Four Units and Five Units Are Two Worlds

The step from four units to five is the shortest move in a Canadian residential portfolio and the least understood. Nothing about the buildings has to change. The bricks are the same, the tenants are the same, the street is often the same one. What changes is the question the lender asks, and it changes completely, at a line drawn by convention and held in place by the rules of the institutions that finance the purchase.

Below that line a building is read as a house with extra doors. The lender studies the borrower, which means the pay stubs, the credit history and a ratio computed on a person. At the line and above it, the same lender studies the building: what it earns, what it costs to run, and whether the difference covers the debt. The borrower is still in the file. The borrower is no longer the subject of it, and an investor who learns that during a conditions period learns it expensively.

What actually changes at the line between four units and five?

Almost everything about the financing changes and almost nothing about the property does. At four units and below, a Canadian lender underwrites a residential mortgage on the borrower. At five units and above, the same purchase is underwritten as a commercial file on the building. The appraisal, the documents, the equity, the term and the liability all move with it.

The line is a convention of the lending market and of the insurers standing behind it, and it holds steadily across the country. A fourplex is residential. A five unit building is a commercial multifamily asset, and the two are financed by different departments, on different forms, on different timetables, by people who read different things first.

That is why the step feels larger than it looks on a listing sheet. An investor who has bought three plexes carries a working model of how a purchase goes: the offer, the inspection, the appraisal, the approval, the notary. Every stage of that model survives the crossing in name and changes in substance. The words on the calendar stay. What sits behind each word is new.

How does the lender's question change from can you pay to can it pay?

Below the line the lender asks whether the borrower can carry the payment out of personal income, and tests it with a debt service ratio computed on the person. At and above the line the lender asks whether the building can carry it out of net operating income, and tests that with a coverage ratio computed on the asset.

Net operating income is the figure that does the work. It is the rent the building actually collects, less the cost of operating it: municipal and school taxes, insurance, heat where the owner pays it, management, maintenance and an allowance for vacancy. Financing is excluded, because financing is the thing the number is being asked to support. The underwriter rebuilds that figure from the seller's statements and rarely accepts the seller's version whole.

The coverage ratio then divides that income by the debt service the building would carry. A ratio above one means the building pays its own mortgage with something left over. A ratio at or below one means the owner feeds it. Under the MLI Select programme of the Canada Mortgage and Housing Corporation, and as at 15 September 2026, the minimum coverage ratio is 1.10 for standard rental housing, 1.20 for other shelter models and 1.40 for non residential space.

The borrower does not vanish from that arithmetic. Personal income, net worth and experience still enter the file, as the answer to a second question about who will hold the asset through a bad year. What has changed is the order. The building is examined first, and the borrower is examined afterwards as the person standing behind it.

What changes about the appraisal, and why is that sharpest in Quebec?

A residential appraisal on a plex is built mainly from comparable sales of similar buildings nearby. A commercial multifamily appraisal is built mainly from economic value, which is derived from the income the building produces and the rate a purchaser of income would apply to it. The two methods can reach very different numbers on the same address.

An investor who has only ever bought plexes meets economic value for the first time at exactly the wrong moment, somewhere between an accepted offer and a financing condition. In Quebec the difference bites hardest. Appraisals of multifamily buildings for commercial financing are prepared on economic value as a matter of course, while a market where plexes trade on comparable sales has trained the buyer to expect something else entirely.

The consequence is a gap between the price and the value a lender will finance. Where the rents in place sit below what the units might command, economic value follows the rents in place and ignores the potential. The vendor prices the potential. The appraiser values the collected income. The lender lends against the appraiser's figure, and the buyer covers the difference in cash.

This is one of the ordinary ways a first commercial purchase fails late. Nothing in the building changed and nothing in the offer was careless. The buyer carried a residential intuition across a line where it stops applying, and found out when the report arrived. Reading a commercial appraisal before you need one costs an evening. Reading your first one under a deadline costs a great deal more.

What do the two questions look like on a four unit and a six unit?

Set side by side on invented buildings, the difference is one line of arithmetic. On the four unit the lender asks what the borrower earns. On the six unit the lender asks what the building earns. The figures below are illustrative arithmetic on buildings that do not exist. They are not a quotation, a projection or anyone's actual file.

Take a four unit building at a price of $900,000 with $200,000 down. The lender adds the borrower's salary to a portion of the rent, sets the total against every monthly obligation the borrower already carries, and produces a ratio on the household. If the household passes, the file passes. A weak month at the building is absorbed by a strong salary, and the underwriter counts on exactly that.

