Buildability™Buildability ScoreWhat limits this score
Severe slope (~42%) · caps this score at 45
Ground this steep routinely forces engineered foundations, retaining structures, and a geotechnical report — and some jurisdictions cap development on slopes near this grade. Budget for site engineering before anything else. (USGS 3DEP (lot-scale slope))
No community water system serves this address
EPA maps no community water system reaching this point, so water is likely a private well. Budget for drilling, a yield test and water-quality testing, and check the county on well permits and minimum separation from any septic field. This is ordinary for rural land — it is a cost line, not an obstacle. (EPA (community water system boundaries))
Septic limitation not applied — servicing unknown
USDA rates this soil "Very limited" for septic absorption fields, but OpenStreetMap did not answer, so nothing here establishes whether the lot sits on an established street grid with sewer service. The septic constraint is not applied to the Score. If there is no sewer, it applies in full: a standard septic system likely fails here and an engineered system can cost tens of thousands more. Confirm service with the utility, or re-run when the street read is available. (USDA SSURGO (engstafdcd); OpenStreetMap street density did not answer)
Zoning coverage: A read of this jurisdiction’s own zoning code has been requested — the standards for RRD-B6-25 open in the full report once they’re verified against the ordinance text.
What we checked
Each factor is scored 0–100. Higher means fewer constraints.
| Factor | Score | Reading | Source |
|---|---|---|---|
| Zoning | — | not on record | no data |
| Flood | 95 | Minimal risk | FEMA NFHL |
| Seismic | 40 | Moderate risk | USGS Seismic |
| Soil | 72 | Suitable | USDA SSURGO |
| Radon | 90 | Minimal risk | EPA Radon |
| Wildfire | 50 | Moderate risk | USFS WHP |
| Utilities | — | not on record | no data |
| Terrain | 19 | Very steep | USGS 3DEP |
| Lot shape | 92 | Regular lot | Buildability engine |
On record: a building on this lot
Tailor this to your project — what are you building at 2199 DIAMOND MOUNTAIN RD?
Not checked here
The records behind this Score don’t answer these. Who does:
- Perc test
- The county health department
- Water or well capacity
- The water utility, for a will-serve letter; a well driller, for a yield test
- Recorded legal access and easements
- County recorder, or a title commitment
- CC&Rs and HOA rules
- The preliminary title report — before earnest money goes hard
- Title, liens and back taxes
- County treasurer, and the title search
Computed from public federal sources by the Buildability Score engine — the same records give the same number every time. Records read November 4, 2026. How the score works · Data sources · Accuracy
Informational only — not a permit, appraisal, or professional engineering opinion. Verify with your local planning department before acting on it. See Terms and data sources.
Questions about this score
What is the Buildability Score™ for 2199 DIAMOND MOUNTAIN RD, CALISTOGA, CA, 94515?
2199 DIAMOND MOUNTAIN RD, CALISTOGA, CA, 94515 carries a Buildability Score of 45 out of 100. The score is composed from 5 weighted factors, each cited to its federal or jurisdictional source, from records read November 4, 2026.
Which factor most affects 2199 DIAMOND MOUNTAIN RD, CALISTOGA, CA, 94515?
The weakest factor at this address is terrain — scored 19 out of 100, which reads as very steep (every factor is scored so that higher means fewer constraints). That's the factor most likely to constrain what a design can carry, and the one to inspect first before committing capital.
What's this parcel's strongest attribute?
Flood scores 95 out of 100 — minimal risk, and the highest of the 7 factors read for this address. Higher scores mean fewer constraints, not more.
Where does the data come from?
Every factor cites the federal or jurisdictional dataset it came from — FEMA (flood), USGS (seismic), USFS (wildfire), EPA (radon), USDA/NRCS (soil), and the local jurisdiction's own zoning record where available. These records were read November 4, 2026; a stored read older than 90 days is run again when this page is opened.
Does the Buildability Score account for local zoning in Napa County, CA?
When Napa County, CA's zoning record is on our roster, the score reads the jurisdiction's own dimensional standards for the district this parcel sits in. When it isn't, the zoning factor drops out rather than being estimated — which is why parcels in un-rostered jurisdictions still return a score, just one that doesn't count zoning.
Is this an official determination?
No. The Buildability Score™ is a preliminary due-diligence read, not an entitlement or permit approval. Governing bodies retain sole authority over binding land-use decisions. The score's role is to make the diligence conversation faster and better-grounded, not to replace it.