Underpinning to gain height, a new entrance through the foundation, fire-rated assemblies under a finished ceiling, a larger window and well, or a service upgrade each add to it. The site visit shows which of these your basement needs.
Contact us
Entrance cut. Separation rated. Permit closed.
Send us the ceiling height and a few photos and we’ll tell you whether the basement can be made legal, on a free first call.
First consultation free(416) 990-9179