In your first month in a house you just bought, write down seven things:

What each breaker controls.
The make, model, and serial number of every major system and appliance.
The sizes of the parts you will buy again — filters, belts, batteries.
When each system was last serviced, and who did it.
Where the water, gas, and electrical shutoffs are.
The manufacture date on every smoke and carbon monoxide alarm.
Whatever the seller told you out loud during the walkthrough.

Paint, furniture, and the boxes in the garage can wait. This list cannot, because every item on it gets harder to recover the longer you live there. The people who knew the answers have moved out, and the receipts they kept went with them.

You bought the building, not the knowledge

A house transfers on paper. What it does not transfer is the decade of operating detail the last owner accumulated: that the upstairs bathroom outlet is on the hallway circuit, that the furnace was serviced every October by the same company, that the dishwasher was replaced four years ago and the old one is still sitting in the crawlspace.

The seller’s disclosure does not cover this. Disclosure requirements vary by state, and they cover material defects the seller knew about — not the operational detail that makes a house easy to maintain. The inspection report is closer, and worth rereading in month one rather than filing, but it is a snapshot of condition on one day. It does not tell you what the maintenance rhythm was.

So the first month’s job is not repairs. It is recording. Here is what each item takes.

1. Map the breaker panel

Most panels in a resold home are labeled badly, partially, or not at all, and the labels that do exist may predate a renovation. Assume nothing on the panel door is true until you have tested it.

The test itself is simple. Turn on lights everywhere, plug a lamp or a radio into unswitched outlets, then flip one breaker off and walk the whole house writing down everything that lost power. Mapping an unlabeled panel covers the full process, including the breakers that seem to control nothing, and how to label your electrical panel covers writing labels a stranger could use. The free panel label generator prints a directory that fits inside the panel door.

Operate the breaker handles only. Do not remove the panel cover, and if you see heat, rust, damage, or scorch marks, stop and call an electrician — an inherited panel is exactly where a previous owner’s shortcut tends to surface.

Mark what you have not verified as unverified. A new owner’s panel map is mostly guesses in week one, and guesses recorded as facts are worse than blanks.

2. Photograph every data plate

Every major system and appliance has a plate, sticker, or engraved panel with its make, model, and serial number. The furnace and air handler, the water heater, the outdoor condenser, the range, the dishwasher, the washer and dryer, the garage door opener, the sump pump, the water softener.

Photograph all of them now, while you are still walking the house with fresh eyes. Model and serial numbers are what every future search, part order, warranty claim, and service call needs first, and they are always printed somewhere inconvenient — behind the machine, under the lid, on the back of the door.

Many manufacturers encode the build date in the serial number, so those photos often tell you roughly how old each system is. The encoding differs by brand, so look up the format for yours rather than assuming a pattern.

3. Record the sizes before you need them

The parts you will replace on a schedule have sizes, and reading them off the old part is easy while the old part is still installed.

Furnace and air handler filter dimensions, printed on the frame of the filter already in place.
Refrigerator water filter model.
Range hood filter or charcoal cartridge.
Humidifier pad, if there is a whole-house humidifier.
Smoke and CO alarm battery type.
Garage door opener remote battery.

Ten minutes of reading labels now removes a trip to the store later, every time.

4. Reconstruct the service history

You will not get a complete history, but you can usually get more than nothing.

Ask the seller’s agent whether the seller kept service records; sometimes they exist and nobody thought to pass them on. Check inside cabinet doors, the furnace closet, and the water heater — service technicians often leave a dated sticker on the equipment itself. Look for a permit history at your local building department, which will show the work that was inspected: a re-roof, a panel upgrade, an added circuit, a water heater replacement.

Write down whatever you find, dated, with the company name if you have it. A furnace with an October sticker from a named company tells you two useful things: the system has been maintained, and there is a contractor who has already been inside it.

