Treadstone Associates
Case File № 733 · Construction & Land

One unit's use, not the unit count

a Greater Sudbury build reclassified mid-construction

Partway through building a straightforward four-unit residential rental property in Greater Sudbury, the owner decided to lease the ground floor to a retail tenant instead of using it as the fourth residential unit. The construction lender reclassified the entire facility from residential to mixed-use commercial construction financing over that single unit's change of use -- not any change in the building's total unit count.

OntarioUninsured · ConstructionFiled August 9, 20265 min read
$585,000 → $507,000

the construction facility, before and after the ground-floor unit's change of use

$78,000

the gap the owner had to cover before draws could resume

42.8%

total debt service on the completed, reclassified mortgage

Anonymized illustration. The borrowers, dollar figures, and rates in this file are an illustrative composite — no real client is identifiable, and any rate shown is illustrative, not a quote. The rules are real: every regulatory figure is cited to its source in the Sources section, and the math computes exactly as shown.

№ 01

The client

An owner building a $780,000 four-unit residential rental property in Greater Sudbury, approved for a residential construction mortgage at 75% of project cost.

Total project cost

$780,000, Greater Sudbury

Purpose-built four-unit rental property

Original facility

$585,000

75% of project cost, under the residential construction program

Mid-build change

Ground floor leased to a retail tenant

In place of the planned fourth residential unit

Combined household income

$10,600/month

№ 02

The problem

A residential construction mortgage is built around a defined outcome: a building with no commercial component. A single unit's change of use, decided mid-build, is enough to take a project outside that box entirely -- even with the total number of units unchanged.

What actually triggered the reclassification

  • The building's total unit count never changed -- it was designed and remains a four-unit property
  • The owner decided, after the foundation and framing were already in, to lease the ground floor to a retail tenant instead of finishing it as the fourth residential unit
  • The construction lender's residential program is restricted to buildings with no commercial component at all, regardless of how small that component is

Nothing about the building's size changed. What the ground floor would be used for did, and that was enough.

№ 03

The numbers

The number that actually moved was the size of the facility itself, not any ratio on the completed mortgage.

One change of use, two very different facilitiesAmount
Total project cost$780,000
Original residential facility (75% of cost)$585,000
Mixed-use commercial facility (65% of cost)$507,000
Completion mortgageFigure
Facility shortfall to cover before draws resumed$78,000
Qualifying payment (7.45%), 25 years$3,693/mo
Property tax + heat$570
Total debt service, $10,600/mo household income42.8%

42.8% clears comfortably once the facility itself was resized -- the real cost of this file was the $78,000 gap between programs, not anything wrong with the household's own qualifying numbers, in a market where housing starts data shows plenty of small purpose-built rentals moving through construction at once.

№ 04

The solution

A mortgage agent licensed under Ontario's Mortgage Brokerages, Lenders and Administrators Act treated the change of use as a financing-structure decision to plan for immediately, not a detail to disclose after the fact.

First, flagged the change of use to the construction lender the moment the decision was made, rather than letting a site inspection discover a retail buildout partway through a residential draw schedule.

Second, arranged the $78,000 shortfall as additional equity, closing the gap between the original residential facility and the smaller mixed-use commercial facility the reclassification required.

Third, obtained a new appraisal reflecting the ground-floor unit's actual commercial use and moved the remainder of the build onto a mixed-use commercial construction facility with its own revised draw schedule.

Written notice to the construction lender of the ground-floor unit's change of use, given as soon as the decision was made
A new appraisal reflecting the building's actual mixed-use composition
Additional equity to cover the gap between the residential and mixed-use commercial facility sizes
A revised draw schedule under the mixed-use commercial construction program
The retail tenant's own commercial lease, in place before the ground-floor unit's value could be counted
№ 05

The outcome

The build completed and converted to a $507,000 mortgage at 5.45%, with total debt service at 42.8% once the retail unit's own commercial lease was in place.

This facility is uninsured and, once mixed-use, is not tested against a CMHC ratio ceiling; the 42.8% figure is informational.

№ 06

What to take from this file

  • 01A single unit's change of use can reclassify an entire construction facility, independent of the building's total unit count. Five units crossing a threshold is one path to commercial treatment; one unit changing its use is another.
  • 02Flag a mid-build change of use to the lender the moment it's decided, not when a site inspection finds it. A residential construction program's draw schedule assumes the building it originally approved.
  • 03Budget for a smaller facility, not just a delayed one. A mixed-use commercial construction program's own loan-to-cost ceiling can run meaningfully below a residential program's, on the identical project cost.
  • 04A new appraisal reflecting the actual, current use is what lets draws resume. The original residential appraisal no longer describes what is actually being built.

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.

Illustrative in this file — lender-specific, not rules:

  • 5.45% contract rate — rates move daily; not a quote.
  • the 75% / 65% loan-to-cost ceilings — each construction lender sets its own loan-to-cost ceiling for a residential versus a mixed-use commercial facility; there is no published rule.
  • the 42.8% TDS figure — this facility is uninsured and, once mixed-use, is not tested against a CMHC ratio ceiling -- the number is informational.

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.

First published 9 August 2026Rules last verified 9 August 2026Next scheduled review 9 February 2027

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.

Treadstone fulfillment

Files like this are daily work for our desk.

Document collection, ratio math under multiple treatments, lender placement notes, and submission-ready packaging — for Canadian mortgage brokers who would rather be in front of clients.