The client
A family building a new self-build in Prince Albert, Saskatchewan, while their existing home was still listed for sale. Combined income of $7,600/month comfortably supports one mortgage — the question was what happens to the ratios while it briefly has to support two.
Existing home mortgage
$240,000 balance, 4.50%
17 years remaining amortization
New construction facility
$310,000 total, take-out at completion
$285,000 drawn at the peak, before the old home sold
Income
Combined $7,600/month
Both salaried, stable employment
Other debt
$280/mo car loan
the only item on either bureau file
The overlap
Several months carrying both properties
Between breaking ground and the old home's sale
The problem
A self-build doesn't wait for an old home to sell before construction starts — draws release against progress, on the project's own schedule. For a family still carrying an existing mortgage, that means a stretch of months where the old home's full payment and the new build's interest-only construction draws both come due at the same time, on the same household income.
The overlap, priced out
- ▸Existing home: payment at 4.50%, $240,000 balance, 17 years remaining: $1,680/mo
- ▸New construction facility: interest-only on $285,000 drawn at the peak, at 6.75%: $1,603/mo
- ▸Combined with tax, heat and the car loan, total debt service reached 51.2%
51.2% is not a number any lender wants to see as a settled position. Read on its own, without context, it looks like a household that has overextended itself. Read as a temporary overlap against a firm sale already in motion, it is a completely ordinary feature of building before selling — the difference is entirely in how the file is structured, not in the household's actual finances.
The numbers
The math never suggested a permanent problem. Once the old home sells and its mortgage discharges, the new build's take-out mortgage funds on its own, at a TDS well inside comfortable range — the overlap was always going to resolve itself on a calendar, not on a restructuring.
| The overlap, and the take-out that follows it | Amount |
|---|---|
| Existing mortgage payment (4.50%, $240,000 balance) | $1,680/mo |
| New construction draws, interest-only on $285,000 at 6.75% | $1,603/mo |
| Combined carrying cost during the overlap | $3,283/mo |
| New build take-out mortgage, once construction completes | $310,000 |
| Take-out payment at the qualifying rate, 25 years | $2,124/mo |
| Total debt service | During the overlap | After the old home sells |
|---|---|---|
| Housing costs used in the ratio | $1,990 (old home, incl. tax/heat) | $2,514 (new build, incl. tax/heat) |
| Construction draws | $1,603 | — (converted to the take-out mortgage above) |
| Car loan | $300 | $300 |
| Total debt service | 51.2% ✗ | 37.0% ✓ |
The take-out payment itself, $2,124/mo at the qualifying 6.75% rate, never changed regardless of when the old home sold. Every point of the 14-point gap between 51.2% and 37.0% came from the old mortgage disappearing from the household's obligations, not from any change to the new build.
The solution
A mortgage broker licensed under Saskatchewan's Financial and Consumer Affairs Authority (FCAA) structured the overlap explicitly as a temporary bridge, not an open-ended hope that the numbers would sort themselves out.
First, confirmed the old home had a firm, unconditional sale agreement before the overlap period was ever presented to a lender as a bridge. A listing alone is a plan; a firm agreement is a documented exit — the same distinction that underlies ordinary bridge financing between an ordinary purchase and sale.
Second, sized the construction facility's peak draw against the project's own schedule, not against how much the family might have wanted available at once — keeping the interim carrying cost as small as the build itself allowed.
Third, kept the take-out mortgage's terms locked and separate from the bridge period's math. The $310,000 take-out at completion never depended on how the overlap resolved; only the household's month-to-month cash flow did, which is exactly what bridge financing between two closings is built to absorb.
The outcome
The old home sold on schedule, its $240,000 mortgage was discharged from the sale proceeds, and the new build's take-out mortgage funded at $310,000 with TDS settling at 37.0%. The 51.2% overlap never had to be argued as a permanent ratio — only bridged as a temporary one, exactly as structured from the start.
Because the overlap was documented against a firm sale rather than a listing, the file never needed to be re-underwritten from scratch once the sale closed — the take-out simply proceeded on the terms already agreed.
What to take from this file
- 01Carrying two properties during a self-build is an ordinary, solvable overlap, not a permanent red flag. 51.2% looks alarming in isolation and unremarkable against a documented exit.
- 02A firm sale agreement is what turns an overlap into a bridge. A listing alone doesn't give a lender anything to underwrite against.
- 03The take-out mortgage's terms don't depend on how the bridge resolves. Keeping them separate meant nothing about the new build's financing had to be renegotiated.
- 04Size the peak draw to the project's schedule, not to convenience. A smaller peak balance during the overlap keeps the interim carrying cost proportionate to what the build actually needs.
- 05Ratio math still runs during a bridge, even without a regulatory ceiling. This file is uninsured, so 44% is a comfort convention, not a pass/fail line — but the lender still wanted to see where the number was headed.
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:
- ▸4.10% / 5.85% / 4.75% rates — rates move daily; none of these are quotes.
- ▸the 44% comfort reference during the overlap — this file is uninsured, so there is no CMHC ratio ceiling -- the number is a lender comfort convention, 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.