Off-grid site report
Douglas County, CO
39.4805, -104.7573 · 5,978 ft elevationRead this before you act on anything below. This is my researched starting point for Douglas County, CO, not legal advice and not a guarantee. Rules change, and the deciding facts on any specific parcel (setbacks, perc results, overlay districts, deed restrictions, road frontage) live at the county or town office, not in any database. Before you buy land or build, confirm the current rules directly with the local zoning and health offices - the sources on this page tell you exactly who to call.
The local rulesDouglas County, CO
Zoning & raw-land occupancy
Varies locallyThe Douglas County Zoning Resolution (DCZR), administered by County Planning Services, governs unincorporated land only; incorporated towns like Castle Rock and Parker have separate codes. Districts (RR, ER, SR, A-1) set lot size, density, and setback rules, generally allowing one principal home per parcel plus recently expanded ADU options. source
Dwellings, tiny homes & RVs
Varies locallyADUs are now permitted in several residential districts with minimum lot sizes tied to water source (1 acre on central water/septic, 2 acres on private well/septic). RVs or tiny homes on wheels as permanent residences are not confirmed as permitted; ask County Planning directly. source
Building permits & codes
RestrictedUnincorporated Douglas County requires building permits through the County Building Division, though exact code editions weren't confirmed in this research; the DCZR references permit-triggering activity and a waiver process for development standards. source
Septic & composting toilets
RestrictedThe Douglas County Health Department's Environmental Health division permits and inspects onsite wastewater treatment systems (OWTS) under county regulation layered on the state's OWTS Act; composting toilets are not explicitly addressed and should be confirmed directly with the department. source
Greywater reuse
Unclear - verifyNo official Douglas County page confirms an adopted local greywater reuse program; county workshop materials discuss it only as a future policy option, so the state's restrictive baseline applies until the county says otherwise. Confirm with County Planning or Environmental Health.
Rainwater harvesting
Unclear - verifyDouglas County has not been confirmed to adopt any expansion of the state's limited rainwater harvesting allowances; local incentives were only discussed as proposals in a county workshop, not enacted. Confirm with County Planning.
Private wells & water rights
RestrictedNew wells require permitting through the Colorado Division of Water Resources / State Engineer's Office under state law; county zoning separately ties minimum lot size for ADUs to whether a private well is used. source
Living disconnected from utilities
Varies locallyOff-grid power such as solar isn't restricted by the DCZR, but the zoning code requires dwellings to have an approved water source and OWTS compliance, so full disconnection from water/waste systems isn't allowed without meeting those permitting requirements. source
Sun30-year normals
- Peak-sun hours, annual average
- 5.9 hrs/day
- Worst month (sizes an off-grid array)
- 4.7 hrs/day
- Yearly output per 1 kW of panels
- 1,668 kWh
JFMAMJJASOND
Weather1991-2020
- Precipitation
- 19 in/yr
- Heating degree days
- 6,273 (cold)
- Frost-free season
- May 11 to Sep 29
How far help isstraight-line
- Hospital
University of Colorado Hospital - 18.7 mi
- Fire station
Rattlesnake Fire Protection District Station 54 - 6.1 mi
- Hardware store
Big Tool Box - 10.8 mi
- Grocery
Sprouts Farmers Market - 4.1 mi
From OpenStreetMap. Road miles will be longer, often much longer in hill country.
Plan this spot
These open with this location's real numbers already filled in (ZIP 80138).
Size a solar systemHeat loss & insulationFirewood per winterRainwater harvestGarden sizePanel tilt
Looking at a specific parcel in Douglas County, CO?The rules above are the jurisdiction. The land check runs the parcel itself: flood zone, soils and septic suitability, wetlands, slope, access, climate, and these verdicts, from a parcel number or coordinates.
Check a parcel →Share or save this report:New report
Sources: US Census Bureau geocoder; NLR PVWatts v8 (solar); NOAA NCEI 1991-2020 climate normals (nearest station) or Open-Meteo (ZIP-centroid) for weather; Open-Elevation; OpenStreetMap contributors. Public data retrieved Aug 21, 2026; agencies update their layers on their own schedules. Planning data, not a survey or legal advice.
New here, or not sure where this fits? Start here walks through the whole thing in order.