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Legal Basement Apartment London | Cost Per Sq Ft
SUITE.
Legal basement apartments · London, Ontario

Legal Basement Apartments
in London

London is the rare Ontario market where the suite math is easy to check: two big campuses, a teaching-hospital network, and house prices still well below the GTA. IntraBuild converts London basements into registered second suites end to end — zoning check, drawings, building permit, fire separation, egress, kitchen, bath, inspections and the City's paperwork. The whole job runs through one crew of licensed trades, and the cost is a single written number computed from the suite's square footage.

Permit & licence paperwork
Rated fire & sound separation
Priced by the square foot
Bright legal basement apartment suite in a London Ontario home finished by IntraBuild
48h
From first call to written number
2 units
Two legal dwellings, one house
1 crew
Zoning check through licensing
$0
Added for the drive to London
48hQuote turnaround
InsuredFully insured crew

A legal basement apartment in London is a working asset — a registered second suite with its own kitchen, three-piece bath and independent services, earning against a tenant pool that renews itself every September. IntraBuild's scope opens with the zoning check and closes with the City of London's paperwork; between them sit the drawings and permit, then licensed trades building the fire and sound separation, egress windows and the suite's own systems, then the final inspections. The pricing is plain arithmetic — square feet of suite area times a stated rate — and every figure starts from a measured basement, never a phone guess.

01
— what London requires

Fire-rated, exit-safe, licensed.

compliance before cash flow

Rated separation & interconnected alarms

Between suite and house sits a rated fire separation — 45 minutes is the standard spec, walls and ceiling both — and the smoke and carbon monoxide alarms are interconnected across the two units. In a city full of informal student rentals, this is what separates an asset from a liability.

Egress & headroom

Two numbers gate every conversion: bedroom egress — a window with a code-sized opening, or a second exit — and ceiling height. Century homes in Old North and Old South often measure short, which is why the first visit involves a tape measure, not a contract.

A complete small dwelling

Kitchen, three-piece bath, ventilation, optional laundry — a suite only counts as a dwelling when it runs as one, on plumbing and wiring independent of the house upstairs. That independence is what lets you advertise it openly, insure it and count its rent with a lender.

Permits, inspections & licence

A building permit from the City of London, staged inspections — and, because London licenses smaller rental buildings, a rental unit licence once a tenant moves in. We manage the file so nothing lapses.

45-min fire separation — suite to house, both directions Interconnected smoke/CO alarms — one sounds, both hear Egress window or second exit — every sleeping room Sound separation — tenancies that actually last Registration — permit, inspections, London's rental licence
02
— what a London suite earns

Yield, family room, resale.

the campus-town balance sheet

Rent with real demand behind it

A well-finished registered one-bedroom in London typically rents somewhat below the core-GTA $2,300–2,600 range — but the house beneath it cost far less too, so the yield often reads better here than in Toronto. Western, Fanshawe and the hospitals keep the tenant pool deep year-round.

Room for the family ledger

Parents with their own kitchen and door, or a student kid at home without actually living with you — an in-law suite is the least expensive extra home a London family can put on its books.

A mortgage that carries itself

London is still a market where first-time buyers can get in — and a legal suite turns a stretch into a plan: from the month the licence lands, the rent line starts offsetting the mortgage line.

Resale that survives scrutiny

A registered two-unit house is a different listing than a house with "a basement apartment" — the permit and inspection record proves the suite was built properly — and London's investor buyers screen for that.

03
— legal suite cost in London

Scope times footage, in writing.

rate × square feet, that's it

Three inputs decide the number: the basement's state today (finished or bare), the scope you buy (compliance only, or the full build), and whether a new entrance gets cut. As a working guide, budget $90–190 per square foot of suite area against a typical minimum project around $60,000, before HST. In London, with trades and materials pricing below the core GTA, most conversions land toward the lower half of that range.

retrofit

Retrofit

Finished space, brought to code and licence
$90–115 /sqft
  • Rated assemblies for the fire separation
  • Egress corrected, alarms interconnected
  • Wiring upgraded & put through inspection
  • Drawings, permit & registration filed
Minimum project$60,000
Choose Retrofit
most chosen

Full Suite

Bare London basement to rentable suite
$115–150 /sqft
  • The Retrofit scope, and on top of it:
  • Complete build-out, studs to final coat
  • Kitchen plus a three-piece bathroom
  • Sound-insulated floor between the units
Minimum project$60,000
Choose Full Suite
entrance

Suite + Entrance

Its own door — and the top of the rent range
$150–190 /sqft
  • The Full Suite scope, and on top of it:
  • Its own entrance, side or rear
  • Bigger windows set in proper wells
  • Tenant-grade premium finishes
Minimum project$60,000
Choose Suite + Entrance
— London suite estimate

Check the math before we visit.

