What Cash Flow Measures, and What It Leaves Out

Cash flow measures money in against money out over a period you chose, which makes any cash-flow figure a claim about what was counted — and the interesting part of the claim is almost always the part that was left out.

The measurement, stated plainly

Cash flow is an arithmetic of timing. It asks what arrived in the account during a period and what left it during the same period, and it reports the difference. That is all it does.

It is not a measure of what the building is worth, of the equity in it, or of what your capital is earning. Return arithmetic answers that second question — the ratios, the numerator and denominator conventions, what counts as invested capital — and it belongs to a different page. Cash flow answers a narrower and more immediate worry: whether the account survives the period. The two questions are both worth asking and they are not the same question.

One more boundary, because it is where counts most often go wrong: this is a count of the bank account, not of a tax return. Non-cash items sit on a different statement and get treated under rules of their own, and how any line is handled for tax is a question for your CPA rather than for this page.

The number that decides whether you can hold on

Small rental buildings are rarely lost because the return was mediocre. They are lost because a cash demand arrived in a period when there was nothing to meet it with, and the owner had to sell, refinance badly, or defer something that then got worse.

That makes cash flow a measure of endurance more than of performance. It is the number an owner actually lives with, checked against a bank balance rather than against a projection, and it is the one that determines whether a building can be carried through a bad quarter and out the other side. A building that clears every period comfortably gives its owner the option to wait. A building that clears every period by a hair gives its owner no options at all, and the first unplanned event converts a paper success into a forced decision.

The costs that fall out of the count

Here is where the honesty lives. Five categories go missing from most cash-flow figures, and they go missing in a recognisable pattern: each one is either irregular, or invisible, or both.

Capital reserves. Every building carries components that will certainly fail — a roof covering, a heating plant, a water heater, a service panel, a sewer lateral, windows, a driveway. Each has a service life that is knowable as a range and unknowable as a date. A count with no reserve line is not a count of a building with no roof cost. It is a count that has quietly moved the roof cost into a future period and stopped looking at it. The failure is not the omission of a number; it is the omission of the line.

Vacancy between tenancies. Rent is not collected in the stretch between one tenant leaving and the next one paying. A count built on a full rent roll is a count of the best available period, presented as though it were every period.

Turnover. The gap itself has costs attached to it — cleaning, paint, flooring, re-keying, the time and money spent advertising the unit, and the days it takes to screen properly rather than quickly. Turnover is where vacancy stops being an absence of income and starts being an expense as well.

Management. Somebody runs the building. If that is a firm, there is an invoice and the line usually survives into the count. If it is you, there is no invoice, and the line usually does not. Carrying your own hours at nothing is a decision to be paid nothing for them, and it conceals the cost right up until the day you stop doing the work.

Insurance beyond the premium. The premium is the smooth part, and smooth costs get counted. What follows is the part that does not.

What the premium counts and the deductible does not

A premium is a recurring, predictable, budgetable line, and for that reason it survives almost every count. The deductible is the opposite in every respect, and it is missing from almost all of them.

A deductible is a cash event. It leaves the account, in full, on the occasion of a loss — and a loss does not land in a quiet period. It lands in the period that already has an emergency repair, a tenant who needs somewhere to be, a unit that cannot be let, and an owner spending time on the building instead of on anything else. The deductible arrives precisely when the account is least able to absorb it. That is not bad luck; it is structural, because the deductible and the disruption have the same cause.

Two policy questions follow from that, and both belong in the count rather than in the surprise. The first is what the deductible actually is on the building you own, which is a line on your own declarations page and takes a minute to read. The second is whether the policy replaces the rent you cannot collect while the unit is out of service — loss of rents is the coverage that answers it, and what an empty unit changes in your policy covers what happens to the rest of the cover during that stretch. Property coverage is the third line to read before you need it, and what actually sets the price of landlord insurance explains why the premium line looks the way it does.

