Possible, but the steep ground will be hard. The ground is steep, with slopes averaging about 29%. That raises the cost of a driveway, septic, and foundation. Water is easy here, with about 53 inches of rain a year and wells near 30 feet. The growing season runs about 365 frost-free days, long enough for a spring and a fall garden.
What the land says
Rain
Rain can supply much of a household's water with a large tank. A garden mostly waters itself in normal years.
About 53 inches a year (University of Hawaii Rainfall Atlas)
Wells
Shallow wells, so drilling should be one of the cheaper costs.
The typical well here is about 30 feet deep; a well typically runs $7,000 to $16,000
Growing season
Long enough for a spring and a fall garden.
About 365 frost-free days, USDA zone 13a; last frost about January 1, first about December 31
Sun
Strong sun. A modest solar array covers a household.
About 6.0 hours of full sun a day, averaged over the year
Flood
Flood zones run along creeks and rivers here. Look up the parcel on FEMA's flood map.
FEMA maps flood zones in places
Wildfire
Low wildfire risk.
U.S. Forest Service wildfire hazard map: Very Low to Moderate here
Storms
Hurricanes and strong tornadoes are rare here.
NOAA: one hurricane-strength storm within 50 miles since 1975; no strong (EF2 or stronger) tornado within 25 miles since 1990
Earthquakes
Strong shaking is possible. Build to the seismic code and brace the water tank.
USGS seismic hazard map: high
Terrain
Steep. A flat house site and a driveway route will drive the cost.
Slopes average about 29%, about 260 feet above sea level
Soil
Expect a costlier septic system, because the ground is steep. The county's soil test decides.
Silty clay loam, well drained (USDA soil survey). A mound, sand filter, or treatment unit typically runs $10,000 to $20,000
Road
Paved roads are close by.
Nearest paved road usually within about 0.7 miles (OpenStreetMap)
Check a Hawaii parcel, or plan the one you own
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A step-by-step build plan, sizing your solar, water, garden, septic, heat, and buildings.
Is it legal here?
Zoning
We found no public zoning map for Kalawao County, so call the county planning office with the parcel number to ask whether the land is zoned.
Building code
Hawaii has a statewide building code, with a residential code based on the 2018 International Residential Code. Each county adopts it with its own changes and enforces it through the county building department, so plan on a county building permit for a house.
Rainwater
Collecting it is allowed.
Composting toilets
Allowed with a permit and an approved unit.
Water rights
A mix of two systems. Ask the state water office before you drill a well or dam a creek.
Drilled to about 30 feet, with pump and pressure tank
Septic
$10,000 to $20,000
Mound, sand filter, or treatment unit
Solar and batteries
$18,000 to $34,000
Sized for a modest household
Road or driveway
$6,000 to $17,000
From the nearest road to a house site
Clearing
$2,000 to $9,000
A house site, solar, and garden
Total
$44,000 to $96,000
Before the house
Before you make an offer on land here
Soil test
Get a soil test before you count on septic.
Steep ground can rule out a standard system.
Flood map
Look up the parcel on FEMA's flood map.
Flood zones run along creeks and rivers here. Building in one means flood insurance and extra permits.
Zoning
Call the county planning office with the parcel number.
There is no public zoning map, so we cannot tell whether the land is zoned.
Nearby counties
81 people live in Kalawao County, about 6.8 per square mile. It ranks tied for 4th of the 5 Hawaii counties we scored, and Hawaii ranks 36th of 50 states.