The client
A homeowner in Vernon is building a legal fourplex on a lot newly permitted under BC's small-scale multi-unit housing rules, financed through a construction mortgage at a total cost of $780,000.
Total construction cost
$780,000
Four-unit structure
Household's own value estimate
$900,000
Based on nearby rents, not an appraisal
Appraiser's cost-approach value
$810,000
No comparable sales existed for this housing type
Lender's maximum advance
80% of the appraised value
This lender's own construction policy
The problem
The lot had always been zoned single-family, until BC's 2023 provincial small-scale multi-unit housing law overrode that zoning and permitted up to four units on it. The household priced their build against what they assumed a finished fourplex would be worth in Vernon's market -- but no comparable sales exist yet for this newly-legal housing form, and the appraisal itself had to be built a different way.
Why the appraisal came in under the market assumption
- ▸A comparable-sales approach needs actual recent sales of similar properties -- and this housing type is too new in Vernon to have any
- ▸Without comparables, the appraiser valued the as-complete property by the cost approach: what it costs to build, plus a modest built-in allowance, not what a buyer might eventually pay
- ▸The lender's construction-underwriting policy advances against the lower of cost and appraised value -- and here, the cost-approach appraisal was lower than the household's own market assumption
This is a timing problem specific to a genuinely new housing type, not a defect in the build itself -- once enough fourplexes actually sell in Vernon under this zoning, a comparable-sales approach will likely become available for the next file.
The numbers
The gap was real and had to be covered in cash -- there was no ratio or income problem to fix, only an appraisal-methodology ceiling.
| The final draw, at the lender's 80% maximum | Amount |
|---|---|
| Household's own market-value estimate | $900,000 |
| Maximum draw at 80% of that estimate | $720,000 |
| Appraiser's cost-approach value | $810,000 |
| Maximum draw actually supported, at 80% | $648,000 |
| Cash gap the household had to cover | $72,000 |
The construction cost itself, $780,000, sat comfortably under even the cost-approach value -- the gap was never about whether the build made financial sense, only about which valuation the lender's final advance was measured against, at a time when residential construction investment across Canada is increasingly running into exactly this kind of new-housing-type appraisal gap.
The solution
A submortgage broker, licensed under BC's Registrar of Mortgage Brokers, flagged the appraisal-methodology risk months before the final draw was requested, not after.
First, asked the appraiser directly, early in the build, whether comparable sales existed for a newly-legal fourplex in Vernon. None did -- the zoning change was too recent for any to have sold yet.
Second, confirmed the lender's own policy on advancing against a cost-approach valuation. This lender advances against the lower of cost and appraised value, a materially more conservative position than a comparable-sales appraisal would have supported.
Third, had the household set aside the $72,000 gap in cash well ahead of the final draw. Discovering a shortfall of this size at the last advance, with trades waiting to be paid, is a far worse position than planning for it early.
The outcome
The final draw funded against the $810,000 cost-approach value, with the household's own $72,000 covering the gap from savings. The build completed on schedule, at a lower advance than the market-value assumption would have supported.
Each lender sets its own policy for advancing against a cost-approach valuation versus a comparable-sales one -- an 80% maximum and this particular gap are illustrative of this file and this lender only.
What to take from this file
- 01A brand-new provincial zoning category can outrun the appraisal data that supports it. BC's small-scale multi-unit housing law changed what a lot can hold years before enough sales exist to value it by comparables.
- 02Ask an appraiser about comparable-sales availability before the build starts, not at the final draw. A cost-approach valuation, once it's the only option, is rarely a surprise a household can avoid -- only one they can plan for.
- 03A household's own market-rent-based estimate is not an appraisal. Treat it as a planning number, never as the figure a construction advance will actually be measured against.
- 04Confirm the lender's own cost-vs-value advance policy in writing, early. Not every lender advances against the same, more conservative figure this one did.
- 05Build a cash reserve for exactly this kind of appraisal-methodology gap on a genuinely new housing type. It isn't a sign anything went wrong with the build -- only that the market hasn't caught up to the zoning yet.
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.
- ▸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:
- ▸80% maximum loan-to-value — each lender sets its own completed-construction advance ceiling; this figure is illustrative of this lender's policy only.
- ▸the $900,000 market-value estimate — the household's own estimate, not an appraisal -- shown only to size the gap the cost-approach valuation actually produced.
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.