A commercial lease can shape a business for years. The location may be right, the space may look ideal, and the rent may seem manageable at first. But the real risk is often in the details of the lease.

For business owners leasing office, retail, warehouse, industrial, or other commercial space, the lease is not just a document that gives access to the premises. It can affect monthly costs, repair responsibilities, renewal options, exit rights, personal liability, and the ability to sell or move the business later.

Many lease problems do not start as disputes. They start as assumptions. A tenant assumes rent will stay predictable. A landlord assumes the tenant is responsible for repairs. A business owner assumes they can renew, assign, sublet, or walk away if the business changes. The lease may say something very different.

A careful review before signing can help business owners understand the long-term commitment and avoid expensive surprises.

Start with the full cost of the lease

The first number most business owners look at is base rent. That matters, but it is rarely the whole cost.

Commercial leases may include additional rent, common area maintenance charges, property taxes, building insurance, utilities, HVAC costs, waste removal, signage fees, parking, administrative fees, and other operating expenses. In some leases, these costs can change over time and may be difficult to predict.

A lease that appears affordable based on base rent alone may become much more expensive once all additional charges are included.

Before signing, business owners should understand whether the lease is gross, net, double net, triple net, or another structure. They should also ask how additional rent is calculated, whether estimates are reconciled annually, whether the landlord must provide supporting statements, and whether there are caps on increases.

Rent increases and escalation clauses

Rent increases should be reviewed carefully because they affect the business long-term. Some leases set fixed increases each year. Others tie increases to a formula, market rent, operating costs, or renewal negotiations.

A small increase may seem manageable in year one, but over a five or ten-year term, escalation clauses can significantly affect cash flow.

Business owners should look for:

• scheduled rent increases;
• percentage increases;
• consumer price index or inflation-based increases;
• market rent adjustments;
• additional rent increases;
• landlord administration fees;
• increases that apply during renewal terms.

Rent clauses should be clear enough to calculate. If a business owner cannot understand how rent will increase, that is a reason to ask questions before signing.

Renewal rights should not be assumed

Many tenants assume they can stay if the business is doing well. That is not always true. A lease may end at the expiry date unless the tenant has a valid renewal option and exercises it properly. Renewal rights often have strict notice requirements. If the tenant misses the deadline, the landlord may not have to extend the lease.

A renewal clause should answer several questions:

• How many renewal terms are available?
• How long is each renewal term?
• When must notice be given?
• How will rent be determined during the renewal term?
• Can the landlord refuse renewal if the tenant has been in default?
• Are all lease terms carried forward, or can some be renegotiated?

For retail businesses, restaurants, clinics, offices, and other location-dependent companies, renewal rights can be critical. Losing the space may mean losing customer traffic, goodwill, build-out investment, signage value, and local recognition.

Repair and maintenance obligations

Repair clauses can create major unexpected costs. A tenant may assume the landlord is responsible for the building because the landlord owns it. In commercial leases, that assumption can be risky. Depending on the lease, the tenant may be responsible for interior repairs, HVAC maintenance, plumbing, electrical systems, glass, doors, fixtures, or even certain structural-related costs passed through as operating expenses.

The lease should clearly define who is responsible for:

• structural repairs;
• roof, foundation, and exterior walls;
• HVAC systems;
• plumbing and electrical systems;
• windows, doors, and glass;
• interior repairs;
• snow removal and landscaping;
• compliance with building code, accessibility, fire, or municipal requirements;
• repairs caused by prior tenants or pre-existing conditions.

Business owners should also consider whether the space is being leased “as is.” If so, they may be accepting the premises in its current condition, including problems that are discovered later.

A pre-signing inspection can help, but the lease wording still matters.

Personal guarantees and individual risk

Many business owners lease space through a corporation. They may assume the corporation protects their personal assets if the business cannot continue. A personal guarantee can change that risk.

A personal guarantee may allow the landlord to pursue the individual business owner personally if the tenant corporation defaults. That can include unpaid rent, additional rent, repair costs, damages, legal fees, and other lease obligations depending on how the guarantee is drafted.

