Most landlords track rent, mortgage, taxes, and insurance — then treat repairs as a surprise. That works right up until a $6,000 roof, a $1,400 water heater, and an $800 furnace repair land in the same twelve months. A property that cash-flowed $250 a month on paper just wiped out two years of profit. The fix is not luck. It is a reserve fund sized to the actual wear on your building.

Reserves fall into two buckets that get confused constantly. Repair reserves cover routine breakdowns — a leaking faucet, a tripped GFCI, a broken garbage disposal. Capital expenditure reserves (CapEx) cover big-ticket items that wear out on a predictable schedule: roof, HVAC, water heater, flooring, appliances, exterior paint. Ignore either one and your "profit" is a mirage you are borrowing against.

Why Percentage Rules Fail on Their Own

You have probably heard the shortcuts: set aside 1% of property value per year for maintenance, or use the 50% rule where half of rent goes to expenses. These are fine for a napkin screen on a deal you are considering. They are terrible for actually funding a specific property.

A 1965 house with a 22-year-old roof and original galvanized plumbing does not wear like a 2015 build, even if both are worth $300,000. The 1% rule tells you to reserve $250 a month for both. The old house needs closer to double that; the new one, less. Percentage rules average away the exact information you need. Use them to sanity-check, then build the real number component by component.

A reserve number that ignores the age of your systems is a guess wearing a formula's clothing.

The Component Method: Build Your Number From Parts

The honest way to size CapEx is to list every major system, estimate its replacement cost, estimate its remaining life, and divide. The result is what you should be setting aside monthly for that component. Here are typical figures for a single-family rental or small multifamily unit — adjust for your market and finishes:

  • Roof — $8,000 replacement, ~25-year life = $27/month. If yours is already 18 years old, you have 7 years to save $8,000, so reserve $95/month.
  • HVAC / furnace — $5,500 replacement, ~18-year life = $25/month.
  • Water heater — $1,400 replacement, ~10-year life = $12/month.
  • Flooring — $4,000, replaced roughly every 8–10 years in a rental = $37/month.
  • Appliances — $2,500 for the set, ~12-year life = $17/month.
  • Exterior paint / siding — $6,000, ~12-year cycle = $42/month.
  • Plumbing & electrical events — budget a flat $30–$50/month; these are lumpy and hard to schedule.

Add those up and a typical older single-family rental lands somewhere around $180–$280 per month in true CapEx — before routine repairs. That is real money most pro-forma spreadsheets quietly leave out. The number is not meant to be paid every month; it is meant to be banked every month so the cash exists when the component fails.

Don't Forget Routine Repairs and Turnover

CapEx is the planned wear. On top of it, budget for the unplanned: a $150 plumber visit, a $90 appliance part, a $200 pest treatment. For a property in decent shape, reserving $75–$150 per month for routine repairs is reasonable; older properties run higher.

Turnover is its own line. Every time a tenant leaves you face some mix of cleaning, paint touch-up, carpet cleaning or replacement, and small fixes. A light turn might cost $400; a full turn with new paint and flooring can hit $2,500. If your average tenant stays three years, amortize an expected $1,800 turn over 36 months and you are reserving $50/month for turnover alone. This is exactly why reducing tenant turnover protects your margins — every avoided move-out is a turn cost you never pay.

Ready to put this into practice? Download KeyLoft for Free — it’s free and works offline.

Where the Money Should Actually Live

A reserve fund only works if it is real cash you will not accidentally spend. A few rules that keep it honest:

  • Separate account — keep reserves in a distinct high-yield savings account per property or per portfolio, not commingled with your operating checking. Money you can see is money you will rationalize spending.
  • Fund it first — treat the monthly reserve transfer like the mortgage: automatic, on the same day rent clears, before you count anything as profit.
  • Set a floor — many landlords target a minimum of $3,000–$5,000 per unit in liquid reserves plus 3–6 months of that unit's operating costs. Below the floor, you pause distributions until you rebuild.
  • Track draws against components — when you replace the water heater, log it against the water-heater line and reset its clock. Otherwise you lose the thread on what is funded and what is overdue.

Tracking this by hand across a few properties gets messy fast. Logging each system's age, last service date, and reserve balance in one place is exactly the kind of record-keeping tools like KeyLoft handle well — you can note the install date of a roof or HVAC unit and keep repair history attached to the property, offline, without a spreadsheet you forget to update.

Adjust the Numbers to Your Property

The component figures above are starting points. Three factors move them the most:

  • Age of systems — a component past 70% of its expected life needs an accelerated reserve, because you are saving against a short runway.
  • Climate — hard freezes, coastal salt air, intense sun, and heavy snow load all shorten roof, paint, and HVAC life. A Phoenix AC unit works harder than a Portland one.
  • Finish level and tenant type — higher-end finishes cost more to replace; higher-turnover tenant profiles wear flooring and paint faster.
Reserve for the property you own today, not the brochure version. The roof does not care what the pro-forma said.

Reassess once a year. Walk the property, update each component's age, and recalculate. A ten-minute annual review beats a five-figure surprise. This is the same discipline that separates a hobby from a business — the freelancers and sole proprietors who use Stintly to set aside taxes and smooth irregular income are running the exact same play: fund the known-but-lumpy expense before it arrives, not after.

When You Hire Out the Big Jobs

CapEx items are where you meet contractors, and contractor costs are where reserve math lives or dies. Get itemized bids, not lump sums — a roof quote should separate tear-off, decking, underlayment, materials, and labor so you can see what you are paying for and compare apples to apples. Keep every invoice; capital improvements affect your cost basis and depreciation at tax time, which routine repairs do not.

If you manage or GC larger renovation projects — a full unit rehab, an addition, a multi-trade turn — that crosses from simple repair logging into real project management, with job costing and contractor billing to track. That is a different tool than a landlord app; something like TrestleBook is built for construction job costing and contractor invoicing, while a landlord tool keeps the ongoing property record. Use the right one for the scale of the job.

A Simple System You Can Start This Month

You do not need a perfect model to be far ahead of most landlords. Do this:

  1. List your major systems and their approximate ages — roof, HVAC, water heater, flooring, appliances, exterior.
  2. Estimate replacement cost and remaining life for each, then divide to get a monthly reserve per component.
  3. Add routine repair and turnover lines on top.
  4. Open a separate reserve account and automate the transfer the day rent clears.
  5. Log every draw and reset the component's clock when you replace something.
  6. Review annually and adjust for age and any big changes.

Do this and the roof that fails in year seven is a scheduled event you already funded, not a crisis that empties your checking account. The landlords who last are not the ones who never have expensive repairs — every property eventually needs a roof. They are the ones who saw it coming and had the cash waiting. Size your reserves to the building you actually own, fund them first, and your cash flow stops lying to you.