Cap Rates and DSCR: How Lenders Underwrite Commercial Deals

What Actually Drives a Commercial Mortgage Approval

If you have ever tried to finance a commercial property and walked away confused, you are not alone. Commercial underwriting is a different world from residential lending. Lenders are not primarily focused on your personal income or credit score — they are focused on whether the property itself can carry the debt. Two metrics sit at the centre of every commercial credit decision: the capitalization rate (cap rate) and the debt service coverage ratio (DSCR).

Understanding both of these will help you structure deals properly, negotiate more effectively, and avoid wasting time on financing that was never going to work.

Cap Rate: The Lender's Valuation Compass

The cap rate is a measure of a property's income relative to its value. The formula is straightforward:

Cap Rate = Net Operating Income (NOI) / Property Value

For example, if a property generates $120,000 in NOI and is valued at $1,500,000, the cap rate is 8%.

Lenders use cap rates in two critical ways.

1. Confirming Market Value

When a lender orders an appraisal on a commercial property, the appraiser derives value partly by dividing the NOI by a market cap rate. That market cap rate is pulled from comparable sales in the area. If the comparable cap rate for similar retail plazas in Brampton is 6%, and your property generates $90,000 in NOI, the appraiser arrives at a value of $1,500,000 — regardless of what you paid or what the seller is asking.

This is why commercial lenders care deeply about local market cap rates. A property purchased at a compressed cap rate in a heated market may appraise lower than the purchase price, which directly affects how much the lender will advance.

2. Stress-Testing the Deal

Some institutional lenders and CMHC programs apply their own underwriting cap rate, which may be higher than the market cap rate, to be conservative. They essentially ask: what is this property worth if the market softens? A lender might use a 7% underwriting cap rate even if market cap rates for that asset class are sitting at 5.5%. This results in a lower appraised value for lending purposes, reducing their loan-to-value (LTV) exposure.

As a borrower, you need to know which cap rate framework your lender is using. It has a direct impact on how much equity you will need to bring to the table.

Net Operating Income: The Foundation of Everything

Before you can understand DSCR, you need a clean NOI figure. NOI is calculated as:

NOI = Gross Rental Income – Vacancy Allowance – Operating Expenses

Operating expenses typically include:

Property taxes
Insurance
Property management fees
Maintenance and repairs
Utilities (if landlord-paid)
Reserve for capital replacements

Note what is excluded: mortgage payments are not an operating expense. NOI is a pre-financing number. That is intentional, because lenders want to evaluate the property's standalone income potential independent of how it is financed.

Lenders will not simply accept your rent roll at face value. They will normalize the income by applying a vacancy factor — typically 5% to 10% depending on asset class and market — even if the building is 100% occupied today. They may also adjust management fees upward if you are self-managing, because a new owner or a distressed scenario would require professional management.

DSCR: The Number That Determines Whether You Get the Loan

Once NOI is established, lenders calculate the DSCR:

DSCR = NOI / Annual Debt Service

Annual debt service means the total principal and interest payments on the mortgage over one year.

Most conventional commercial lenders require a minimum DSCR of 1.20, meaning the property must generate at least $1.20 in NOI for every $1.00 of debt service. CMHC-insured multi-family programs may have different thresholds depending on the program. Some lenders require 1.25 or even 1.30 for asset classes they view as higher risk, such as hospitality or specialized industrial.

Why DSCR Determines Loan Size, Not Just Approval

Here is where borrowers are often surprised. You may qualify for a loan in principle, but DSCR constrains how large that loan can be. A lender will size the mortgage so that payments never push the DSCR below their minimum threshold.

Consider this example:

NOI: $150,000
Lender minimum DSCR: 1.25
Maximum allowable annual debt service: $150,000 / 1.25 = $120,000
At current amortization and rate assumptions, $120,000 in annual payments may only support a mortgage of, say, $1,600,000

Even if the appraised value would allow a higher LTV, the DSCR ceiling caps the loan. You must bridge the gap with equity.

How These Two Metrics Interact in Practice

Cap rate and DSCR are not independent calculations — they interact. A lender effectively runs both tests and advances the lesser of what each metric allows.

If cap rates in the market are low (meaning valuations are high relative to income), the LTV test may allow a substantial loan, but the DSCR test may restrict it because the income is thin relative to the debt payments. Conversely, in a high-cap-rate environment, the appraised value may be lower, restricting LTV even if the income coverage is strong.

This intersection is where experienced mortgage brokers add real value. Structuring the deal — adjusting amortization, exploring blended financing options, or identifying lenders with more flexible underwriting parameters — can meaningfully change what you are able to borrow.

Common Mistakes Borrowers Make

Borrowers who are new to commercial financing frequently run into the same set of problems:

Overstating gross income by ignoring vacancy or including non-recurring revenue
Understating operating expenses by excluding management fees or capital reserves
Assuming purchase price equals appraised value when lenders derive value from income
Presenting leases without reading the fine print — lenders scrutinize lease terms, tenant covenants, and remaining lease duration carefully
Approaching the wrong lender for the asset class — a lender comfortable with multi-family may not have appetite for a mixed-use retail plaza

What You Should Prepare Before Applying

If you are bringing a commercial deal to a lender, have the following ready:

Current rent roll with lease start and end dates
Two to three years of operating statements
Current property tax bills
Insurance declarations
Details of any capital improvements completed or planned
A narrative on tenant quality and lease structure

The cleaner and more complete your package, the faster the underwriter can work and the more confidence they have in your numbers.

Work With a Broker Who Knows Commercial Underwriting

Commercial lending is not a commodity product. Different lenders apply different underwriting cap rates, DSCR thresholds, and LTV limits depending on asset class, geography, and their own portfolio strategy. Knowing where to place a deal — and how to present it — can be the difference between a competitive approval and a decline.

At Empower Approved Mortgage Solutions, we work with investors and business owners across Ontario on commercial financing across a wide range of asset classes. Whether you are acquiring your first income property or refinancing an existing portfolio, we help you understand the numbers before you walk into a lender's office. Reach out to Sunny Singh at sales@empowerapproved.ca or call (647) 775-0823 to discuss your commercial financing needs.