Projected turnkey range
$92,000 – $120,000
Treat this as the London planning envelope, before HST. Where you land inside it depends on layout, entrance work and what the existing basement reveals — the free written quote turns the envelope into a line item.
Typical London projects, turnkey
Compliance retrofit of a finished basement (≈700 sq ft)$63,000–80,000
Full suite from an unfinished basement (≈800 sq ft)$92,000–120,000
Full suite with its own entrance (≈1,000 sq ft)$150,000–190,000
Lowering a century-home basement / underpinningseparate scope
    What moves a London number
  • Scope — retrofit, full build or entrance cut is the biggest lever.
  • The house's age — century wiring, plumbing and framing add correction work.
  • Kitchen & bath — fixture level and plumbing runs swing the total.
  • Concrete & egress — cutting for doors and larger windows adds cost.

One rate, one ledger line: drawings and permit filings, the rated fire and sound separation, every licensed trade, kitchen, bath and finish work, each staged inspection and the licence paperwork that closes the file — nothing extra for the drive down the 401. Budget upward from the $60,000 minimum. Everything on this page is a planning figure before HST; the number worth taking to your lender is the written quote that follows the measurement.

04
— the suites we actually build in London

Old North to Summerside.

four London realities

Two housing stocks, two playbooks

Old North and Old South run on century homes — brick above, stone or rubble foundations below, ceilings that measure short and wiring from another era. Those convert as careful retrofits, occasionally with underpinning. Byron, Hyde Park, Summerside and Stoney Creek run on poured-concrete basements with full height: clean, predictable full-suite builds.

City Hall, in practice

Additional residential units are permitted across most of London's residential zoning, with the building permit running through the City of London's building division. Because the city licenses small rental buildings, a rented suite also carries a residential rental unit licence — we prepare the file so both clear.

A tenant pool that renews itself

Western and Fanshawe bring tens of thousands of students on a September cycle, and the LHSC hospitals add staff who want quiet twelve-month leases. Suites around Masonville, Old North and the Fanshawe corridor rarely sit empty for long.

London clay and old stone

Much of the city sits on clay-heavy soil, and the older foundations were never waterproofed. We check grading, drainage and the foundation walls before any finish material comes near them — a dry suite is the only kind worth licensing.

05
— the compliance file behind every suite

The paper trail, kept clean.

provable, not just built

Two codes, one spec sheet

Ontario's Building Code and Fire Code between them dictate the separation ratings, the alarm interconnection, the exit sizing and the headroom. Our London drawings quote both documents from the first line — which is why the inspector's visit usually reads as confirmation, not correction.

Zoning, checked before drawings

Where a second unit may sit, how parking must work, where a door can face — London's zoning by-law rules on all of it, and a Wortley Village lot gets a different ruling than a Summerside one. That ruling is the first thing we obtain, and it's free: the by-law question gets answered before a dollar goes into design.

Wiring under ESA eyes

Our electricians hold the licences; the Electrical Safety Authority checks their work. Panel upgrades, kitchen circuits, pot lights and the alarm interconnection are all inspected while still visible — and in a century home, the legacy wiring gets corrected on the way through, never buried.

The closing paperwork, done

The job doesn't end at the last inspection — it ends at City Hall. We carry London's file the final mile, rental licence included where a tenant is coming, and leave you holding a unit whose legality can be looked up rather than taken on faith by a lender, an insurer or the next buyer.

06
— which package fits which basement

Three basements, three answers.

match scope to starting point
Retrofit · compliance
Legalize what's already finished
London is full of basements finished informally over the decades — often for students. This scope legalizes them: rated separations and interconnected alarms go in, egress is brought up to spec, the ESA reviews the wiring, and the permit and licence files run to completion under our name.
Full Suite · most chosen
Blank basement, complete apartment
In Byron, Summerside or Hyde Park the basement is usually a blank slate — the cheapest kind to convert per foot. One crew carries it from bare concrete to first lease: framed and insulated, boarded and painted, a kitchen and three-piece bath plumbed in, sound insulation overhead, floors and doors to close it out.
Suite + Entrance · walkout
Its own front door
The foundation gets cut for a private side or rear door, the windows grow into proper wells, and the finish level targets the top of the local rent table. Hospital staff and grad students pay the premium; the premium repays the cut.
07
— working with IntraBuild in London

One contract, every trade.

one number to call

Drawings and filings, in-house

Design happens at our desk and the City of London filing goes in under our name — one agreement covers drafting, permits and construction, so there are no third parties for you to referee.

