Commercial Real Estate Due Diligence Checklist for Ontario Buyers and Sellers

A commercial real estate due diligence checklist in Ontario should cover six areas: title and legal, leases and income, financial records, physical condition, environmental condition, and zoning and planning. Due diligence is the period between an accepted offer and closing in which a buyer verifies that the property is what it was represented to be. For a seller, it is the stage where deals are most often repriced or lost. This checklist is written for both sides: buyers who need to know what to examine and in what order, and sellers who want to have the answers ready before a buyer asks. It applies to income-producing properties, owner-user buildings and land across the GTA and Southern Ontario.

Why Due Diligence Matters More in Commercial Transactions

Residential buyers rely heavily on a home inspection and a title search. A commercial property has more moving parts: tenants with contractual rights, income that has to be verified, environmental history, zoning that may or may not permit the use, and building systems that have a real capital cost. The offer price is usually built on assumptions about income and condition, and due diligence is the process of testing those assumptions. Findings can justify closing as agreed, renegotiating the price, requesting a credit or extending the period, or walking away under the conditions written into the agreement of purchase and sale.

The conditions period is short and fixed, so preparation matters. Buyers should line up their lawyer, lender, environmental consultant and building consultant before the offer is submitted, not afterward. Sellers should treat due diligence readiness as part of marketing the property, because a buyer who can get complete, consistent documents quickly is less likely to renegotiate.

1. Title, Survey and Legal Review

The buyer’s lawyer leads this work. It typically includes:

• A title search and review of registered instruments: mortgages, liens, easements, rights-of-way, restrictive covenants and any notices registered against title.
• A current survey or reference plan, checked against the legal description for encroachments, boundary issues and the location of easements.
• Confirmation that the seller has the authority to sell and that any existing charges will be discharged on closing.
• Review of any pending or threatened litigation, work orders or outstanding notices.
• Confirmation of the tax and HST treatment of the transaction. See the note on HST and land transfer tax below.

2. Leases, Rent Roll and Tenants

For an income-producing property, the leases are the asset. Ask for and review:

• Rent roll. Each tenant, suite, area, current rent, lease start and expiry, options, deposits and arrears.
• Every lease and amendment. The rent roll is a summary; the lease governs. Look at term, renewal options, rent escalations, operating cost and tax recovery provisions, exclusives, rights of first refusal, termination rights, assignment and subletting, and any landlord obligations.
• Tenant estoppel certificates. A signed confirmation from each tenant of the lease terms, rent paid, deposits held and whether any defaults or disputes exist. Estoppels are one of the best ways to catch a mismatch between what the seller says and what the tenant believes.
• Subordination, non-disturbance and attornment agreements where the buyer’s lender requires them.
• Tenant quality. Financial strength, industry, payment history and how central the space is to the tenant’s business. A strong covenant lowers risk and can support a lower cap rate. Our article on how commercial property value is calculated explains how those factors reach the price.
• Side agreements. Verbal concessions, free rent, or landlord commitments that are not in the written lease.

3. Financial Review

The financial review confirms that the income and expenses behind the asking price are real. Request:

• Trailing twelve-month operating statement and at least three prior years.
• General ledger or bank records sufficient to reconcile reported income.
• Realty tax bills and assessment notices, insurance policies and premiums, utility invoices and service contracts.
• Operating cost and tax reconciliations issued to tenants, and any outstanding recoveries.
• Details of capital work completed in recent years.

Use this information to rebuild net operating income independently instead of relying on the seller’s figure. Our guide on how to calculate NOI sets out the line items and the common classification errors. Then compare the result against the price and the cap rate you are being asked to pay.

4. Physical Condition

A building condition assessment by a qualified consultant is standard on any property of meaningful size. It should address:

• Roof age, condition and remaining life.
• Structure, foundation, building envelope and parking structures.
• Heating, ventilation and air conditioning, electrical capacity, plumbing and elevators.
• Fire protection systems, sprinklers and life-safety equipment.
• Paving, drainage, lighting and site services.
• Accessibility and code compliance issues.
• Estimated near-term and long-term capital expenditures.

The capital cost estimate matters as much as the list of defects. Deferred maintenance is a legitimate price adjustment, and a buyer who understands the true capital requirement can negotiate with facts instead of general concerns.

5. Environmental Due Diligence

Environmental risk can exceed the value of a building and stay with the owner, so it deserves its own workstream. The standard first step is a Phase I environmental site assessment (ESA): a records review, site inspection and interviews to identify whether past or present activities may have contaminated the property. In Ontario, Phase I ESAs are commonly done to the Canadian Standards Association Z768 standard, or to the requirements of Ontario Regulation 153/04 where the work is intended to support a Record of Site Condition.

If the Phase I identifies potential areas of concern, a Phase II ESA involves sampling of soil, groundwater or building materials to test for contamination. Some property types warrant particular attention: gas stations, automotive repair, dry cleaners, industrial and manufacturing sites, and any property near them.

A Record of Site Condition (RSC) filed in Ontario’s Environmental Site Registry is required before the use of a property is changed to a more sensitive use, for example from industrial or commercial to residential, institutional or parkland. Buyers planning redevelopment should raise this with their consultant and lawyer at the outset, because it affects both timing and cost. Sellers of properties with a history of industrial or automotive use are usually better served by knowing what a Phase I will say before a buyer commissions one.

