- Every commercial building has ongoing costs: property taxes, building insurance, utilities for common areas, snow removal, parking-lot maintenance, and more.
- Under a gross lease, the tenant pays one all-in monthly rent.
- A net lease separates base rent from the building's operating costs.
Signing your first commercial lease is a significant moment for any Ontario small business owner — and one of the most confusing parts is figuring out exactly what you will be paying each month. The terms gross lease and net lease (and the dreaded triple-net) describe how operating costs are divided between a landlord and a tenant. Misunderstanding the difference between a gross vs. net commercial lease in Ontario can mean thousands of dollars in unexpected bills after you move in.
This guide breaks down each structure in plain language so you know what you are agreeing to before you sign.
The Basic Question: Who Pays the Building's Running Costs?
Every commercial building has ongoing costs: property taxes, building insurance, utilities for common areas, snow removal, parking-lot maintenance, and more. The lease structure determines whether the landlord bundles those costs into a single rent figure, or whether the tenant pays them — on top of base rent — as they arise.
Gross Lease (or Full-Service Lease)
Under a gross lease, the tenant pays one all-in monthly rent. The landlord uses that payment to cover property taxes, insurance, and most maintenance costs. The tenant generally pays for its own in-suite utilities and any cleaning services inside the unit.
Who typically uses it: Office buildings, older retail plazas, and professional-services spaces sometimes offer gross leases. They are simpler to budget because the tenant's monthly outlay is predictable.
Watch for: Landlords often include an expense stop — a cap on the building costs they will absorb. If costs rise above that stop, the tenant pays the overage. Read the definition carefully.
Net Lease
A net lease separates base rent from the building's operating costs. The tenant pays a lower base rent plus a proportionate share of one or more of the following:
- Property taxes (one "net")
- Building insurance (two "nets")
- Common-area maintenance (CAM) / operating expenses (three "nets")
Single Net, Double Net, and Triple Net
| Type | Tenant Pays |
|---|---|
| Net (N) | Base rent + property taxes |
| Net-Net (NN) | Base rent + taxes + insurance |
| Triple-Net (NNN) | Base rent + taxes + insurance + CAM/operating costs |
Triple-net (NNN) is the most common structure in Canadian commercial real estate, particularly for standalone retail buildings, industrial units, and anchor tenancies. The tenant's total monthly payment can swing significantly because operating costs are passed through directly.
What Is "Additional Rent"?
You will often see a lease refer to Additional Rent, TMI, or CAM:
- TMI — Taxes, Maintenance, and Insurance. The three main buckets of operating expenses passed to tenants under a net lease.
- CAM — Common Area Maintenance. The costs of maintaining shared areas: hallways, parking lots, lobbies, HVAC systems, landscaping, and property management fees.
- Additional Rent — The lease's umbrella term for everything the tenant owes beyond base rent. It usually includes TMI plus any other landlord-designated cost items.
Landlords typically estimate Additional Rent at the start of each lease year and collect it monthly. At year-end they reconcile — if actual costs were higher, the tenant pays a top-up; if lower, the tenant receives a credit. Always ask for the prior two years of operating cost statements before signing so you know what reconciliation looks like in practice.
How to Calculate Your True Monthly Cost
Under a net lease, your real cost is:
Base Rent per sq ft × leased sq ft + your proportionate share of operating costs
Your proportionate share (sometimes called your "Rentable Area Ratio") equals your leased area divided by the total rentable area of the building or complex. If you lease 1,000 sq ft in a 20,000 sq ft plaza, your share is 5% of the building's total TMI.
Gross vs. Net: A Side-by-Side Summary
| Factor | Gross Lease | Triple-Net Lease |
|---|---|---|
| Budgeting | Simple — one number | Variable — watch reconciliations |
| Landlord cost risk | Landlord absorbs cost increases | Tenant absorbs cost increases |
| Base rent | Higher (costs baked in) | Lower (costs added on top) |
| Common in Ontario? | Some office/professional | Very common retail & industrial |
| Negotiating focus | Expense stop definition | CAP on CAM increases; what's excluded |
Key Negotiating Points for Ontario Tenants
- CAM cap: Negotiate an annual cap on increases to controllable CAM expenses (management fees, landscaping) so you are not surprised by double-digit percentage jumps.
- Exclusions: Push to exclude capital expenditures (roof replacement, structural repairs) from the CAM pool. Those are long-life improvements that should not be your annual expense.
- Audit rights: Ask for the right to audit the landlord's operating-cost statements within 12–18 months of receiving the annual reconciliation.
- Gross-up: If the building is less than fully occupied, landlords often "gross up" variable expenses to 95–100% occupancy. Understand this clause before agreeing to it.
Frequently asked questions
Is there a law in Ontario that defines what can go into Additional Rent?
Ontario's Commercial Tenancies Act governs commercial leases but does not prescribe what costs must or cannot be included in Additional Rent. The definition is almost entirely determined by the lease itself. This is why careful review before signing matters so much.
Can I negotiate a gross lease on a space that is offered as triple-net?
Yes — lease structures are negotiable. A tenant with strong credit, a long term, and a desirable space profile often has leverage to push for gross-rent treatment or at least a fixed Additional Rent amount for the first few years.
What happens if the landlord's operating costs go down? Do I get money back?
Under a standard triple-net lease with annual reconciliation, if actual costs come in below the estimated amounts you paid monthly, you receive a credit (or refund) at year-end. Confirm this mechanism exists in your lease.
Our lease says "modified gross" — what does that mean?
A modified gross lease sits between pure gross and pure net: some costs are baked into the rent (e.g., taxes) while others (e.g., utilities, janitorial) are paid separately by the tenant. Read the specific definitions — the label alone tells you nothing.
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