The right, and its limits
Section 36.1(1): a tenant "may install and use a window or portable air conditioner in a rental unit for which the landlord does not supply air conditioning", unless prohibited under subsection (2), and subject to the conditions in subsection (3).
This is a right, not a request. A tenant telling you they are putting in a window unit is complying with the Act. Treating that notice as an application to be approved or refused misreads the section.
Subsection (2) permits a landlord to prohibit installation "in the prescribed circumstances" — prescribed meaning set out in regulation, not decided by the landlord. A blanket no in the lease is not one of them.
The five conditions on the tenant
Written notice to the landlord before installing. Not after, and not verbally.
Where a rent increase under subsection (5) may apply, the notice must include what the tenant knows about the unit's energy efficiency and their anticipated usage.
The air conditioner, its installation and its operation must not damage the rental unit or the residential complex.
It must be installed safely and securely — the condition that matters most for a unit hanging over a sidewalk.
Installation must not be prohibited by "any applicable municipal property standards by-law or other applicable law", and it must be installed and maintained in accordance with those laws. Some municipalities restrict window projections; that restriction survives section 36.1.
You may inspect, and the Act says how
Section 36.1(4) is unusually helpful: "a reasonable inspection by a landlord for the purpose of determining compliance with paragraph 3, 4 or 5 of subsection (3) is a circumstance for which a landlord may enter a rental unit under paragraph 4 of subsection 27 (1)".
In other words, checking that the installation is safe and lawful is a recognised reason for entry — which means it is a section 27 entry, needing 24 hours' written notice stating the reason, the day, and a time between 8 a.m. and 8 p.m.
It does not create a right to walk in. It creates a valid reason to serve the notice.
The electricity increase, and its cap
Section 36.1(5) applies only where the landlord is obligated under the tenancy agreement to supply electricity. Where the tenant holds the hydro account, there is nothing to recover and no increase.
Subsection (6) removes the increase entirely if the tenancy agreement expressly says the tenant may install a window or portable air conditioner without any rent increase.
Subsection (7) caps it: the increase "shall not exceed the actual cost to the landlord of the electricity supplied for the operation of the air conditioner", or a reasonable estimate where actual cost cannot be established. This is cost recovery, not a rent rise — do not treat it as an opportunity to reprice.
Keep the arithmetic. An increase you can show is a calculation survives; one that looks like a round number chosen for convenience does not.
What this is not
Air conditioning is not a vital service. Section 21's protections cover heat, electricity, fuel, gas and water — cooling is absent from that list.
But if you do supply air conditioning under the tenancy agreement, withdrawing it is a reduction in services under section 125, and extreme heat in a unit can still raise section 20 habitability questions on its own facts.
The practical posture is simple: log the tenant's written notice, inspect for safety on proper notice if you have reason to, and calculate any electricity increase honestly.