
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 · Aurora, York Region
Legal basement apartments in Aurora: separate entrances, fire separations, egress windows, the second kitchen and heating for two units. Under By-law 6660-24 the basement is an Integrated Unit registered with the Town, and we draw it for postwar houses west of Yonge and newer Bayview homes before filing with the Town of Aurora Building Division.

What’s included
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. In Aurora the package goes to the Town of Aurora Building Division, and it is drawn to that department’s checklist.
The package
Find your situation below. If it’s there, this is the service, and the card underneath is everything you get from our one office.
06 common situations
07
items in your package, all from one P.Eng and BCIN team.
Drawn & stamped in-house
How it runs
Four steps from a bare basement to a closed permit, with the inspections built into the schedule.
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.
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.
Entrance, framing, rough-ins, insulation and rated assemblies go in, inspected at each stage.
Kitchen, bathroom, flooring and doors, then the final inspection and the closed permit.
Case files
Open any file for the scope, the disciplines involved, what we delivered and what the owner came away with.

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.
Delivered
New living space on a lot the owners already had.
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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.
Delivered
An open layout where the load-bearing walls used to be.
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A code-compliant second unit with its own entrance, fire separations between the units, HVAC design and the full permit package.
Delivered
A legal second unit that brings in rent and adds property value.
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A new build taken from the client’s sketch to occupancy, with the architectural, structural and mechanical design done by one team.
Delivered
Built to the client’s own plan, with one team answering for every discipline.
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A two-storey garden suite laid out to get the most usable space from the footprint, designed and permitted as a rentable unit.
Delivered
Rental income and a higher property value.
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A dental office converted into a supermarket. Interior renovation, a new plumbing system and fire separations upgraded to the Ontario Fire Code.
Delivered
A dental office reopened as a supermarket, compliant with the Ontario Fire Code.
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A custom covered porch that turns the front of the house into usable outdoor space. Addition design and structural drawings for the permit.
Delivered
More usable outdoor space and added home value.
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Site grading to manage drainage and prepare the land for a new driveway, drawn as a grading plan for the site alteration permit.
Delivered
Drainage handled and the land ready for a new driveway.
Start a project like thisPhoto plates
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
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.
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
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.
46 across 8 regions
York Region
Toronto & Peel
Halton
Durham
Simcoe & Dufferin
Waterloo, Wellington & Brant
Hamilton, Niagara & Haldimand
Kawarthas & Northumberland
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
Anything we haven’t answered here, we’ll answer on a call. The first consultation is free.
(416) 990-9179A building permit for the unit, applied for with drawings at Aurora’s own building department rather than York Region. Aurora also has a site alteration by-law, and we check it whenever the stairwell for a new entrance changes the grade beside the house. We prepare and file the set and deal with the examiner’s comments.
Only where the lot is inside Lake Simcoe Region Conservation Authority (LSRCA) regulation, near a watercourse, a valley or a floodplain. Digging a stairwell down to the basement changes the grade there, and the LSRCA permit may be needed before Aurora issues the building permit. We check the regulation mapping before the entrance is drawn.
Under Aurora’s Registration By-law 6660-24 for Additional Residential Units, a parcel of residential land with a detached house, semi-detached house or rowhouse may have up to three units, including the house itself. That can be the house with one or two Integrated Units, located within or attached to the house, and no Ancillary Unit, or the house with no more than one Integrated Unit and no more than one Ancillary Unit. An Ancillary Unit is a detached unit in the rear or interior side yard, designed to be portable, also called a garden suite, laneway house or tiny home. Every ARU must be registered with the Town. For a basement unit in Aurora that means two steps: a building permit, and registering the unit, as the by-law requires.
Yes. We take on legal basements across Aurora, including Aurora Heights and Regency Acres, about half an hour from our Richmond Hill office. The first consultation is free, by phone or on site.
Three things to start: property address; basement ceiling height, measured floor to joist; and photos of the basement, the mechanical room and the outside wall where an entrance could go. Send those and we tell you what the Town of Aurora Building Division will ask for before we quote.
It could. Digging a stairwell cuts roots, and Bylaw 5850-16 treats that damage as injuring the tree. A heritage tree, or any tree on a lot inside the Northeast Old Aurora district, needs a permit before it is injured, so on those lots we put the entrance on a side clear of it where the plan allows. Elsewhere we count the work against the bylaw’s allowance of two larger trees a year.
Possibly, but we ask the Town before drawing it. Northeast Old Aurora is Aurora’s one Part V heritage conservation district, and a new door or a bigger basement window changes how the house looks from outside, so the designation may have a say. The unit itself still counts as an Integrated Unit under By-law 6660-24 and is registered like any other in town.
It can. Your lot’s zone in Zoning By-law 6000-17 sets the side and rear yards, and a sunken stairwell or a raised landing has to fit the rules for the yard it sits in. Many postwar houses west of Yonge went up long before those yards were set, so the space beside the house may be tighter than the zone expects, and we check it on your survey before the Town of Aurora Building Division sees the plan.
In CityView. The Town of Aurora Building Division shows the application’s status there from filing to issue, and each inspection the permit lists is requested through the same portal. Passing the last one closes the permit, and registering the unit under By-law 6660-24 is the other half of making it legal in Aurora, so we keep track of both for you.
One space, under Ontario’s O. Reg. 299/19, and a tandem spot behind yours counts, unless the zoning by-law asks for none. In Aurora we read the parking rules for your zone in By-law 6000-17 before the entrance and walkway are placed, because a walkway along the driveway can take the width a second car needs. The Town of Aurora Building Division checks zoning, parking included, before it issues the unit’s permit.
Searched & answered
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.
Usually because the heat reaching the room does not match the heat it loses. A room over a garage, or one with more glass and outside wall, loses heat faster, and a long or undersized duct delivers less air than the room needs. A room-by-room heat-loss calculation and a duct design show where the gap is. Fine Engineering does both for existing houses as well as new ones.
Good to know
In Aurora the reviewer is the Town of Aurora Building Division. Every Aurora lot sets its own terms: the spare capacity in the electrical panel and the size of the water service the two units will share decide how much work a basement unit needs.
We walk the site with the survey, usually within a day or two of the call, before anything is drawn, then file the legal basements package to the Town of Aurora Building Division’s own checklist.
Aurora’s housing runs to established postwar neighbourhoods west of Yonge seeing infill rebuilds, with newer subdivisions in the Bayview secondary plan areas to the east. On a lot being rebuilt, a basement unit is easiest planned before the foundation goes in, with ceiling height and drain depth set on the drawings. In an existing house in Town Park or Bayview Northeast, floor-to-joist height decides whether underpinning is needed.
A basement apartment is one Integrated Unit. Registration By-law 6660-24 allows a second, inside the house or attached to it, provided the lot then has no detached Ancillary Unit. If a third unit is on your list, choose early between that second Integrated Unit and a garden suite, because the basement entrance, the water service and the electrical panel are planned differently for each.
Aurora’s registration by-law covers semi-detached houses and rowhouses as well as detached ones, so a basement unit is open to them too. A rowhouse in the middle of a row has no side yard, so its entrance goes at the front or the rear, while a semi has one free side to work with. Wherever it goes, the stairwell has to meet the yard rules for your zone in By-law 6000-17, and we check those on the survey before laying out the unit.
Contact us
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