Two years ago I almost bought a tenth rental property without noticing that one of my existing nine was quietly bleeding money. That building had racked up 890,000 yen in repairs over eighteen months u2014 nearly three times what any of my other properties cost me in the same stretch u2014 and I only caught it because I finally sat down and split my repair spreadsheet by address instead of lumping everything into one general expenses column.
If you own more than one rental, tracking repair costs per property is not optional bookkeeping. It is the earliest warning system you have for a building that is turning into a money pit.
Why Lumping Repairs Together Hides the Problem
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For my first six years as a landlord, I kept one running total for repair costs across all my properties. It felt efficient u2014 one spreadsheet, one number to check every month. The problem is that a single bad year on one property gets absorbed into the average, so a building that needs 600,000 yen thrown at it can hide inside a total that still looks reasonable across nine units. I did not separate the numbers by address until my accountant asked a simple question I could not answer: which property is actually costing you money? That question cost me a weekend rebuilding three years of receipts from memory and old bank statements.
The Spreadsheet Structure I Actually Use
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I keep it deliberately low-tech u2014 a single Excel file with one tab per property, plus a summary tab that pulls totals automatically. Each row logs five things: date, vendor, category (plumbing, electrical, exterior, appliance, other), amount in yen, and whether it was a scheduled maintenance item or an unplanned failure. That last column matters more than people expect. A property with 200,000 yen a year in planned maintenance is healthy. A property with 200,000 yen a year in unplanned failures is telling you something is wearing out faster than it should.
- Date and vendor name, so I can spot the same contractor billing multiple properties for similar issues
- Category tag: plumbing, electrical, exterior, appliance, structural, or other
- Amount in yen, always the final invoiced total, not the estimate
- Planned versus unplanned flag
- A one-line note on root cause when I know it
Updating it takes about five minutes per invoice, and I do it the same day I pay, not in a monthly batch. When I let it slide for a month, I lose the details that make the notes column useful later.
Setting a Per-Property Baseline
Once you have twelve months of data per property, you can calculate a baseline: total repair spend divided by total rental income for that unit. Across my nine properties, that ratio runs between 4% and 9% in a normal year. Anything creeping past 12% for two years running is my signal to stop treating repairs as one-off bad luck and start asking whether the building itself is the problem u2014 old plumbing, a roof near the end of its life, or a structure that was undermaintained before I bought it.
One of my properties, a wood-frame unit built in 1987, sat at 8% for its first four years under my ownership, then jumped to 15% the year the water heater, a section of exterior siding, and the kitchen faucet all failed within five months of each other. Looking at three properties together, that pattern was obvious. Looking at a combined total, it would have been invisible.
Spotting a Money Pit Before It Drains You
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A money pit does not usually announce itself with one huge bill. It shows up as a string of smaller ones u2014 three or four repairs a year that individually look like normal wear but together tell a different story. I now review each property’s rolling twelve-month total every quarter, and I flag anything where the unplanned-repair category has hit three or more incidents. That threshold is not scientific; it is just the point where, in my experience, a single mechanical or structural issue is usually causing a cascade of smaller failures elsewhere in the building.
The property I mentioned earlier eventually needed a full plumbing stack replacement at 620,000 yen. Because I had tracked the smaller failures leading up to it u2014 two leaks and a water pressure complaint over ten months u2014 I was not shocked by the bill and had already budgeted for it out of that property’s own reserve fund rather than pulling from the general one.
What I Did With the Numbers
Tracking costs by property changed two decisions directly. First, I raised rent by 5,000 yen a month on the unit with the worst ratio, specifically to build a repair reserve instead of treating every bill as an emergency expense. Second, I sold a different property outright after three straight years above a 14% repair-to-income ratio u2014 the numbers made it clear that no amount of patching was going to fix a foundation issue cheaply, and continuing to own it meant funding someone else’s future renovation. Without the per-property data, that would have felt like guesswork instead of a decision backed by three years of receipts. It also changed how I screen potential purchases now u2014 before making an offer on any new building, I ask the seller for at least two years of itemized repair invoices, and I have walked away from three deals in the past year purely because those numbers did not add up.
That’s the approach I use across all nine of my properties now, and it’s the first thing I check before I even think about buying a tenth.
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15 years of landlord experience u00b7 3 apartment buildings u00b7 DIY renovations that saved millions of yen. Browse all articles at diytosan.com
