Leasing commercial space in Ottawa — an introduction

Ontario's residential tenancy system is protective by design: a mandatory lease form, a cap on most rent increases, a tribunal, and rules a landlord cannot contract out of. Commercial leasing has almost none of that. It is governed by your contract and, lightly, by the Commercial Tenancies Act.

Which means the lease is not paperwork confirming a deal you already made. The lease is the deal. Almost everything in it is negotiable — and anything you do not negotiate is negotiated in the landlord's favour by default.

One consequence deserves stating plainly. Ontario's guidance on commercial tenancies confirms the Act does not control rent increases, and that where rent goes unpaid a landlord may change the locks after 16 days, or seize and sell a tenant's property to recover arrears. There is no tribunal for this: disputes under $50,000 go to Small Claims Court, and larger ones to the Superior Court of Justice. Read the default and termination provisions at least as carefully as you read the rent.

A quoted rate is rarely what you pay. Most commercial space in Ottawa is offered on a net basis, where the quoted rent is the base and you additionally pay your share of property tax, building insurance, maintenance and common-area costs — usually called additional rent, TMI, or operating costs. A gross lease bundles more of that into one figure. The difference between the two is not a detail; it can be a large fraction of your real occupancy cost.

So the first question is never "how much per square foot?" It is "what is my total cost per month, including everything?" And then: how are those additional costs calculated, are they estimated and reconciled later, can I see the last two years of actuals, and is there a cap on how much they can rise?

Ask how the space is measured, too. Rentable area commonly exceeds the area you can actually use, because it includes a share of the building's common space. You will pay for the difference every month of the term.

• Permitted use, and zoning. The lease must permit what you intend to do, and the City's zoning must permit it at that address. Confirm both independently — a landlord's assurance is not a zoning approval.
• Term, renewal and what the renewal rent is. A renewal option at "market rent" with no mechanism to determine it is an argument scheduled for five years from now.
• Fit-out: who builds it, who pays, and who owns it at the end. Landlord allowances, free-rent periods and who is responsible for restoring the space are all negotiable, and all expensive to get wrong.
• Personal guarantees and indemnities. If your corporation signs but you guarantee it personally, the limited liability you set the corporation up for does not apply to this obligation. Ask for a cap or a time limit; the request is normal.
• Assignment and subletting. If your business grows, shrinks or sells, can you get out — and on what conditions? A lease you cannot transfer is a liability on your balance sheet when you try to sell the business.
• Repair and maintenance obligations. Establish precisely where your responsibility starts and stops — HVAC in particular is a common and costly ambiguity.
• Relocation and demolition clauses. Some leases let a landlord move you, or end the lease for redevelopment. Know whether yours does before you spend on a fit-out.

Ontario — renting commercial property · Commercial Tenancies Act (Ontario) · City of Ottawa — maps and zoning

Links verified July 24, 2026.

A fuller commercial series is planned rather than promised. If you are a residential tenant or landlord, the protections above genuinely do apply to you — start with renting and leasing in Ottawa instead.