Every trade, one schedule

One project lead owns the calendar, and every licensed trade the suite needs reports into it — when a question comes up, there is exactly one person who owes you the answer.

Built to pass, first time

A failed inspection is a month of rent deferred, so we sequence for passing: every stage arrives at its inspection ready, before anything gets closed in over it.

Clean site, covered risk

Insurance certificates precede the first cut, dust stays behind sealed poly, and each workday ends with a cleanup — upstairs, the household's term-time routine carries on undisturbed.

08
— from idea to licensed suite

Six stages, in order.

an inspection between each
1

Zoning first, then drawings

Desk work opens the file: does the address zone for a second unit? Then the tape measure — headroom, egress options, moisture — and only after both answers does a code-clean layout get drawn.

2

Building permit

We submit to the City of London and answer the reviewers until the permit issues. Until that day, no tools come out of the truck.

3

Structure & services

Framing sets the rooms, and while the cavities are still open the suite receives services of its own — wiring, plumbing and ductwork independent of the house above.

4

Separation & alarms

The fire separation gets built between the two dwellings, the ceiling takes its sound insulation, and the smoke and CO alarms are interconnected across both homes — with an inspector's signature before a sheet of drywall covers it.

5

Kitchen, bath, finish line

This is where the economics arrive: kitchen and three-piece bath installed, then floors, doors, trim and paint. Whether the unit leases by Labour Day is largely decided here.

6

Final inspections & licence

The last inspections clear, the City's file — rental licence included where it applies — is completed, and the suite begins its working life on the right side of the ledger.

Six stages, each gated by an inspection nobody is allowed to waive — those gates are precisely what a licence certifies. The quote arrives with an honest calendar attached, and if the goal is a September lease we'll name the month the file has to open.

09
— London suite questions

The London question set.

what London owners ask first

What does a legal basement apartment cost in London?

Across our service area, turnkey conversions run $90–190 per square foot of suite area, with a typical minimum around $60,000, before HST. London projects tend to land in the lower half of that span. The range is for planning; the figure worth planning on arrives in writing, after we've measured.

Who issues the permit — and what does London add on top?

The building permit comes from the City of London's building division, with staged inspections through the build. London also licenses smaller rental buildings, so a suite you rent out carries a residential rental unit licence as well. We handle both files end to end.

Can I rent legally to Western or Fanshawe students?

Yes — a permitted, inspected and licensed suite can be advertised and rented openly, students included. If anything, fire separation and proper egress matter more with a rotating student tenancy, not less. Suites listed in late summer lease fastest and at the best rates.

My century home has low ceilings — is a suite still possible?

Often, yes. Ceiling height has a code minimum and the tape measure settles the question on day one — plenty of Old North and Old South basements pass once the mechanicals are routed with care. When the floor truly must drop, underpinning or bench footing enters the picture: structural work carrying its own separate price.

Is a separate entrance required?

The code doesn't force one in every case — with the fire separation built correctly, a shared entrance can pass. The market votes differently: a private door leases faster and at better rates, which is why most London landlords order the cut. Suite + Entrance prices it as one package, concrete and all.

How long does the whole thing take?

Site time is only half the answer — weeks for a retrofit, months for a full build or an entrance cut. The other half is the City's permit queue, which we work but don't control. Counting backwards from a September 1 lease, the project belongs on paper by winter.

What rent should I model for a London suite?

Model conservatively: a well-finished registered one-bedroom in London typically rents somewhat below the core-GTA $2,300–2,600 range, with walkouts and sharper finishes at the top of the local market. It's an input for the spreadsheet, not a guarantee — street, finish level and the walk to Western, Fanshawe or the hospitals decide the cell's real value.

My basement is already finished — can you convert it?

Yes — that's the Retrofit lane. What's built stays; what's missing goes in: the fire separation, the interconnected alarms, compliant egress, electrical brought current. From there the suite walks through inspection to its licence — expect the odd opening cut in a finished wall where the inspector needs to see behind it. A rec room for your own family with no tenant is a different product entirely: our basement renovation service, on its own pricing.

— more service areas

Legal basement apartments nearby.

A legal basement apartment isn't limited to London — IntraBuild works right across the GTA and Southern Ontario, all on one written per-square-foot price with no separate travel fee.

— ready when you are

Put a number on your basement.

Three facts open the file: approximate square footage, finished or bare, entrance wanted or not. We take it from there — zoning verified, basement measured, and the whole run from drawings to licence returned as a single written figure. Costs nothing, obliges nothing — and in this market the arithmetic usually argues our case for us.

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