GroundRules
GroundRules · property intelligence

Know what's buildable — and how to get there.

ADU and property-use lead screening for builders, permit expediters, realtors, and property professionals. GroundRules helps flag zoning, land-use, hazard, and review-risk signals — and shows what still needs human or city review.

See if your address is supportedEvery fact tied to an official sourceFree if your jurisdiction isn't covered
4178 Whitfield Ave, Sacramento County, CA
ADU · detached
Screening status
Requires verification

Detached ADU up to 800 sq ft may be worth deeper review. 2 conditions require verification.

Confidence score82%
5
PASS
2
COND.
1
UNKN.
Rule trace · §309-55
  • Eligible zone (RD-3)§309-55(a)
  • Lot minimum met§309-55(b)
  • Rear setback ≥ 4 ft§309-55(c)
  • No additional parking req.CA Gov §65852.2
  • Ministerial approval eligibleCA Gov §65852.21
  • VHFHSZ fire hazard overlayCAL FIRE
  • Sewer connection capacitySacSewer
  • Historic district notice§309-55(h)
Unknowns — shown, not hidden
  • Ask city:Is sewer capacity available at this parcel's service connection point?
  • Ask city:Does this parcel require historic district notice before ministerial approval?
Sources cited
CA Gov Code §65852.22026-01-15
Sac County ADU Ord. §309-552026-03-01
CAL FIRE FHSZ State overlay2025-09-01
Permit path
Pre-app meeting
Plans submitted
Building review
Fire review
Permit issued
Inspections
Address intakeParcel dataRule engineScreeningPermit pathHuman review
4 min
Typical written screening packet
100%
Facts tied to a cited source
1 of 50
States we expand into, one county at a time
$0
If your jurisdiction isn’t covered yet
How it works

From address to a screening packet you can act on.

Address → project → zoning and land-use signals → risks → sources → report. The path is deterministic, cited, and human-reviewed.

01

Enter your address & project

Tell us the property and what you want to build — an ADU, a garage conversion, and more over time.

02

We pull verified parcel & zoning data

Lot size, zoning district, overlays, and hazard layers — from official records, with retrieval dates.

03

Deterministic rules produce screening signals

Each rule returns PASS, CONDITIONAL, or UNKNOWN against the cited code. GroundRules shows screening signals and review flags — not final legal approval.

04

AI explains it in plain English

A human reviews every report, then you get a clear, cited packet: what looks worth deeper review, what is conditional, and what still needs city confirmation.

AI explains. Verified rules decide. Unknowns are shown, not hidden. Every conclusion ties to an official, dated source. This is decision support — not legal, engineering, or planning advice — and the user must verify with the city or county before acting.
What you can check

Start with ADUs. Grow by project type and jurisdiction.

ADU and garage conversion are live in the first supported jurisdiction. Every new project type and county is added one verified rule library at a time.

ADU & JADU

Detached, attached, and junior ADUs.

Garage conversion

Convert existing structures to living space.

Room & bathroom additions

Coming soon

Footprint, coverage, and setback checks.

Solar & EV charging

Coming soon

Electrical and structural permit paths.

Pools & decks

Coming soon

Setback, fencing, and safety requirements.

Fences & sheds

Coming soon

Height limits and placement rules.

The core principle

AI explains. Verified rules decide. Unknowns are shown, not hidden.

The screening assessment never comes from a language model guessing. It comes from deterministic rules evaluated against official, dated sources. AI’s only job is to translate that into plain English — and a human reviews every report before it ships.

  • Verified rules decide. Each rule returns PASS / CONDITIONAL / UNKNOWN against a cited code section.
  • AI only explains. It paraphrases verified results. It cannot invent a rule or upgrade an unknown.
  • Unknowns are surfaced. Missing data becomes a specific question to ask the city — never a silent guess.
Rule-level transparency
  • PASSParcel is in unincorporated Sacramento County
  • PASSADU allowed in residential zone
  • PASSRear setback meets 4 ft minimum
  • PASSADU size within permitted limits
The translation

Your city’s rules exist. They’re written for lawyers.