A month is not a year

The period you choose is part of the claim you are making, and choosing it quietly is one way a figure gets flattering.

A building can be positive in eleven periods and lose the year in the twelfth. That is not an unusual outcome; it is the normal shape of a small rental building, because the recurring costs are monthly and the large ones are not. An annual count is the one that catches the irregular items, because a year is long enough for at least some of them to land inside it. A monthly count is the one that tells you whether you can fund the bad period on the day it arrives. Neither replaces the other, and quoting one while thinking about the other is the most common way owners end up surprised by their own building.

Real-World Scenario: Two owners describe the same duplex on the same evening. The first says it clears every month and has done for two years, which is true. The second says it lost money last year, which is also true. The difference is that the second owner counted the period when the water heater went, the lower unit sat empty for a stretch after the tenant left, and the turnover work ran longer than planned — and the first owner counted the other periods. Neither is lying. Only one of them has a figure that tells them what the building will do next time.

What a lender is measuring, and what you are

A lender also computes a cash-flow figure on the building, and it is not your figure. It is built to size credit, so it uses standardized conventions: defined income documentation, factors applied for vacancy and management whether or not those match your arrangements, and a coverage test against the debt over a period the lender chooses.

That figure is produced once, at underwriting, for the purpose of deciding whether the loan is safe. Yours is produced every period, for the purpose of deciding whether you are. The lender is generally indifferent to your unpaid hours, to whether your reserve line is adequate for a building of this vintage, and to what a deductible would do to you in a bad period, because none of those threaten the loan first. Treat a lender’s figure as evidence that a third party ran an independent check, which is genuinely useful. Do not treat it as your count.

When the two questions disagree

A building that cash-flows and a building that returns well are frequently not the same building, and when they conflict the resolution is a sequence rather than a compromise.

Lower leverage tends to produce a comfortable monthly picture and a modest return on the capital tied up in it. Higher leverage tends to produce the reverse — a return that looks strong on paper alongside a monthly position that has no slack in it at all. Both can be reasonable. What is not reasonable is deciding without naming which constraint binds.

The sequence is solvency first. An owner who cannot fund a bad period does not get to collect the return that was projected for the later ones, because they are not holding the building when those periods arrive. So the order of the questions is: can I fund the worst period I can foresee, and only then, is what this capital earns worth the capital being here? A return you cannot survive to receive is not a return.

Running the count yourself

None of the above requires a number from us, and we are not going to supply one. What is worth supplying is the set of instruments you can run against your own building.

Start with the expense categories. The U.S. Census Bureau’s Rental Housing Finance Survey is a survey of rental building owners and their finances; read the categories it collects as a checklist of the lines a serious count carries, not as a benchmark. Schedule E of the federal individual return is the other useful checklist for the same reason — its expense lines are the ones the federal government expects a rental building to have — and read it strictly as a list of categories, because how any line is treated for tax is your CPA’s question rather than this page’s.

For vacancy, the Census Bureau’s Housing Vacancies and Homeownership program publishes the vacancy series and defines its terms, which is what you need in order to decide what a vacancy assumption in your own count even means. For the direction of costs over time, the Bureau of Labor Statistics Consumer Price Index lets you pull the categories that matter to a building — shelter, maintenance and repair, energy — and see how they have moved, rather than assuming this period’s costs are next period’s.

Then run the building’s own instruments. The date on a component’s data plate and the terms of its warranty tell you more about your reserve line than any published table. Your declarations page tells you what the deductible is. The state pages carry what changes from one state to the next. Every one of these instruments produces a current answer rather than a remembered one.

There is a line we do not cross, in writing or on a call. We will not tell you what your cash flow ought to be, whether the figure you arrived at is a healthy one, or whether the building deserves the money. Those are not judgments an insurance agency gets to make for an owner. What we can price is one line inside the count — start a quote, tell us what the building is, and tell us what cover it carries today.