Two spaces quoted at the same rate can cost different amounts. It depends on how the rent is quoted and how the square feet are measured. Checked October 4, 2026.
Per square foot, per year
Commercial rent is quoted per square foot per year. At $24 per square foot on 2,000 square feet, the rent is $48,000 a year, or $4,000 a month, before TMI and HST. A common mistake is reading $24 as a monthly figure.
Usable and rentable area
- Usable area: the space you actually occupy.
- Rentable area: your usable area plus your share of common areas such as lobbies, corridors and shared washrooms.
- Load factor: the difference between the two. Example: 1,800 usable square feet with a 10% load factor is billed as 1,980 rentable square feet.
- Rent and TMI are often charged on the rentable area, so the load factor raises your real cost per usable foot.
In a plaza unit with its own front door there may be little or no common area. In an office building the load factor matters more. Many landlords measure using industry standards such as those published by BOMA.
What to ask
- Is the quoted area rentable or usable?
- What is the load factor?
- Who measured the space, when, and to which standard?
- If the space is remeasured later, does the rent change?
Commercial rent also carries 13% HST in Ontario. Put the area and rates into the commercial lease calculator to see the monthly cost, and read what TMI covers.
Sources (official pages, checked October 4, 2026)
- CRA – GST/HST rates (Ontario 13%)
- CRA GST/HST Memorandum 19.4.1 – Commercial real property, sales and rentals (a commercial lease is a taxable supply)
- Ontario – Renting commercial property in Ontario (Commercial Tenancies Act, updated July 2, 2026)
Programs and limits change, often at budget time. Confirm the current rules on the official page before you rely on them.
Talk to me in English or Arabic: call or text (647) 465-3710, message me on WhatsApp, or email Mohieddinrealtor@gmail.com.
General information only – not financial, legal or mortgage advice. Please consult a licensed professional about your own situation.