The client
A greenhouse vegetable-growing business owner near Leamington, with standing supply contracts to major produce distributors — the kind of contracted, year-round revenue that makes a greenhouse operation's income far steadier than an open-field farm's. His spouse earns $3,800/mo. They wanted to buy a $545,000 home at 20% down.
Borrower
Greenhouse vegetable grower, sole proprietor
Contracted revenue with major produce distributors
Spouse's income
$3,800/mo
Gas-spike year net
$58,000
Absorbed a $22,000 one-time heating cost spike
Following year net
$81,000
No comparable cost anomaly
New purchase
$545,000, Leamington
Property tax $460/mo; lender-standard heat $170/mo
Down payment
$109,000 — 20%
Uninsured, no default-insurance premium
The two T1 years, side by side — the low year is the one with the heating-cost spike:
| Business income | Gas-spike year | Following year |
|---|---|---|
| Reported T1 net income | $58,000 | $81,000 |
| One-time natural-gas heating cost spike, added back | $22,000 | — |
| Adjusted net once the spike is added back | $80,000 | $81,000 |
The problem
One year's reported net of $58,000 absorbed a $22,000 spike in natural-gas heating costs during an abnormal pricing period. A straight two-year average against the following $81,000 year gives just $5,792/mo, pushing TDS to 40.8% — over the 40% internal comfort line the uninsured lender wanted to see, even though CMHC's regulatory ceiling does not formally apply to an uninsured file.
What the heating-cost spike actually distorted
- ▸Straight average, gas-spike year included as-is: ($58,000 + $81,000) ÷ 2 ÷ 12 = $5,792/mo.
- ▸Combined with the spouse's income: $9,592/mo. TDS: 40.8%.
- ▸Once the $22,000 spike is added back to that year: $6,708/mo average, combined income $10,508/mo. TDS: 37.2%.
A greenhouse operation's revenue does not swing with a single harvest the way an open-field farm's can — its supply contracts hold steady year-round. What moved this business's reported net was an input-cost anomaly on the heating side, not a change in what it grew or sold.
The numbers
At 20% down (80% LTV) this file is conventional/uninsured — no default-insurance premium applies, and there is no CMHC ratio ceiling, though the lender still applies its own internal comfort line.
| The uninsured purchase | Amount |
|---|---|
| Purchase price | $545,000 |
| Down payment (20%) | −$109,000 |
| Base mortgage (80% LTV, no default-insurance premium) | $436,000 |
| Rate & payments | Figure |
|---|---|
| Contract rate — 5-year fixed (illustrative, not a quote) | 4.69% |
| Minimum qualifying rate — contract + 2% | 6.69% |
| Monthly P&I at the qualifying rate — the ratios run on this | $2,971 |
| Monthly P&I at the contract rate — what he actually pays | $2,459 |
TDS, unadjusted versus the corrected average
| TDS line | Unadjusted average | Gas-spike added back |
|---|---|---|
| Income used | $9,592/mo | $10,508/mo |
| Housing (qualifying payment + $460 tax + $170 heat) | $3,601 | $3,601 |
| TDS (housing + $310 truck loan ÷ income) | 40.8% | 37.2% |
Because this file is uninsured there is no CMHC ratio ceiling — the two figures show the improvement against the lender's own internal comfort line, the same kind of discipline documented in how Canadian lenders actually read self-employed business income, not a regulatory pass/fail line.
The solution
An FSRA-licensed Ontario mortgage agent traced the low year to a specific, dated cost anomaly rather than treating it as ordinary volatility.
First, confirmed the greenhouse's revenue side was stable. Supply contracts with the same distributors covered both years at comparable volumes and pricing — the top line never moved the way a farm's harvest-driven revenue might.
Second, isolated the cost side. The utility's own rate filings for the period confirmed an abnormal natural-gas price spike coinciding exactly with the low-net year, accounting for the $22,000 gap between the two years' heating costs.
Third, added the documented spike back before averaging — the same add-back logic used throughout self-employed income calculations, applied to an input-cost anomaly instead of the more familiar CCA or home-office claims.
The outcome & the closing math
Funded uninsured at 4.69%, 25-year amortization, 80% LTV. Because the file is uninsured there is no default-insurance premium and therefore no premium tax, but Ontario's land transfer tax still applies to the purchase:
| Cash due at closing (beyond the down payment) | Amount |
|---|---|
| Ontario land transfer tax on $545,000 — marginal brackets | $7,375 |
| Legal fees, title insurance & adjustments | varies |
At 20% down, this file never needed a premium calculation at all — the entire underwriting question was the income averaging, not the loan structure.
What to take from this file
- 01A greenhouse business's income volatility often comes from input costs, not the harvest. Check utility and heating costs before assuming a low year reflects weaker sales.
- 02A documented, dated cost spike is a defensible add-back the same way a one-time CCA claim is. Confirm it against the supplier's or utility's own records, not just the borrower's account of it.
- 03An uninsured file's TDS is measured against a lender's own comfort line, not a CMHC ceiling — know which one applies before framing the ask.
- 04At 20% down there is no premium to calculate, which simplifies the loan structure and puts the full underwriting focus on the income question.
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%.
- ▸Ontario.ca — Calculating Land Transfer Tax / Land Transfer Tax Refunds for First-Time Homebuyers — Ontario's marginal land transfer tax brackets and first-time-buyer refund.
- ▸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:
- ▸4.69% contract rate — rates move daily; not a quote.
- ▸the TDS figures — this file is uninsured, so there is no CMHC ratio ceiling -- the numbers show the improvement against the lender's own internal comfort line, not a regulatory pass/fail line.
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.