Decimal-Acre Reference / Sheet 0.03
0.03 Acres = 1,307 sq ft
Three hundredths of an acre, the size of a typical US two-bedroom apartment. Just above the California Senate Bill 9 minimum split-lot floor and big enough to host a small detached accessory dwelling unit. The math is exact: 0.03 multiplied by 43,560 equals 1,306.8 square feet.
Square Feet
1,306.8
international ft2
Square Metres
121.41
m2
Hectares
0.0121
ha
Derivation: 0.03 acres × 43,560 sq ft per acre = 1,306.8 sq ft, exactly. Per the 1959 IYPA international acre.
Sheet 02 · The ADU-Class Parcel
What 1,307 square feet of land enables
A 0.03-acre parcel sits in a useful gap. It is too small for a conventional single-family detached house in suburban zoning (minimum typically 5,000 sq ft) and big enough to host a substantial accessory structure on its own. The most common contemporary use is the detached accessory dwelling unit (ADU), a category of housing that California legalised statewide in 2017 and that has since spread to Oregon, Washington, Vermont, and most of the western US municipal codes. A statewide-permitted detached ADU in California can be up to 1,200 sq ft and as small as 150 sq ft, with permitting that the city must approve by-right within 60 days. On a 0.03-acre parcel produced by an SB-9 lot split, an 800 to 1,000 sq ft ADU is the typical build.
Outside the West Coast, the 0.03-acre size class shows up in older urban grids as substandard lots. A typical Detroit historic neighbourhood platted in the 1900s used 25-foot frontages on 50- to 60-foot depths (1,250 to 1,500 sq ft per lot). Many of these lots are vacant after the city's population decline, and parts of the Detroit Land Bank inventory consists of 0.03-acre parcels available at $100 to $1,000 each through the side-lot programme. These cannot generally be built on as standalone houses but can be combined with adjacent lots to form a buildable parcel.
On the commercial pad side, 0.03 acres holds a small drive-through coffee kiosk, a single-bay car-detail shed, an outdoor seasonal vendor stall (the typical farmers' market booth allocation is 100 to 200 sq ft, so 0.03 acres holds 6 to 13 booths), or a satellite cell-tower compound at the high end. The Maryland State Highway Administration uses parcel sizes between 800 and 1,500 sq ft for its electronic-toll gantry foundations and DOT field-equipment vaults along Interstate 95.
For an intuitive sense of how much room 1,307 sq ft is, think of a basketball court's painted lane (the key) at 380 sq ft. A 0.03-acre parcel is about 3.4 keys side by side. A standard squash court is 691 sq ft, so 0.03 acres is about 1.9 squash courts. A typical American suburban two-car garage is 484 sq ft, so 0.03 acres is about 2.7 two-car garages. These help give a physical sense of the area without needing to visit a real lot of that size.