Mortgage Financing Explained

Tim Lyon • May 23, 2024

If you’re like most Canadians, chances are you don’t have enough money in the bank to buy a property outright. So, you need a mortgage. When you’re ready, it would be a pleasure to help you assess and secure the best mortgage available. But until then, here’s some information on what to consider when selecting the best mortgage to lower your overall cost of borrowing.


When getting a mortgage, the property you own is held as collateral and interest is charged on the money you’ve borrowed. Your mortgage will be paid back over a defined period of time, usually 25 years; this is called amortization. Your amortization is then broken into terms that outline the interest cost varying in length from 6 months to 10 years. From there, each mortgage will have a list of features that outline the terms of the mortgage.


When assessing the suitability of a mortgage, your number one goal should be to keep your cost of borrowing as low as possible. And contrary to conventional wisdom, this doesn’t always mean choosing the mortgage with the lowest rate. It means thinking through your financial and life situation and choosing the mortgage that best suits your needs.


Choosing a mortgage with a low rate is a part of lowering your borrowing costs, but it’s certainly not the only factor. There are many other factors to consider; here are a few of them:


  • How long do you anticipate living in the property? This will help you decide on an appropriate term.
  • Do you plan on moving for work, or do you need the flexibility to move in the future? This could help you decide if portability is important to you.
  • What does the prepayment penalty look like if you have to break your term? This is probably the biggest factor in lowering your overall cost of borrowing.
  • How is the lender’s interest rate differential calculated, what figures do they use? This is very tough to figure out on your own. Get help. 
  • What are the prepayment privileges? If you’d like to pay down your mortgage faster.
  • How is the mortgage registered on the title? This could impact your ability to switch to another lender upon renewal without incurring new legal costs, or it could mean increased flexibility down the line.
  • Should you consider a fixed rate, variable rate, HELOC, or a reverse mortgage? There are many different types of mortgages; each has its own pros and cons. 
  • What is the size of your downpayment? Coming up with more money down might lower (or eliminate) mortgage insurance premiums, saving you thousands of dollars.


So again, while the interest rate is important, it’s certainly not the only consideration when assessing the suitability of a mortgage. Obviously, the conversation is so much more than just the lowest rate. The best advice is to work with an independent mortgage professional who has your best interest in mind and knows exactly how to keep your cost of borrowing as low as possible.


You will often find that mortgages with the rock bottom, lowest rates, can have potential hidden costs built in to the mortgage terms that will cost you a lot of money down the road. Sure, a rate that is 0.10% lower could save you a few dollars a month in payments, but if the mortgage is restrictive, breaking the mortgage halfway through the term could cost you thousands or tens of thousands of dollars. Which obviously negates any interest saved in going with a lower rate.


It would be a pleasure to walk you through the fine print of mortgage financing to ensure you can secure the best mortgage with the lowest overall cost of borrowing, given your financial and life situation. Please connect anytime!


Tim Lyon

Mortgage Consultant

By Tim Lyon January 25, 2026
Trying to choose between a 25 and 30 year mortgage amortization? Learn how each affects your payments, interest, and flexibility so you can decide with confidence.
By Tim Lyon January 20, 2026
If you are buying a home with a suite, keeping your current home as a rental, or already own a rental property, mortgage qualification can get confusing fast. The frustrating part is that you can do everything “right” and still get very different answers depending on which lender you talk to. Here’s a simple breakdown so you understand it and don’t miss out. What are Debt Service Ratios? In Canada, lenders qualify you using two main ratios: Gross Debt Service (GDS) This looks at housing costs only , typically: Mortgage payment Property taxes Heating 50% of strata fees (if applicable) GDS typically needs to be 39% or less of your gross income. Total Debt Service (TDS) This includes everything in GDS , plus other debts like: Car loans Credit cards Lines of credit Student loans TDS typically needs to be 44% or less of your gross income. These ratios are the foundation. If they do not work, the lender will not approve the mortgage, even with strong credit and a solid down payment. How Lenders Treat Rental Income Most people assume lenders look at rental properties based on simple cash flow (rent minus mortgage payment). In reality, most lenders use one of two methods: 1) Addback A percentage of the rental income is added to your gross income for qualification purposes. 2)Offset A percentage of the rental income is subtracted from the mortgage payment tied to the rental property. Different lenders use different percentages and different worksheets. That is why the same borrower can qualify with one lender and fail with another. Benefits of Understanding Lender Methods When you understand how rental income is calculated, you can: Avoid being under-qualified by a lender with conservative rules Get a more accurate picture of your real purchasing power Choose a lender that fits your situation (instead of forcing your situation to fit the lender) Important Considerations A few key points to keep in mind: Rental income is rarely counted at 100% , but some lenders are more generous than others. The method matters just as much as the percentage (addback vs offset). If you own multiple properties, lender worksheets can change the result dramatically. Your lender choice is a strategy decision , not just a rate decision. Real-World Example: Same Clients, Two Very Different Outcomes Here’s an example comparing lenders Scotiabank and Strive, using a fictitious couple: Scenario Household income: $160,000 Existing townhome: $800,000 value with a $525,000 mortgage ( $2,500/month payment) Market rent for the townhome: $3,400/month New purchase: property with a rental suite generating $1,800/month Down payment: 10% Other debts: student loan $165/month , car loan $500/month How Scotiabank viewed it For the townhome rental, they counted half the rent and subtracted the mortgage payment, leaving an $800/month shortfall that gets added into the debt ratios. For the new purchase, 50% of the suite income gets added to income. Max mortgage : $650,700 Max purchase price : $723,000 How Strive viewed it For the townhome rental, Strive used a rental worksheet and calculated $5.20/month of income that can be added to the application. For the new purchase, 100% of the suite income gets added to income, and they did not need to include taxes or heat. Max mortgage : $878,400 Max purchase price : $976,000 The result That’s a $253,000 difference in purchasing power , with the same clients, same income, same debts, and same properties. The difference was lender policy. Quick Summary GDS and TDS ratios are the backbone of mortgage qualification. Rental income is usually counted using Addback or Offset , and each lender handles this differently. Two lenders can produce wildly different results, even with the exact same file. In the example above, lender choice created a $253,000 swing in purchasing power. Next Steps If you are planning to: Buy a home with a suite Keep your current home and convert it to a rental Use rental income to qualify Reach out and I will run the numbers across multiple lenders so you see what you actually qualify for, not just what one lender will allow. Need help with your mortgage? Book a consultation or call 778-988-8409 . Glossary Addback : A method where a lender adds a percentage of rental income to your gross income for qualification. Gross Debt Service (GDS) : The ratio that measures housing costs as a percentage of gross income. Offset : A method where a lender subtracts a percentage of rental income from the rental property’s mortgage payment for qualification. Total Debt Service (TDS) : The ratio that measures housing costs plus other debts as a percentage of gross income.