Now take a six unit building at a price of $1,500,000. The lender rebuilds the income: say $120,000 collected, $48,000 of operating costs, leaving a net operating income of $72,000. If the debt on offer would cost $60,000 a year, the coverage sits at 1.20. The salary that carried the fourplex never enters that division. The building either covers itself or it does not.

Two things follow from the same pair of numbers. The loan the second building supports is set by its own income, so the amount available is capped by the rent roll and no longer by the borrower's pay. And every dollar of coverage the building lacks has to be replaced by a dollar of equity at closing, which is where the cash requirement comes from.

Why does the cash required rise faster than the price does?

Three forces push in the same direction at once. The loan is sized by the building's income and no longer by the price. The lending ratios available on commercial multifamily are generally tighter than on a residential plex. And the closing costs of a commercial purchase are larger. Together they produce a cash requirement growing faster than the sticker.

Start with the loan itself. On a residential purchase the loan is a percentage of the value and the rest is the down payment. On a commercial purchase the loan is the smaller of two figures: a percentage of value, and the amount the net operating income will cover at the required ratio. Whichever binds first sets the loan, and on many income buildings the coverage test binds first.

Then add the costs that appear only above the line. A commercial appraisal costs several times a residential one. An environmental site assessment and a building condition assessment are ordered on many files. Legal work is longer. Where mortgage loan insurance is used, a premium and an application fee enter the budget. And the building itself asks for a reserve, because six tenancies, one roof and one heating plant produce surprises in the first year that a duplex never produced.

What mortgage loan insurance becomes available at and above the line?

At five units the purchase becomes eligible for the multi unit mortgage loan insurance of the Canada Mortgage and Housing Corporation, which has no application below that size. The published products include Standard Rental Housing, Student Housing, Supportive Housing, Retirement Housing, Single Room Occupancy, Modular Rental Housing Insurance and MLI Select.

The minimum project size is the detail that defines the line. As at 15 September 2026, Standard Rental Housing requires a project with at least five rental units, and Student Housing requires at least five rental units as well. As at 15 September 2026, MLI Select requires a minimum of five units, except retirement homes, where a minimum of 50 units or beds is required.

Mortgage loan insurance never functions as a convenience. It is a second set of rules sitting behind the lender's own, with its own eligibility criteria, its own tests and its own timetable. As at 15 September 2026, MLI Select sets minimum coverage ratios of 1.10 for standard rental housing, 1.20 for other shelter models and 1.40 for non residential space, and a file has to satisfy those alongside whatever the lender requires. The programme rules move, and the corporation's own pages hold the current version.

What paperwork appears that a four unit purchase never asked for?

A commercial file is built from documents about the building, and most of them have no residential equivalent. A rent roll, two or three years of operating statements, the leases themselves, the tax and insurance bills, and on many files an environmental site assessment and a building condition assessment. The borrower's own documents become the smaller half of the package.

The rent roll is the spine of it. It lists each unit, the tenant, the rent, the lease term and the arrears, and an underwriter reads it for what is collected and never for what is posted. A unit advertised at a rent nobody pays is a unit at the rent that is paid. In Quebec the lease and the rent history behind it carry weight, because the rent that travels with the unit is the rent on record.

Operating statements are read the same way, with suspicion applied evenly. An owner who has managed the building personally and paid nothing for it will find a management allowance inserted anyway. An owner who has deferred maintenance for four years will find a maintenance allowance inserted. The underwriter is rebuilding a normalised income, and a seller's spreadsheet is the starting point of that exercise.

The environmental and building condition reports surprise people most. A phase one environmental site assessment looks for contamination risk from current and historic uses, including the buried oil tank and the dry cleaner that occupied the ground floor in 1974. A building condition assessment prices the roof, the envelope and the systems over a stated horizon. Both cost money, both take weeks, and either one can end a transaction.

What changes about the term, the interest structure and the guarantee?

Commercial terms are usually shorter than the amortisation and shorter than residential borrowers expect, so the loan comes up for renewal while a long amortisation is still running. Pricing is quoted against a benchmark and fixed at commitment. And the loan is written to the building, which is why a personal guarantee becomes an explicit term to be negotiated.

The renewal is the exposure that residential experience hides. On a house the renewal is an administrative moment with a rate attached to it. On an income building the renewal is a small underwriting, because the lender looks again at the coverage the building produces at the pricing of the day. A building that covered its debt comfortably under one set of conditions may not cover it under another, and the owner closes the gap.

