If you spend an hour on every property that shows up in your inbox, you will burn out within a month and you will not have bought anything. Most listings are not investable. The job of an experienced investor is not to study every property carefully. It is to discard ninety percent of them quickly and study the remaining ten percent thoroughly.

What follows is the filter I use. It takes about ten minutes per property, assumes nothing about the listing being accurate, and produces a clear "no" or "worth a deeper look" by the end. It is not a substitute for due diligence. It is the gate that decides whether due diligence happens at all.

Minute one: the address

Before you read the listing, look up the address on a satellite map. Then drop into street view and walk the block in both directions. You are looking for two things.

First, the neighborhood texture. Are the surrounding houses well maintained? Do you see fresh paint, kept lawns, parked cars in driveways instead of on lawns? Or do you see broken windows, abandoned vehicles, and overgrown lots? The neighborhood within four blocks of your property will determine your tenant pool more than any feature inside the house.

Second, structural context. Is the property next to a busy commercial road? A railway? A power substation? A property abutting any of those will rent for 10 to 20 percent below its comparable peers and will sit vacant longer. None of this appears in the listing.

If the neighborhood does not pass the satellite-and-street-view test, stop here. You have just saved nine minutes.

Minute two to three: the rent reality check

The listing will tell you what the seller hopes the property could rent for. That number is often wishful. You need the real number.

Open Zillow, Apartments.com, and Rentometer. Search for active rental listings within half a mile, in the same bedroom and bathroom count, built within twenty years of your subject property. Look at properties that are currently rented, not aspirational listings sitting at $2,800 for the past four months because they are overpriced.

Take the median of five comparable rents. That is your starting number. Then subtract 5% if the property has any clear disadvantages (older kitchen, single bathroom in a market that expects two, no parking, no in-unit laundry). What you have now is a defensible market rent that an underwriter or a competent property manager would accept.

Minute four: the gross rent multiplier sanity check

The gross rent multiplier is a crude but useful tool. You divide the purchase price by the annual gross rent.

A property listed at $240,000 with a defensible market rent of $1,650 per month has an annual rent of $19,800 and a GRM of 12.1. In strong cash-flow markets in the Midwest and Southeast, you want a GRM under 10. In moderate markets, under 12 is acceptable. Above 14, the property is unlikely to cash flow at current interest rates regardless of how clever your financing structure is.

This single ratio will let you reject most coastal-market listings in under a minute. A $850,000 single-family rental in San Diego renting at $4,200 per month has a GRM of about 16.9. The math on it does not work at any normal financing structure. Investors who buy it are betting purely on appreciation, which is a different game with different rules.

Minute five to six: expenses you will actually have

The listing will rarely tell you property tax, insurance, or expected maintenance honestly. You need to estimate these yourself.

Property tax: most US counties post millage rates and assessed values publicly. For a quick estimate, take 1.0 to 1.3 percent of the purchase price annually as a national-average ballpark. In high-tax states like New Jersey, Illinois, or Texas, use 1.8 to 2.4 percent. In Hawaii or Alabama, you can use 0.5 percent. This will be wrong by a few hundred dollars but right by an order of magnitude.

Insurance: budget $1,200 to $1,800 per year for a single-family rental in most markets, more in Florida and the Gulf Coast, more if there is any wood-frame multifamily. Get a real quote during due diligence, but for the ten-minute filter, use the rule of thumb.

Maintenance and capital reserves: at minimum, set aside 8% of gross rent for routine maintenance and another 5% for capital reserves on a property in good condition. On a property over thirty years old, push those numbers to 12% and 8% respectively. Old houses break in expensive ways that newer houses do not.

Vacancy: 6 to 10 percent of gross rent depending on the market.

Property management: 8 to 10 percent of gross collected rent, even if you are managing the property yourself. Either you pay a professional or you pay yourself, and the value of your time should appear in the model.

Minute seven: the financing assumption

Assume 25% down on a conventional investment property loan, 30-year amortization, at a rate matching today's market. As of mid-2026, that is around 7.0 to 7.25 percent for investment properties. Do not use the rate you see advertised on rate-shopping sites, which usually quote owner-occupied rates.

Calculate the monthly principal and interest payment. A standard amortization formula works, or any free calculator. Then add the monthly property tax (annual divided by 12) and monthly insurance (annual divided by 12) to get your total monthly housing cost.

Minute eight: the cash flow truth

Now build the actual monthly cash flow:

If the cash flow is positive at all, the property is worth a deeper look. If it is negative, you need a specific reason to continue. "It will appreciate" is not a sufficient reason in most markets. "The rent is currently below market by 20% and I can raise it within twelve months" might be, if you can verify it.

The properties that build wealth are rarely the ones that look exciting in the listing. They are the boring ones where the spreadsheet keeps coming out slightly positive month after month.

Minute nine: the cash-on-cash return

Take your annual cash flow (monthly times twelve) and divide it by your total cash invested (down payment plus closing costs plus immediate repairs). Multiply by 100 for a percentage.

In the current environment, a cash-on-cash return below 5% is hard to justify for an investment that requires active management and assumes meaningful illiquidity risk. You can earn close to that on a Treasury with no work and no risk. A 7 to 9 percent cash-on-cash is solid. Anything above 10 is worth investigating closely, because either you found a real opportunity or you have made an arithmetic mistake. Both are common.

Minute ten: the gut check

Read your own analysis like a stranger would. Are any of your numbers suspiciously optimistic? Did you assume a low maintenance reserve because the property is "recently renovated"? Did you assume strong rent because comparable properties on Zillow are listed at high prices, ignoring that listed prices are not transacted prices?

If your model still produces positive cash flow after you have penalized every soft assumption by 10 percent, the property is genuinely worth a deeper analysis. If positive cash flow only survives because of the most optimistic version of each input, the deal is not actually positive. It is a story you have told yourself.

What to do with the survivors

Out of every twenty properties you run through this ten-minute filter, you may have one or two that survive. Those are the properties that get the full treatment: physical visit, professional inspection, contractor walkthrough, lender pre-approval, attorney review. That is where you spend the real hours of your week.

The discipline of fast filtering is what allows the slow, careful work on the right properties to actually happen. Investors who do not filter at all spend all their time being thorough on the wrong properties and never close on anything.