We read the ordinance so you don’t have to, map it to your parcel, and cite the section every conclusion comes from.

§309-55(b) · municipal code

An accessory dwelling unit shall be permitted subject to subsection (b)(2) where the lot area exceeds the minimum prescribed in Table 4-1, provided that aggregate building coverage, inclusive of accessory structures as defined in §25-1-21(6), does not exceed the maximum impervious…

your report · plain english

Appears worth deeper ADU review up to 800 sq ft.

Keep 4 ft from the side lines, 6 ft from the rear.

You’re using 31% of your allowed 50% lot coverage. You have room.

2 conditions to verify (fire zone, sewer) and 1 unknown — all shown in your report.

Built jurisdiction-by-jurisdiction

City of Los Angeles is the first live beta jurisdiction.

We don’t scrape the country and hope it’s right. Each jurisdiction is onboarded with a verified, human-reviewed rule library. Other jurisdictions are being added one at a time after source verification.

City of Los Angeles, CA
First supported real-data lookup
Live beta
Orange County, CA
In assessment · next adapter candidate
Verified next
LA County (unincorporated), CA
Separate from City of LA · future expansion
Roadmap
Sacramento County, CA
Sample report only · not live real-data lookup
Sample only
San Diego County, CA
Priority expansion · in assessment
Roadmap
King County, WA
Nationwide roadmap
Roadmap

Coverage is expanding and is not yet complete. If your jurisdiction isn't supported, your report is free.

Note: City of Los Angeles and LA County (unincorporated) are distinct jurisdictions with separate planning authorities and ordinances. Only City of Los Angeles is currently supported for real-data lookup.

Local restriction signals

Flags for the restrictions that can kill a deal late.

GroundRules can surface source-backed local restriction signals where available and label the rest as human-review required. These are screening flags — not final legal opinions.

Short-term rental / Airbnb restriction review
Coastal zone / Coastal Commission review flag
Local ADU rule limitations
Long-term rental-only warnings where applicable
Case-by-case city review required
Missing facts that still need human or city confirmation
Roadmap · Local Restriction Watch

Track city-specific restrictions that may affect ADUs, short-term rentals, coastal properties, parking, fire hazard rules, and local permit review. These signals are source-backed where available and marked as human-review required when rules are incomplete or case-specific.

For homeowners

Don’t spend $100,000 on a guess.

Most homeowners commit before confirming their lot qualifies. A feasibility check costs less than the tile you’ll pick for the bathroom — and tells you the truth, with sources.

The decision you’re about to make$100,000+
What a wrong “probably fine” costs$11,000
Confirming before you start$149
Request a human-reviewed property packet
For builders · permit expediters · realtors · investors

Screen ADU and property-use leads before deeper diligence.

Useful for ADU builders, permit expediters, realtors, and investors screening fixer-uppers or listings with possible ADU/development potential.

  • Branded, client-ready PDFs
  • Lead qualification workflow
  • Local restriction risk flags
  • Missing facts called out for human/city review

Screen multiple ADU opportunities before deeper review.

The buildability layer

The same data, as an API for lenders, insurers & proptech.

Every report deposits structured, cited facts into a versioned buildability graph. As coverage grows, that graph becomes infrastructure — a buildability and development-rights API that platforms build on instead of rebuilding.

# GET /v1/feasibility
{
  "address": "4178 Whitfield Ave",
  "jurisdiction": "ca-sacramento-county",
  "project": "adu",
  "verdict": "FEASIBLE_WITH_CONDITIONS",
  "confidence": 0.82,
  "ruleset_version": "2026.06.0",
  "rules": [
    { "id": "adu.lot.eligible_zone",
      "status": "PASS",
      "source": "§309-55",
      "as_of": "2026-06-13" }
  ],
  "unknowns": 1
}
ADU · Garage conversion · More coming

Start with an honest LA-first ADU and property-use screen.

Get a written, source-cited screen before the plans, the architect, the offer, or the deposit.

Written verdict · Every fact cited · Free if your jurisdiction isn't covered