Not every guarantee is the same. Some are unlimited. Some are limited by time, amount, or type of obligation. Some continue through renewals, assignments, or extensions. Some are written as indemnities, which may create broader exposure.

Before signing a guarantee, business owners should understand:

• who is personally liable;
• whether the guarantee is limited or unlimited;
• whether liability reduces over time;
• whether it applies to renewal terms;
• whether it survives an assignment;
• whether the landlord can pursue the guarantor before pursuing the corporation;
• whether the guarantee can be negotiated.

A personal guarantee is often one of the most important clauses in the lease. It should not be treated as a formality.

Assignment and subletting rights

Businesses change. A company may outgrow the space, downsize, sell the business, relocate, merge, or shift operations. Assignment and subletting rights determine whether the tenant has flexibility if the space no longer works.

An assignment usually transfers the lease to a new tenant. A sublease allows another party to occupy some or all of the space while the original tenant remains under the lease.

Most commercial leases require landlord consent before assignment or subletting. The key issue is how that consent works. Some leases say the landlord cannot unreasonably withhold consent. Others give the landlord broad discretion or include conditions that make transfer difficult.

Business owners should review:

• whether assignment or subletting is allowed;
• whether landlord consent is required;
• whether consent can be unreasonably withheld;
• what information the landlord can request;
• whether fees apply;
• whether the original tenant remains liable after assignment;
• whether the landlord can terminate the lease instead of approving the transfer;
• whether a sale of shares or change of control counts as an assignment.

This is especially important for business owners who may sell the business. A buyer may want the location, but the lease may restrict transfer.

Permitted use and exclusivity

The permitted use clause controls what the tenant can do in the premises. If the wording is too narrow, it can limit the business later.

For example, a retail tenant may begin with one product line and later want to add services, online order pickup, classes, events, or complementary products. A clinic may want to add new practitioners. A warehouse tenant may want to expand into light manufacturing or distribution.

If the permitted use clause does not allow the change, the tenant may need the landlord’s consent.

Business owners should also consider exclusivity. In some retail plazas or commercial properties, a tenant may want protection against the landlord leasing nearby space to a direct competitor. Without an exclusivity clause, that protection may not exist.

The use clause should support the business as it operates today and as it may reasonably evolve.

Termination, default, relocation, and demolition clauses

A lease should be reviewed for what happens when things go wrong or when the landlord wants flexibility.

Default clauses set out what happens if rent is late, insurance is not maintained, repairs are not completed, or another lease obligation is breached. These clauses may give the landlord remedies, including termination, re-entry, legal costs, or acceleration of rent.

Other clauses may allow the landlord to relocate the tenant within the property or terminate the lease if the building is being demolished, redeveloped, or substantially altered.

Business owners should review:

• what counts as default;
• whether the tenant receives notice and time to fix the issue;
• what remedies the landlord has;
• whether the landlord can recover legal costs;
• whether rent can be accelerated;
• whether the landlord can relocate the tenant;
• whether demolition or redevelopment can end the lease;
• whether the tenant has any termination rights.

A business that spends significant money on leasehold improvements should be especially careful. If the lease can be terminated early under broad landlord rights, the tenant may not have enough time to recover that investment.

Leasehold improvements and build-out costs

Many commercial tenants need to renovate before opening. That may include flooring, lighting, walls, signage, counters, equipment, accessibility upgrades, plumbing, ventilation, or specialized infrastructure.

The lease should explain who pays for the work, who owns the improvements, whether landlord approval is required, who obtains permits, whether contractors must be approved, and whether the tenant must remove improvements at the end of the lease.

A tenant improvement allowance can help, but the conditions matter. The landlord may only pay after work is complete, after lien periods expire, or after specific documents are provided.

Business owners should also confirm whether the lease gives enough fixturing time before rent starts. Paying full rent while waiting for permits, contractors, inspections, or utility setup can create pressure before the business opens.

