The client
A Calgary homeowner buying her first rental property — a condo she'd already leased before closing, at a rent that comfortably covers its own carrying costs. Her existing principal residence and income were both solid; the only question was how the new rental's numbers would be treated once it hit the ratios.
First rentals are where this question matters most, because there is no track record of the borrower actually managing a second property yet. Every dollar of the lease's credibility comes from the signed document in hand, not from two years of deposits proving the tenant pays — and that is exactly the gap a rental-income policy is written to manage. Two lenders can look at the identical signed lease, the identical subject-property costs, and the identical borrower, and land in two entirely different places, purely on how each one chooses to treat what the lease is worth.
Existing home costs
$2,160/mo
P&I at the qualifying rate, tax and heat, combined
Personal income
$116,000/yr — $9,667/mo
Salaried, stable
Other debt
Car loan $380/mo
Unrelated to either property
New rental
$420,000 condo, Calgary
25% down (illustrative floor, not a regulatory minimum)
Signed lease
$2,350/mo
In hand before closing
Subject mortgage
$315,000
Plus $220/mo property tax on the rental
The problem
The bank's policy for a non-subject rental was an add-back: add half the lease to income, and carry all of the rental's own carrying costs as a liability. That treatment is common, and on a first rental it hits hard, because it grosses income up only a little while loading the full carrying cost onto the liability side.
The add-back arithmetic
- ▸Income used: $9,667 + $1,175 (half the $2,350 lease) = $10,842/mo
- ▸Liabilities: $2,160 existing housing + $380 car + $2,454 full rental carrying costs
- ▸TDS: $4,994 ÷ $10,842 = 46.1% — against a 44% benchmark. Declined.
A rental that comfortably covers itself in real life showed up in the ratios as a net drag — the classic shape of an add-back treatment on a first investment property. The frustrating part for the borrower was that nothing about her file was actually weak: stable employment, a signed lease at a defensible market rent, and an existing home with unremarkable carrying costs. The decline said nothing about any of that. It said only that this particular bank's rental-income policy was not built for a first-time landlord whose lease had not yet had a chance to prove itself with a payment history.
The numbers
This is a straight rental purchase, financed conventionally rather than through default insurance — the 25% down payment here reflects this particular lender's own floor for a non-owner-occupied purchase, not a regulatory minimum, and it's illustrative of what this file's lender required.
| The subject property's qualifying payment | Amount |
|---|---|
| Subject mortgage | $315,000 |
| Contract rate — rental pricing (illustrative, not a quote) | 5.14% |
| Minimum qualifying rate — greater of contract + 2% and 5.25% | 7.14% |
| Monthly P&I at the qualifying rate | $2,234 |
| + subject property tax | $220 |
| Subject carrying costs | $2,454 |
TDS under the bank's add-back
| Add-back TDS line | Figure |
|---|---|
| Existing home costs + car loan | $2,540 |
| Full rental carrying costs | $2,454 |
| Income used (incl. half the lease) | $10,842 |
| TDS vs. a 44% benchmark | 46.1% ✗ |
TDS under an offset lender
Whether a lender treats rental income as an offset against the subject property's own costs, or grosses part of it into income while carrying the full cost as a liability, is illustrative of two common approaches; each lender publishes its own.
| Offset TDS line | Figure |
|---|---|
| Offset: 80% of the $2,350 lease credited against the $2,454 carrying cost | $1,880 offset → $574 shortfall |
| Existing home costs + car loan + rental shortfall | $2,160 + $380 + $574 = $3,114 |
| Income used (no rent added) | $9,667 |
| TDS vs. the 44% benchmark | 32.2% ✓ |
Under the offset, only the $574 gap between the lease and the rental's own carrying cost reaches the liability side. The identical file swings almost fourteen TDS points on treatment alone — without a single input to either lender changing. Not the lease, not the existing home's carrying costs, not the borrower's income or her car payment. The only variable in motion was which of two published policies the file happened to land under.
