Where the two-unit stock actually is
Delaware County’s small multi-unit housing is concentrated in the older eastern boroughs and townships, and the census numbers say so. Upper Darby Township counted 33,506 housing units in the 2024 American Community Survey, of which 2,766, about 8%, sit in two-unit structures, with another 7% in three and four unit buildings. In the Yeadon postal area, 10.5% of units are in two-unit structures. In the Darby postal area it’s 13.4%.
That is unusual for a Philadelphia suburb, and it sits on top of very old housing. Upper Darby went from 8,956 people in 1920 to 47,145 in 1930 after the El reached 69th Street, and 35% of the township’s housing was built in 1939 or earlier, with a median year built of 1948.
FHA and conventional on two to four units
FHA insures one to four units on the same loan as a single house, at 3.5% down with a 580 score, as long as you occupy one unit. You move in within 60 days of closing and stay at least a year. The 2026 Delaware County limits:
| Units | FHA limit |
|---|---|
| 1 | $630,200 |
| 2 | $806,750 |
| 3 | $975,200 |
| 4 | $1,211,950 |
Three and four unit buildings have to clear the self-sufficiency test: 75% of the appraiser’s market rent for every unit, yours included, must cover the whole monthly payment. Two-unit buildings skip it, which is the main reason most FHA multi-unit deals in this county are duplexes.
The conforming limits run higher: $1,066,250 for two units, $1,288,800 for three and $1,601,750 for four. Owner-occupied purchases go to 95% loan-to-value, a level Fannie Mae has allowed since November 2023 and Freddie Mac since September 2025, and you put in 3% of your own funds once the loan-to-value passes 80%.
Rate-and-term refinances on two to four units go to 95%. There is no self-sufficiency test on the conventional side.
The appraisal on a converted twin
The FHA property rules apply to the whole building, common areas included. On anything built before 1978, and in this housing stock that is most of it, the appraiser notes all defective paint and requires repair: interior and exterior surfaces, common areas, stairs, deck, porch, railings, windows and doors, plus fences, detached garages and sheds. Electrical adequacy gets judged across the building, and a shared basement with visible frayed or exposed wire is a write-up.
Access matters on a conversion. Under HUD’s rules the way into each unit cannot pass through another unit, though for attached dwellings it may be by alley, easement, common area or passage through the dwelling. If the second-floor apartment is reached by walking through the first-floor kitchen, that is a conversation to have with the lender before the appraisal is ordered.
Owner-occupancy, and what happens without it
Homeownership First, the county’s up-to-$10,000 down payment program, covers owner-occupied single-family property only. A twin counts. A rowhouse counts. A duplex does not, and neither does a renter-occupied house. It also excludes any property paying property tax to Chester City, Haverford Township or Upper Darby Township, which happens to be where a lot of the two-unit stock sits.
Upper Darby’s own first-time buyer program, up to $20,000 forgiven over five years, is limited to single dwelling units as well, and tenant-occupied properties are ineligible.
So the assistance and the duplex generally do not go together in Delco. The 3.5% down payment is doing the work on its own.
If you are not living in it, the owner-occupied programs are off the table and the file changes shape. Debt-service-coverage lending sizes the loan off the rent divided by the full monthly payment, and generally wants that ratio between 1.0 and 1.25. Expect a 620 to 680 minimum score, 20% to 25% down, two to twelve months of reserves, and often a prepayment penalty. Title in an LLC is usually fine on that kind of loan.
The township paperwork on a two-unit
The resale inspection cuts differently on a duplex. Under Act 133 of 2016, a municipality that inspects at resale issues a full use and occupancy certificate, a temporary one that lets ordinary violations get fixed after settlement, or a temporary access certificate that blocks occupancy until a substantial violation is corrected. Several Delco municipalities price the inspection per dwelling unit, so a duplex costs more and takes longer.
Upper Darby also requires a sewer lateral certification from a township-licensed contractor, valid for 90 days, and treats a missing certification as a substantial violation. One lateral, two units, one bill. Some towns run a yearly rental license with its own inspection on the unit you lease out, so ask the code office what applies before settlement, not after.