Most repair disputes trace back to a line that was never drawn clearly at move-in. Getting the landlord's-work-versus-tenant's-work split into the lease itself, in specific terms, is cheaper than litigating it later.
Key takeaways
Almost every repair dispute in a commercial lease traces back to the same root cause: nobody wrote down, specifically enough, whose job a given system was. “Landlord's work” and “tenant's work” sound like they should be self-explanatory, and in the easy cases — the tenant's own interior paint, the landlord's own roof structure — they are. The expensive disputes live in between.
How a space is delivered at the start of the lease sets the baseline for everything that follows. Ontario commercial leases generally use one of three structures: “as-is” — tenant accepts the space in current condition; a defined Landlord's work schedule — the landlord completes specified improvements before handover; or a “blank canvas” — the space is cleared entirely and the tenant builds from scratch. Which one applies changes the entire repair-responsibility conversation that follows, because it sets what condition the tenant is deemed to have accepted at the outset.
The default allocation runs along a structural/interior line. Landlord responsibility typically covers “foundation, load-bearing walls, exterior walls, roof structure (not roof membrane), columns” and systems serving the building broadly or its common areas. Tenant responsibility typically covers “flooring, interior walls, ceiling tiles, interior doors”, the tenant's own mechanical and electrical systems within the unit, and damage caused by the tenant or its guests. That split is intuitive right up until a specific system doesn't map cleanly onto either category, which is where the real negotiating happens.
HVAC is, by a wide margin, the area where the general principle breaks down most often. The underlying logic is sound — a unit serving only the tenant's own space should logically be the tenant's responsibility, while a unit serving multiple tenants should fall to the landlord — but in practice, many leases push all HVAC maintenance and repair to the tenant, including the obligation to enter a mandatory preventive maintenance contract, regardless of which category the unit technically falls into. That matters because the dollar exposure is real: “a rooftop HVAC unit replacement can cost tens of thousands of dollars.” A tenant taking on full HVAC responsibility without negotiating some protection — a capital-expenditure exclusion, a warranty carried over from the landlord's own installation, or a cap tied to the unit's age — is accepting an open-ended exposure most tenants don't fully register at lease signing.
An “as-is” delivery shifts real risk onto the tenant, because the tenant is accepting the space's condition without the landlord warranting anything about it. The practical safeguard is straightforward: “have the HVAC, plumbing, electrical, and roof inspected by professionals before possession.” A pre-possession inspection report, kept on file by both sides, is also the cleanest evidence available later if a dispute arises over whether a defect existed at handover or developed afterward under the tenant's watch.
It's worth keeping two similarly named mechanisms distinct. Landlord's Work is the landlord building a defined scope to a lease schedule and handing over a finished space. A tenant improvement allowance is the landlord contributing money toward a build-out the tenant runs itself. A lease can use either, both for different scope items, or neither — but conflating the two in negotiation is a common source of the “I thought that was included” dispute that surfaces months later, once the build-out is already underway and change orders start getting expensive. The same boundary question matters when the tenant's own build-out later interacts with the fixturing period it's expected to finish inside.
A retail tenant accepts a unit “as-is” after a pre-possession inspection notes the rooftop HVAC unit as functional but nearing the end of its typical service life. The lease pushes HVAC maintenance and repair entirely to the tenant, with no capital-expenditure carve-out negotiated at signing. Fourteen months in, the unit fails and needs full replacement rather than repair. Because the lease drew no line between routine maintenance and capital replacement, and the pre-possession inspection report documented the unit's condition as merely “functional” rather than warranting a specific remaining lifespan, the tenant is responsible for the replacement cost in full. Negotiating even a partial capital-cost split for major system failures within the first two years — before signing, not after the unit failed — is the point at which this exposure was actually manageable.
The membrane specifically, as distinct from the structural roof, is one of the areas that “varies” by lease even though roof structure generally falls to the landlord. Confirm which side of that specific split a given lease lands on rather than assuming the general structural rule automatically extends to the membrane.
Yes — common area maintenance is a landlord responsibility recovered through CAM charges from all tenants proportionately, which is a different mechanism entirely from the direct repair obligations inside an individual tenant's own demised premises.
Often, yes, especially at initial lease negotiation rather than after signing — a capital-expenditure exclusion, a landlord-carried warranty for a defined period, or a shared-cost structure above a certain repair threshold are all common negotiated alternatives to full tenant responsibility.
Only for what the tenant actually builds and to the extent the lease says so — a blank-canvas delivery shifts build-out responsibility to the tenant, but it doesn't automatically override the lease's separate ongoing repair-and-maintenance allocation once the space is built. The two are related but distinct questions, and a lease should address both rather than leaving the second to be inferred from the first.
Because there mostly isn’t a default rule to fall back on. Our sister firm’s guidance explains that “Ontario’s Commercial Tenancies Act contains limited repair provisions and does not set out a comprehensive framework for who maintains what,” and that while courts fill some of the gap with common-law principles — including an implied obligation on the landlord to deliver premises fit for their intended use at the outset — those implied terms are almost always overridden once the lease sets out its own express language. The lease is the definitive answer precisely because the statute was never meant to be.
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