Set aside roughly $800 to $2,500 in cash you can spend the week you get the keys, on top of your down payment, closing costs, and moving budget. This is a different bucket than the "1% of home value per year" maintenance rule you've probably already seen — that's an ongoing annual budget for the life of the house. This is a one-time, move-in-week reserve for the specific, boring, non-optional stuff that shows up in the first few days: re-keying locks, a real cleaning, working smoke and CO detectors, and a check on the systems the seller swore were "fine."

Nobody warns you about this bucket specifically because it doesn't sound dramatic enough to get its own line item. It's not a new roof. It's a locksmith invoice, a cleaning crew, and a plumber poking at a water heater you've never met. Individually cheap. Collectively, a few hundred to a couple thousand dollars you should have sitting in checking before you show up with the U-Haul.

Why this is a separate bucket from the 1% rule

The "budget 1–3% of home value per year for maintenance" rule — the one cited constantly across this site and everywhere else in the industry — is an ongoing number. It's what you should be setting aside monthly, forever, for the roof that'll need replacing in year 12 or the water heater that finally quits in year 9.

The move-in-week reserve is different: it's a short, front-loaded list of things you'll almost certainly pay for in the first 7–14 days, regardless of the home's condition, because you're a new owner and the previous owner's copies of the keys, their choice of cleaning schedule, and their maintenance habits aren't yours. It's closer to a closing cost than a maintenance budget — a known, mostly fixed set of expenses tied to the event of taking ownership, not to how old the house is.

The move-in-week checklist, with real numbers

Here's what typically lands in this bucket, with current cost ranges (as of August 2026):

  • Re-key the locks: $95–$270. HomeGuide puts per-lock rekeying at $15–$40 plus a trip fee, or roughly $95–$270 to rekey a typical three-door house (front, back, garage entry). You have no idea how many copies of the old keys exist — the previous owner's contractor, dog walker, ex-roommate, or that one neighbor who "just watches the place sometimes." Rekeying is cheaper than replacing the locks entirely and solves the actual problem: unknown people having a working key to your house.
  • A real deep clean: $180–$575. Angi puts the national average around $260, with most 1,500–2,500 sq ft homes running $245–$575 depending on scope. A standard move-out clean from the seller (if you even get one) is not the same as a deep clean — grout, baseboards, inside appliances, vents. Worth it even if the house "looked clean" at the final walkthrough, which was staged and lit for exactly that impression.
  • Smoke and CO detectors: $50–$600+. Swapping detector units yourself runs roughly $10–$50 per device — cheap, and arguably the single highest-value thing on this list, since you don't actually know how old the existing units are or whether they still work. If you want them professionally installed or hardwired, HomeGuide puts full installed cost at $110–$410+ per unit, or roughly $550–$1,450 for a full 5-detector single-family home if an electrician's doing hardwired work. Most buyers land at the low end here — buy new units, put them in yourself, keep the receipts.
  • Water heater flush/inspection: $110–$250. Angi puts a standard tank flush around $110–$200 (tankless runs $150–$250). Sediment builds up over years and nobody flushes a water heater right before selling a house — this isn't optional maintenance so much as catching up on someone else's neglect, and it's a lot cheaper than diagnosing a failure six months in.
  • HVAC filter change and tune-up: $70–$200. HomeGuide puts a standard tune-up/inspection visit at $70–$200. Swap the filter regardless (a $15–$30 DIY job) and consider paying for the full visit — it's the cheapest way to find out if the system the inspector glanced at is actually fine or just quiet for now.
  • Initial pest treatment: $150–$300. HomeGuide puts a first treatment/inspection at $150–$300, with ongoing quarterly service around $100–$300 per visit if you keep it going. Even homes that look spotless can have activity the sellers never mentioned (or never noticed) — ants, spiders, or something worse depending on your climate.

Add those up at the low end and you're around $675; at the higher end, closer to $2,300 — hence the $800–$2,500 range up top. Your actual number depends on how much of this you DIY versus hire out, and whether your local labor market runs above or below these national figures.

The stuff the inspection flagged but nobody fixed

Somewhere in your inspection report is a list of minor issues that didn't make it into repair negotiations — because they were too small to fight over, the seller refused, or you were in a competitive offer and didn't want to push. A loose deck railing. A GFCI outlet that doesn't reset. A door that doesn't latch right. None of it is a big deal individually, and all of it is real money if you hire someone to fix six small things separately instead of budgeting for them as one line item now. Pull your inspection report back out before move-in and make an actual list — most of it is a Saturday and a couple hundred dollars in materials, not a crisis, but it needs to be planned for, not discovered.

Why "everything's fine" doesn't mean what you think it means

Big-ticket systems fail in clusters, not randomly. HVAC systems typically last 12–25 years depending on the component, tank water heaters 8–12 years, and roofs 15–30 years depending on material. If a seller tells you a system is "fine," they usually mean it hasn't failed yet — not that it's young. A furnace that's 14 years old and working perfectly today is still a furnace that's 14 years old, and it doesn't reset its clock because it changed owners.

This matches what actual buyers report: it's common to need a major system repair or appliance replacement within the first three to six months of ownership, even when everything worked fine right up through closing, because sellers have zero incentive to replace something that's still limping along on their watch. Ask for the age and service history of the HVAC, water heater, and roof before you close — not to kill the deal, but to know whether you're buying a house where those systems have 15 years of life left or 18 months.

Putting it together

This move-in-week reserve is one piece of a bigger picture. On top of your down payment, add: closing costs (2–5% of purchase price), moving costs, this $800–$2,500 move-in-week bucket, your ongoing 1–3%-of-home-value annual maintenance budget, and a genuinely separate emergency fund. They're not the same pool of money, and treating them as one number is how people end up "surprised" by expenses that were entirely predictable — just not itemized.

Sources

Note: the combined "$800–$2,500 move-in-week reserve" range is this site's own synthesis of the individual service costs above, not a single published figure from any one source — that total is our own transparent calculation.