The solution
A RECA-licensed Alberta mortgage associate diagnosed the decline as a policy mismatch, not a numbers problem, and matched the file accordingly.
First, re-ran the TDS under both common treatments before submitting anywhere a second time — confirming the deal lived or died on which lender's rental policy it landed with, not on the underlying strength of the file.
Second, moved the file to a lender whose published policy offsets rental income against the rental's own carrying costs, taking only the shortfall — not the gross costs — into TDS.
Third, packaged the lease and both properties' numbers clearly, so the underwriter could see the existing home's costs, the rental's costs, and the signed lease side by side.
The outcome
Funded at the offset lender's terms, uninsured. Alberta has no land transfer tax; closing costs there run through Land Titles Office registration fees on a sliding scale instead, and the current fee schedule for this file wasn't independently confirmed, so it stays qualitative here rather than quoted as a dollar figure.
The rental now sits alongside the principal residence on a file that, properly placed, never needed a B-lender detour at all — only a lender whose rental policy matched how the property actually performs. That distinction is worth sitting with: a first rental purchase is not automatically a harder file than a second, third or fourth one. It is a file where the borrower has the least track record to lean on, which is exactly why the choice of lender policy carries more weight here than it will once the portfolio has a payment history of its own.
What to take from this file
- 01Same borrower, same lease, two different lenders' policies can produce wildly different TDS. This file swung from 46.1% (add-back) to 32.2% (offset). Run both before you pick a lender.
- 02An offset treatment only ever puts the shortfall into liabilities. An add-back grosses up income a little but loads the full carrying cost onto the liability side — which is usually why it loses.
- 03Down payment floors on a straight rental purchase are lender policy, not a default-insurance minimum. Confirm the actual floor with the lender you're placing, not the owner-occupied insured rule.
- 04The existing principal residence's own carrying costs stay in the math no matter what. They don't disappear just because the new property is a rental.
- 05Alberta has no land transfer tax; Land Titles Office registration fees apply on a different sliding scale. Quote them qualitatively unless you've confirmed the current fee schedule.
Sources
Every regulatory figure in this file traces to one of these primary sources. Client details and anything that varies by lender are illustrative, as flagged below.
- ▸OSFI — Minimum qualifying rate for uninsured mortgages — the minimum qualifying rate — greater of contract rate + 2% or 5.25%.
- ▸Provincial/territorial mortgage-broker legislation fetched directly (bclaws.gov.bc.ca, legisquebec.gouv.qc.ca, fcaa.gov.sk.ca, web2.gov.mb.ca, nslegislature.ca, assembly.nl.ca) plus FCNB's own site for NB and CanLII's index for PE — see notes for per-province method — provincial mortgage regulators and licence titles.
Illustrative in this file — lender-specific, not rules:
- ▸50% add-back / 80% offset — each lender publishes its own rental treatment.
- ▸25% down on a rental purchase — rental down-payment floors are lender policy.
- ▸5.14% rental pricing — illustrative, not a quote.
Authority & provenance
How this case file was built
We publish the origin, the verification method and the reviewer for every case file, so you can judge how far to trust it before you rely on it with a client.
Where it comes from
Derived from files handled by Treadstone’s fulfillment desk and from scenarios contributed by partner brokerages. Names, employers, exact amounts and dates are changed so no client or file is identifiable.
Provenance: Composite — a pattern seen repeatedly on fulfilled files, not a single transaction.
What is verified
Every regulatory figure traces to a primary source listed above and was checked against it on the date shown. The arithmetic is recomputed by machine on every rebuild.
Anything that varies by lender is labelled illustrative rather than stated as a rule.
Who reviewed it
Reviewed for Canadian regulatory accuracy before publication, and re-checked whenever a cited rule changes.
Reviewed by: Nicholas Parson, Treadstone Associates — reviews every case file before publication.
This case file is professional reference material for licensed mortgage professionals. It is not advice to a borrower, and it is not a lender commitment. Insurer rules, qualifying rates and provincial taxes change — confirm the current position with the insurer, regulator or lender before you rely on any figure here in a live file.