6. Zoning, Planning and Compliance

• Zoning by-law. Confirm the property’s zoning, permitted uses, and whether the current use is permitted, legal non-conforming or in breach.
• Official Plan designation. Especially important for development land and for properties in employment areas, where the planning framework governs what can be built or converted.
• Compliance letters. Municipalities generally provide information on building permits, open work orders, zoning compliance and fire department inspections, often for a fee. Order them early because turnaround varies.
• Building permits and occupancy. Verify that additions, tenant improvements and changes of use were permitted and closed.
• Development charges and other levies. Relevant where the buyer plans an expansion or redevelopment.
• Heritage designation, site plan agreements and other registered obligations that limit what can be done with the site.

Ontario’s Provincial Planning Statement, 2024 came into effect on October 20, 2024 and sets the provincial policy framework municipalities apply, including how employment areas are protected. A local planner or land-use lawyer can advise how it applies to a specific site.

7. Taxes, HST and Closing Costs

Understand the total cost of acquisition, not just the price:

• Ontario land transfer tax. For non-residential property, the Province of Ontario’s published rates are 0.5% up to $55,000, 1.0% from $55,000 to $250,000, 1.5% from $250,000 to $400,000, and 2.0% above $400,000. In the City of Toronto, a municipal land transfer tax applies in addition, using the same brackets for non-residential property. Confirm current rates with your lawyer before closing.
• HST. The sale of commercial real property is generally a taxable supply. Under the Excise Tax Act, where the purchaser is a GST/HST registrant, the vendor generally is not required to collect the tax and the purchaser self-assesses it; where the purchaser is not registered, the vendor must collect it. Special rules and elections apply to sales of a business as a going concern, so this needs to be addressed in the agreement and confirmed with your accountant.
• Realty tax adjustments and the prorating of rents, deposits and prepaid items on closing.
• Financing costs, including lender appraisal, legal, environmental and building reports. Our overview of financing a commercial property in Ontario explains what lenders typically require.

Common Due Diligence Mistakes

• Starting late. Reports, estoppels and municipal letters take time. A late start turns a routine condition into a request for an extension.
• Relying on the rent roll alone. The lease, not the summary, governs the tenant’s rights.
• Skipping the environmental review to save money. The cost of a Phase I is small compared with the exposure it is designed to identify.
• Not pricing the capital work. A defect list without cost estimates is difficult to negotiate from.
• Assuming zoning permits the intended use. Confirm it in writing; do not rely on the listing description.
• Letting conditions lapse by default. Track every condition date and deliver waivers or extensions properly and in writing, with your lawyer’s advice.
• Sellers who produce documents piecemeal. Inconsistent or late information creates doubt and gives buyers a reason to renegotiate.

Frequently Asked Questions

How long is the due diligence period for a commercial property in Ontario?

It is negotiated and written into the agreement of purchase and sale. It varies with the size and complexity of the property, and environmental work or municipal responses can require more time than a simple building.

What is a tenant estoppel certificate?

It is a document signed by a tenant confirming the key terms of its lease, the rent being paid, deposits held and whether there are any defaults or disputes. Buyers and lenders use it to verify what the seller has represented.

Do I need a Phase I environmental assessment?

It is not required by law for every purchase, but most lenders and prudent buyers require one, and it is particularly important for properties with industrial, automotive or fuel history.

What is a Record of Site Condition?

It is a filing in Ontario’s Environmental Site Registry that documents a property’s environmental condition. It is required before a property’s use is changed to a more sensitive use, such as residential.

Who pays for due diligence reports?

Buyers normally commission and pay for their own reports. Sellers generally bear the cost of gathering and producing their own records and, in some transactions, may commission reports in advance.

Can a buyer walk away during due diligence?

If the agreement contains a due diligence or inspection condition for the buyer’s benefit, the buyer can generally terminate within the condition period as the agreement provides. The exact rights depend on the wording, so have a lawyer review it.

What is the difference between an appraisal and due diligence?

An appraisal estimates value. Due diligence verifies the property’s legal status, income, condition and risks that the value is based on. Both are typically required for financing.

Should sellers prepare their own due diligence package?

Yes. Assembling the leases, financials, reports and compliance documents before listing shortens the buyer’s review and reduces the chance of late surprises.

Conclusion

Good due diligence is organized, early and documented. Verify title and leases first, rebuild the income from actual records, price the physical and environmental risk, and confirm that zoning and planning allow what you intend to do. The same discipline helps sellers, because the transactions that close on the agreed terms are usually the ones where both sides understood the property long before conditions were due. If you are considering buying or selling a commercial property in the GTA or Southern Ontario, a property-specific valuation and market strategy can help you understand your options before entering the market.

Sources and Further Reading

• Government of Ontario: Guide on site assessment, the cleanup of brownfield sites and the filing of Records of Site Condition
• Government of Ontario: Ontario Regulation 153/04, Records of Site Condition
• Government of Ontario: Calculating land transfer tax
• City of Toronto: Municipal land transfer tax rates and fees
• Canada Revenue Agency: GST/HST Memorandum 19-4-1, Commercial Real Property – Sales and Rentals
• Government of Ontario: Provincial Planning Statement, 2024

This checklist is general information and is not legal, tax, accounting, environmental or engineering advice. Every transaction is different; consult qualified professionals before relying on it.