Rental Capex Is a Calendar Problem, Not a Percentage

A flame sensor costs $14.98 in September and can cost you a tenant in January. Here is how to model rental property capex as a seasonal schedule.

Re:InvestorHub Team · · Deal Analysis

Rental property capex, short for capital expenditures, is the money you spend replacing the long-lived systems in a building: furnaces, water heaters, roofs, appliances. Most models carry it as one flat line, usually a percentage of rent. The flat line gets the annual total roughly right and the timing completely wrong. A flame sensor that costs $14.98 as a retail part in September becomes a service call in November, and if the failure ends a tenancy in January, it becomes the cost of a full turn. This piece covers where capex sits on the calendar, because that is the part your spreadsheet is not showing you.

What does a flat capex percentage hide?

A percentage-of-rent line assumes the money leaves your account in twelve equal slices. Real spending does not behave that way. Heating components do their hardest work from the first cold snap, so failures surface when demand arrives, and that is also when every other landlord in your market is calling the same contractors. A single failure carries three separate costs, and a flat percentage blends them into nothing.

Look at what the numbers say. The repair is $150 to $250 whether you schedule it or not, so the repair is not where the money is. The money is in whether a no-heat failure costs you the tenant. Local rules on heat and habitability vary, so ask a local attorney what your lease and your city require.

Which capex items belong on a September schedule?

This is an underwriting question, not a repair tutorial. The useful split is by when the cash moves, and there are three buckets.

A 12-year-old tank water heater sits inside that six to 15 year window, which is exactly why it belongs on a schedule and not in a surprise. You do not know which winter it fails, but you know it is inside the window, so you fund it.

What does one deal look like with a seasonal schedule?

Here is a worked example, with assumptions you should replace with your own. A single-family rental collects $1,800 a month, or $21,600 a year. The standard flat reserve of 5 percent of rent is $1,080 a year. Now rebuild it as a schedule, assuming the water heater is 11 years old and you plan to replace it at 14, and you plan to replace the furnace in eight years.

The schedule totals $1,451 a year, or 6.7 percent of rent, against $1,080 for the flat 5 percent. The flat line underfunds this house by $371 a year. At a 7 percent cap rate, which is net operating income (NOI) divided by value, $371 of NOI is $5,300 of value. If you finance with a debt service coverage ratio (DSCR) loan, the lower NOI also trims your coverage, which is the same mechanism the insurance inflation piece walks through for rising expenses.

What is one avoided non-renewal worth?

Put the survey average of $3,872 per turn next to the schedule. It equals 2.7 times the entire $1,451 annual capex schedule, and 3.6 years of the flat $1,080 reserve. Against the $150 September check alone, it is 25.8 to 1. That means the check pays for itself if it prevents one tenant loss in about 26 years of checks. Your own turn cost is different, so rerun the ratio with your number. The point survives any reasonable figure: a failure that ends a tenancy costs far more than the schedule that prevents it.

Be honest about what the check does not do. It does not prevent every failure, and an old furnace can still quit in January after a clean September inspection. What it changes is the order of events, so the failures you can predict get found when parts are available, contractors answer the phone, and the call is not a surcharge.

How does this fit with the rest of your underwriting?

This piece owns operating capex timing, and it sits between two articles that own the neighboring lines. The 18 percent rule covers the construction budget you build before you close, including contingency for work in progress. The insurance inflation article covers how a recurring expense grows year over year. Neither one addresses when a replacement dollar leaves your account during the year you operate, which is the gap this one fills.

For the line-item side, the 1 percent rule article sets capex reserves by system age. Use that to decide how much each system needs, and use this one to decide which month it gets paid. If you also carry a vacancy assumption, remember a heat failure feeds it directly, so check how to underwrite vacancy against the same winter.

What should you change on your next deal?

Replace the flat capex percentage with four lines: a September check, a water heater fund, a furnace fund, and a winter cash reserve. Date each one. Run the deal both ways and keep the lower cash flow, because the schedule is the version that matches how the money actually leaves. Then put the September check on your calendar for every door you own, before the first cold snap and not after it.