Scaling a Washington Rental Portfolio: Past 4 Doors, Past 10, and Beyond
Program and regulatory figures verified July 24, 2026. Details change; confirm your scenario with us.
Every Washington portfolio hits the same three walls: the conventional property-count cap, the reserve requirements that climb with it, and tax returns that stop telling the story. Each has a clean answer.
How many financed properties can I have?
Ten, conventionally. Fannie Mae's B2-2-03 allows up to 10 financed properties per borrower when the new loan is on a second home or investment property. The "you can only have four mortgages" claim you'll still hear at meetups describes policy that ended in 2009. What does climb as you grow is the reserve requirement, measured against the aggregate unpaid balance of your other financed properties: 2% with 1–4 financed properties, 4% with 5–6, and 6% with 7–10. Eligibility standards also tighten as the count rises, so files at 7 or more want clean credit and organized documentation.
Past ten (or well before it, once returns and reserve math get heavy), DSCR takes over. No agency property-count cap exists on DSCR programs; each property qualifies on its own rent-to-payment ratio. Our usual sequencing for Washington investors: conventional while it's cheapest and your tax returns cooperate, DSCR from there. The comparison mechanics live in the DSCR guide, and the entity structure most portfolios adopt on the way is in the LLC guide.
The 2–4 unit lane and the conforming limits
Duplexes through fourplexes are still residential financing (one loan, one address, several rent checks), and every unit's rent counts toward a DSCR ratio, which is how a fourplex clears 1.0 where a same-price single-family can't. Plan on 25% down as the common floor on investment 2–4 unit, conventional or DSCR. The 2026 one-unit conforming limit is $832,750 across most of Washington, rising to $1,063,750 in King, Pierce, and Snohomish counties (the Seattle–Tacoma–Bellevue high-cost band), with higher 2–4 unit limits on the FHFA table. In the high-price metros those elevated limits are what keep a small-multifamily purchase inside conforming territory.
The HB 1337 ADU angle: turning one lot into three rents
Washington handed scaling investors a structural tool most states don't have. HB 1337 requires cities in urban growth areas to allow 2 ADUs per lot and bars them from imposing owner-occupancy requirements. So an investor can buy a single-family house, add a backyard cottage and a basement or garage unit, and rent all three, converting a single-family purchase into small-multifamily economics on a single-family entry price. Two cautions we build into the plan. First, adding ADUs to a tenant-occupied rental does not create a rent-cap exemption; the owner-occupied exemption in RCW 59.18.710 needs the owner living on site, so a pure investor's three units are all capped (the rent-cap guide). Second, a newly-built ADU may carry its own 12-year new-construction exemption from the cap, which is an attorney question worth asking. The financing follows the finished rent roll on a DSCR file.
Foreign-national buyers of Washington rentals
Washington rentals draw international capital, especially into the Puget Sound metros, and financing exists for it: DSCR-style foreign-national programs require no U.S. credit score or Social Security number on many structures. Expect 25–30% down, reserves on the deeper end (6–12 months), and foreign bank assets documented rather than moved. An ITIN is sometimes needed for tax administration, not for qualifying; your CPA handles that side. The property still qualifies on its rent-to-payment ratio like any other DSCR file, and title can vest in a U.S. entity: the usual structure pairs a Washington LLC with a foreign member, papered by a Washington attorney at closing.
No pressure, no obligation, and no salesy follow-up: a 20-minute call with our team, real numbers, and a straight answer on whether the deal pencils.
Frequently asked questions
How many financed properties can I have with conventional loans?
Up to 10 per borrower under Fannie Mae B2-2-03 for second-home and investment purchases. Reserve requirements climb with the count: 2% of the aggregate balance of your other financed properties at 1–4, 4% at 5–6, and 6% at 7–10. The four-property limit people still cite ended in 2009.
What happens when I hit the 10-property cap?
DSCR financing takes over: no agency property-count cap exists, and each property qualifies on its own rent against its own payment. Many investors switch earlier than 10, when conventional reserve math and tax-return documentation get heavier than DSCR's simpler file. The crossover point is a numbers question we can run for your portfolio.
Can a foreign national buy Washington investment property with financing?
Yes. Foreign-national DSCR programs on many structures require no U.S. credit score or Social Security number; plan on 25–30% down and 6–12 months of reserves, with foreign assets documented. An ITIN may be needed for taxes rather than qualification. Title typically vests in a Washington LLC at closing.
Can I add ADUs to a Washington rental and finance the extra units?
Yes: HB 1337 makes cities in urban growth areas allow 2 ADUs per lot with no owner-occupancy requirement, so you can convert a single-family buy into three rents. A DSCR loan follows the finished rent roll. Note that a pure investor's ADU units are still under the rent cap, since the owner-occupied exemption needs the owner on site.
Mike Certo · NMLS #260555 · Cornerstone First Mortgage NMLS #173855 · Equal Housing Lender. Educational content, not a loan commitment and not legal or tax advice. Washington's rent-cap figures, city and county STR rules, and tax figures change; verify current requirements with the city or county, your CPA, or a Washington real estate attorney before you buy. Loans are subject to buyer and property qualification.