Possible, but water will be hard. Only about 14 inches of rain falls a year, so you will rely on a well or hauled water. The U.S. Forest Service rates wildfire risk high in parts of the county, so plan cleared ground around the house.
What the land says
Rain
Desert rain. Plan on a well or hauled water, and on irrigating anything you grow.
About 14 inches a year (PRISM, 1991 to 2020 average)
Wells
Well depth varies a lot here. Get a local driller's quote before you offer.
Typical well depths here range from 90 feet to 600 feet
Growing season
Enough for most vegetables. Start tomatoes and peppers indoors.
About 150 frost-free days, USDA zone 7a; last frost about May 9, first about October 5
Sun
Good sun. Size the array and battery bank for winter.
About 5.3 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 within a quarter mile in places
Wildfire
Wildfire risk is high in parts of the county. Check the risk for the parcel you want.
U.S. Forest Service wildfire hazard map: Very Low to High here
Storms
Hurricanes and strong tornadoes are rare here.
NOAA: no hurricane-strength storm within 50 miles since 1975; no strong (EF2 or stronger) tornado within 25 miles since 1990
Terrain
Rolling ground. Look for a flat house site.
Slopes average about 13%, about 3,110 feet above sea level
Soil
Good ground for a standard septic system. The county's soil test decides.
Loam, well drained (USDA soil survey). A standard system typically runs $5,000 to $10,000
Road
Paved roads are close by.
Nearest paved road usually within about 0.9 miles (OpenStreetMap)
Check an Idaho parcel, or plan the one you own
Get a free 0-100 off-grid score.
A step-by-step build plan, sizing your solar, water, garden, septic, heat, and buildings.
Is it legal here?
Zoning
Ada County zones land outside its towns and publishes its zoning map. Our free lookup shows the district for any address.
Building code
Idaho's residential code (the 2018 International Residential Code with state changes) is enforced only by cities and counties that choose to run a building permit program; where a county has none, there is no county building permit for a house.
Rainwater
Collecting it is allowed.
Composting toilets
Allowed.
Water rights
Water belongs to whoever claimed it first. A new well or pond may need a state permit, and a creek may already be claimed.
Depends on depth, which varies here. Get a driller's quote.
Septic
$5,000 to $10,000
Standard system
Solar and batteries
$18,000 to $34,000
Sized for a modest household
Road or driveway
$3,000 to $9,000
From the nearest road to a house site
Clearing
$1,000 to $5,000
A house site, solar, and garden
Total
$28,000 to $57,000
Before the house, plus the well
Before you make an offer on land here
Well depth
Get a local driller's depth estimate.
Typical well depths here range from 90 feet to 600 feet.
Wildfire
Ask an insurance agent whether they will write a policy.
The U.S. Forest Service rates wildfire risk high in parts of the county.
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.
Nearby counties
524,673 people live in Ada County, about 498.7 per square mile. It ranks tied for 14th of the 44 Idaho counties we scored, and Idaho ranks 40th of 50 states.