Hidden costs and operating expenses

Hidden costs are not always hidden because someone is trying to be unfair. They are often hidden because business owners focus on the main rent number and do not review how additional rent works.

Common hidden or underestimated costs include:

• property tax increases;
• common area maintenance charges;
• insurance increases;
• HVAC maintenance contracts;
• utilities and metering issues;
• waste removal;
• snow removal;
• landscaping;
• management or administration fees;
• repair reserves;
• signage costs;
• parking fees;
• security costs;
• after-hours building access fees.

The lease should explain what can be charged back to the tenant and whether there are limits, exclusions, audit rights, or reporting requirements.

Business owners should ask for historical operating cost information where available. Prior-year costs can help identify whether estimates are realistic.

One high-impact list: what to review before signing a commercial lease

Before signing a commercial lease, business owners should clarify:

• What is the total monthly cost, including base rent, additional rent, utilities, taxes, maintenance, and insurance?
• How will rent increase during the initial term and any renewal term?
• Is there a clear renewal option, and when must it be exercised?
• Who is responsible for repairs, maintenance, HVAC, structural issues, and code compliance?
• Is a personal guarantee required, and can it be limited?
• Can the lease be assigned or sublet if the business is sold, moved, or restructured?
• Does the permitted use clause allow the business to grow or change?
• Can the landlord relocate the tenant or terminate for demolition or redevelopment?
• What happens if the tenant defaults, and is there time to fix the issue?
• Are there hidden costs or operating expenses that may increase over time?

A practical way to protect the business before signing

A commercial lease is one of the most important contracts a business owner may sign. It can affect cash flow, personal risk, location stability, exit options, and the future value of the business.

The best time to review the lease is before it is signed, not after a dispute arises. Once the lease is in place, the business may be committed to obligations that are difficult or expensive to change.

Need help reviewing a commercial lease in Ontario? Pace Law Firm can help business owners understand key lease terms, identify long-term risks, and negotiate practical changes before signing.

FAQs — Commercial Lease Agreements in Ontario

What should I review before signing a commercial lease in Ontario?

Before signing a commercial lease in Ontario, business owners should review the full rent structure, renewal rights, repair obligations, personal guarantees, assignment and subletting rights, permitted use, termination clauses, default remedies, and any additional costs such as taxes, maintenance, insurance, utilities, and common area charges.

What hidden costs can appear in a commercial lease?

Hidden or underestimated costs may include property taxes, common area maintenance fees, building insurance, utilities, HVAC maintenance, waste removal, snow removal, landscaping, management fees, signage costs, parking charges, security costs, and repair-related expenses.

Should I sign a personal guarantee for a commercial lease?

A personal guarantee should be reviewed carefully before signing. It may allow the landlord to pursue the individual business owner personally if the tenant corporation defaults. Business owners should understand whether the guarantee is limited, unlimited, time-limited, or connected to renewals, assignments, damages, legal costs, and additional rent.

What are renewal rights in a commercial lease?

Renewal rights allow a tenant to extend the lease after the initial term if the lease provides that option and the tenant follows the required process. Renewal clauses should be reviewed for notice deadlines, renewal length, rent calculation, default restrictions, and whether all lease terms continue during the renewal period.

Can I assign or sublet a commercial lease?

A tenant may be able to assign or sublet a commercial lease if the lease allows it and any required landlord consent is obtained. Business owners should review whether consent can be withheld, whether fees apply, whether the original tenant remains liable, and whether a sale of the business or change of control triggers assignment rules.

Who is responsible for repairs in a commercial lease?

Repair obligations depend on the wording of the lease. A tenant may be responsible for interior repairs, HVAC, fixtures, glass, utilities, or other maintenance obligations, while the landlord may retain responsibility for certain structural elements. The lease should clearly define who pays for each type of repair.

Why should a business owner have a commercial lease reviewed before signing?

A commercial lease can affect long-term business costs, personal liability, renewal options, repair obligations, transfer rights, termination risk, and hidden expenses. Legal review before signing can help identify risks, clarify obligations, and negotiate changes before the business is committed.