The guarantee moves from assumed to written. A residential borrower is personally liable and rarely thinks about it. A commercial borrower is often a corporation holding one building, so the lender asks the individuals behind that corporation to guarantee the debt in whole or in part. A guarantee that is full, limited, or reduced once the building performs is a matter of negotiation, and that negotiation happens once, at commitment. The covenants around it bind for the life of the loan, and they are read before they are signed or they are discovered afterwards.

Why do many investors cross the line too early?

Because the arithmetic of the step is invisible from below, and the building looks affordable on price alone. An investor computes a down payment the residential way, finds the number reachable, and buys. The appraisal then arrives on economic value, the coverage test binds the loan, and the cash required turns out materially larger than the plan allowed for.

Some of those purchases close anyway, funded by emptying every account the buyer has. That is the outcome to watch, because the trouble arrives afterwards. Capital goes into the building at closing and cannot come out again until the building supports more debt, and a building bought above its economic value supports more debt only after years of work on the income.

That is what a trapped position looks like from inside. The owner holds real equity on paper and cannot reach it, because a refinance is decided by the same coverage test that limited the original loan. Selling recovers part of it and costs a commission, a prepayment charge and the transfer duties on the way back out. Waiting works, and waiting is measured in years.

None of that argues against crossing. It argues for crossing with the arithmetic done first and with cash that was not scraped together in the final six weeks. The investors who make the step comfortably are usually the ones who spent a year preparing for it, and that preparation is unglamorous and cheap set against the alternative.

What should an investor do in the year before crossing?

Learn the commercial vocabulary before it costs money, and assemble the cash before anyone asks for it. Read a commercial appraisal on a building you are not buying. Build a rent roll and an operating statement for a property you already own. Meet a mortgage broker who writes commercial files. And put the equity somewhere it can be reached.

The cheapest education is on your own portfolio. Take a plex you own, normalise its income the way an underwriter would, insert the management allowance and the vacancy allowance you do not currently pay, and compute a coverage ratio on the debt it carries. The number will be lower than the cash flow you feel each month. That gap is the whole lesson, and it costs an evening.

The relationship is worth building early. A mortgage broker or a commercial lender will tell you what a file needs before you have one, and will look at a listing with you at no charge. A first commercial application is a poor place to discover what the institution wanted, because a commercial application costs real money and real weeks.

And the tax and ownership questions belong to a CPA before the offer, never after it. Buying the building personally or through a corporation changes the financing, the guarantee, the eventual sale and the estate. That decision is difficult to reverse once title is registered, and it is not a question any website can answer for your file.

Where could the equity for that step have been waiting?

Somewhere that was accumulating quietly while the last three purchases were being made, because the step needs materially more cash than the one before it did. A savings account is one place. Equity inside an existing building, reached by refinancing it, is another. And an investor who has been funding a participating whole life insurance contract has one more.

The connection is the equity step and nothing grander. Crossing the line usually calls for a larger contribution than any previous purchase required, that money has to have been accumulating somewhere for years, and a participating contract funded over a long period holds a value the owner may request an advance against without a credit application. How a commercial lender then reads such an advance is dealt with in cash value as the down payment on five units.

The limit belongs in the same breath as the claim. A participating whole life contract is insurance and it is not an investment. Its purpose is a capital sum payable on death, the accumulated value is a contractual feature of that insurance, and participations are declared at the insurer's discretion and are never guaranteed. A contract funded for three years holds a small fraction of what a six unit purchase requires, and no proposal design changes that.

So the honest sequencing runs opposite to the sales version. The contract does not create the equity for a commercial purchase. A contract funded patiently for a decade or more, beside a portfolio that already carries itself, can hold part of what the next step needs, and it is one source among several. Anyone describing it as the route into apartment buildings is describing something that does not happen.

Who this suits, and who it does not

The crossing suits an investor whose existing buildings carry themselves without monthly attention, who has cash assembled and documented before an offer is written, and who has read a commercial appraisal and a rent roll before needing to understand one under a deadline. It suits an owner intending to hold the asset for a decade.

It does not suit an investor buying the step for its own sake. A six unit building bought above its economic value is a worse asset than a fourplex bought sensibly, and the size of a portfolio measures very little on its own. It does not suit an investor with no reserve after closing, because the first year of an income building asks for cash and asks early.

And it does not suit anyone looking for a promise. No page can tell you what a lender will decide, because lenders write their own credit policy, mortgage insurers write their own rules, and underwriting discretion is real. What is described here is a line, what sits on each side of it, and the work that makes the crossing survivable. The wider arrangement beside a portfolio is set out on the real estate investors page.