Then start your own history from day one. Every time someone works on the house — you, a plumber, an HVAC technician — record what was done, when, and who did it. That record is worth more each year it exists, and it is the thing the next owner will wish you had kept.

5. Find the shutoffs before an emergency

Locate and label the main water shutoff, the individual fixture shutoffs under sinks and behind toilets, the water heater’s shutoff, the main gas valve, and the main breaker. Test that the water valves actually turn; a valve that has not moved in fifteen years sometimes will not.

If you shut off gas at the meter, have the utility or a qualified professional restore service rather than relighting appliances yourself.

The point of doing this in month one is that the day you need a shutoff, you will be standing in water, and searching is not a plan.

6. Check the age of the alarms

Every smoke alarm has a manufacture date printed on the back of the unit. The NFPA says smoke alarms should be replaced 10 years from that date, regardless of whether they still respond to the test button. Carbon monoxide alarms have a shorter service life that varies by manufacturer — check the unit and its documentation.

Pull each one down, read the date, and write it on your list. In a house that changed hands, alarms installed at the same time will expire at the same time, so knowing the dates now means replacing them on a schedule rather than after one starts chirping at 3 a.m.

7. Write down what the seller said out loud

Somewhere in the walkthrough or the closing, somebody mentions the thing that is not in any document. The disposal jams if you run it without water. The back gate latch sticks in winter. The guy who did the deck is still local. The upstairs radiator needs bleeding every fall.

That information has a short shelf life in your memory. Write it down the same day. It is the closest thing to the previous owner’s operating manual you will ever get.

Turn the list into a schedule

A list of facts is where this starts, not where it ends. Once you know the furnace filter size, the useful next step is a recurring reminder to change it. Once you know the water heater’s age, the useful next step is an annual check on your calendar rather than a memory of having read something about it.

That is what Tobi’s maintenance log does with the list. Each thing in your home becomes a record — furnace, water heater, gutters — with the tasks it needs attached to it, either recurring on an interval or scheduled once. Completing a recurring task recalculates the next due date. Every completion is appended permanently with the date, who did the work, and notes, so the service history you just reconstructed keeps growing instead of going stale. The contractors you find in year one become records too, and their work stays attributed to them.

The panel schedule handles the first item on the list the same way. It mirrors your panel slot by slot, and every circuit carries a flag: verified, a guess, or known wrong. A panel you inherited starts out mostly guesses, and it gets more trustworthy one confirmed circuit at a time.

Put it where the rest of the house can reach it

The failure mode for all of this is a notes app on one person’s phone. That is how the knowledge ended up concentrated in one head in the first place, and buying a house is the moment to not repeat it. If two people live there, both should be able to answer what breaker feeds the garage and when the furnace was last serviced.

A shared household means one record everyone can see and edit from their own phone, syncing in real time. One subscription covers the household, and only the owner pays, so inviting the people you live with costs nothing extra.

Common questions

How long does the first-month list actually take?

The panel mapping is the long one, usually an afternoon. The data plate photos, the part sizes, the shutoffs, and the alarm dates are a couple of hours combined if you do them in one pass through the house. The service history is the piece that trickles in over weeks, as records surface and contractors get called.

What if the house is brand new?

A new build hands you more paperwork, and you still have to consolidate it. The model numbers are in the packet, the panel should be labeled, and the systems are all the same age. Record it anyway, because year one of a new house is the easiest possible time to build a complete history and the paperwork packet is not a schedule.

Which of the seven is most urgent?

The shutoffs and the alarm dates, because both are about the day something goes wrong. The panel is the largest job and the one that pays back longest.

What can wait

Not everything belongs in month one. Cosmetic work, the yard, and the renovation you already have opinions about will all still be there in six months, and none of them get harder to do because you waited. Recording what you inherited is the opposite: the seller’s phone number goes stale, the sticker on the furnace peels, and the memory of the walkthrough fades within a week.

Do the recording first. Then the house is yours in the way that matters — you know how it works.

New homeowner checklist: what the previous owner never wrote down