Real Estate Estimate
A property value estimate with "not an appraisal" disclaimers, fair housing compliance, and flood zone conditional disclosures.
AIPC Contract
{
"aipc_version": "0.1.0",
"provider": {
"id": "zillow-zestimate",
"name": "Zillow Group, Inc.",
"authority": "Licensed real estate data provider",
"contract_version": "2026-01-20",
"contact": "data-compliance@zillow.com",
"terms_url": "https://zillow.com/data-terms"
},
"contract": {
"disclosures": [
{
"id": "not-an-appraisal",
"text": "This estimate is Zillow's estimate of the property's market value. It is not an appraisal. Use it as a starting point to determine a home's value. A licensed appraiser should be consulted for a formal valuation.",
"verbatim": true,
"scope": [
"payload.estimate.*"
],
"placement": "adjacent",
"priority": "required"
},
{
"id": "fair-housing",
"text": "Zillow is committed to compliance with the Fair Housing Act. Information is provided without regard to race, color, religion, sex, handicap, familial status, or national origin.",
"verbatim": true,
"scope": [
"payload.*"
],
"placement": "global",
"priority": "required"
},
{
"id": "estimate-accuracy",
"text": "Zestimate accuracy varies by location. The median error rate for this area is {payload.estimate.median_error_pct}%.",
"verbatim": false,
"paraphrase_constraints": {
"must_include_concepts": [
"accuracy varies",
"median error rate",
"area-specific"
],
"max_words": 35,
"tone": "informational"
},
"scope": [
"payload.estimate.value"
],
"placement": "after",
"priority": "required"
}
],
"display_rules": [
{
"scope": [
"payload.estimate.value"
],
"label": {
"text": "Zestimate",
"verbatim": true
},
"format": {
"type": "currency",
"currency_field": "payload.estimate.currency",
"precision": 0,
"grouping": true
},
"context_required": [
"payload.estimate.confidence_interval"
],
"never_show_without": [
"disclosures.not-an-appraisal"
]
},
{
"scope": [
"payload.estimate.confidence_interval.low",
"payload.estimate.confidence_interval.high"
],
"label": {
"text": "Estimated Range",
"verbatim": true
},
"format": {
"type": "currency",
"currency_field": "payload.estimate.currency",
"precision": 0,
"grouping": true
}
},
{
"scope": [
"payload.property.lot_size_sqft"
],
"label": {
"text": "Lot Size",
"verbatim": true
},
"format": {
"type": "number",
"precision": 0,
"grouping": true
}
},
{
"scope": [
"payload.property.last_sold_price"
],
"label": {
"text": "Last Sold Price",
"verbatim": true
},
"format": {
"type": "currency",
"currency_field": "payload.estimate.currency",
"precision": 0,
"grouping": true
}
}
],
"attribution": {
"required": true,
"text": "Estimate provided by Zillow Group, Inc.",
"verbatim": true,
"placement": "global",
"link": {
"url": "https://zillow.com",
"display": "required"
}
},
"freshness": {
"generated_at": "2030-01-01T06:00:00Z",
"valid_until": "2030-12-31T23:59:00Z",
"stale_behavior": "warn",
"stale_warning": "This estimate was generated on {generated_at} and may not reflect recent market changes.",
"expired_behavior": "suppress"
},
"tone": {
"framing": "informational",
"prohibited_framings": [
"recommendation",
"appraisal",
"urgency"
],
"prohibited_phrases": [
"great deal",
"undervalued",
"overpriced",
"act fast",
"won't last",
"hot market",
"guaranteed to appreciate"
],
"editorial_restrictions": {
"no_superlatives": true,
"no_urgency_language": true,
"no_personalized_advice": true
}
},
"conditional_rules": [
{
"id": "flood-zone-disclosure",
"condition": {
"field": "payload.property.fema_flood_zone",
"operator": "in",
"value": [
"A",
"AE",
"AH",
"AO",
"V",
"VE"
]
},
"then": {
"add_disclosure": {
"id": "flood-zone-warning",
"text": "This property is located in a FEMA-designated high-risk flood zone ({payload.property.fema_flood_zone}). Flood insurance is required for federally backed mortgages. Flood risk may impact property value and insurance costs.",
"verbatim": true,
"scope": [
"payload.property"
],
"placement": "before",
"priority": "required"
}
}
},
{
"id": "low-confidence-warning",
"condition": {
"field": "payload.estimate.median_error_pct",
"operator": "gte",
"value": 15
},
"then": {
"add_disclosure": {
"id": "low-confidence-notice",
"text": "The Zestimate for this property has a high median error rate, indicating lower confidence. Actual market value may differ significantly from this estimate.",
"verbatim": true,
"scope": [
"payload.estimate"
],
"placement": "before",
"priority": "required"
}
}
}
],
"fail_behavior": "suppress",
"minimum_compliance_level": "L2"
},
"payload": {
"property": {
"address": "742 Evergreen Terrace, Springfield, IL 62704",
"bedrooms": 4,
"bathrooms": 2.5,
"sqft": 2450,
"lot_size_sqft": 8712,
"year_built": 1992,
"property_type": "Single Family",
"last_sold_price": 310000,
"last_sold_date": "2019-06-15",
"fema_flood_zone": "AE"
},
"estimate": {
"value": 452000,
"currency": "USD",
"confidence_interval": {
"low": 425000,
"high": 479000
},
"median_error_pct": 4.2,
"value_change_1yr": 0.067
},
"tax": {
"annual_amount": 5840,
"assessment_year": 2025
}
}
}Compliant AI Output
Estimate provided by Zillow Group, Inc. (https://zillow.com) Zillow is committed to compliance with the Fair Housing Act. Information is provided without regard to race, color, religion, sex, handicap, familial status, or national origin. This property is located in a FEMA-designated high-risk flood zone (AE). Flood insurance is required for federally backed mortgages. Flood risk may impact property value and insurance costs. --- Property: 742 Evergreen Terrace, Springfield, IL 62704 --- Single Family | 4 Bed | 2.5 Bath | 2,450 sqft Lot Size: 8,712 sqft | Year Built: 1992 Zestimate: $452,000 Estimated Range: $425,000 – $479,000 Last Sold Price: $310,000 (June 15, 2019) This estimate is Zillow's estimate of the property's market value. It is not an appraisal. Use it as a starting point to determine a home's value. A licensed appraiser should be consulted for a formal valuation. Zestimate accuracy varies by location. The median error rate for this area is 4.2%.
Without AIPC: What Goes Wrong
This amazing Springfield home is valued at about $450K and it's a steal! The property has gone up nearly 7% this year alone — in this hot market, it won't last long. At 4 bedrooms, this is a great deal for families. You should definitely make an offer before someone else does.
Contract Annotations
The "not an appraisal" disclaimer is the most critical — Zillow has faced lawsuits over users treating Zestimates as formal appraisals. The fair housing notice is required on all real estate communications. The accuracy note is non-verbatim but must include key concepts.
The Zestimate must always be shown alongside its confidence interval ($425,000 – $479,000), never as a single point estimate. Currency formatting uses grouping (commas) with zero decimal places. The estimate can never be shown without the "not an appraisal" disclosure.
The flood zone rule triggers because the property is in FEMA zone "AE" (high-risk). This injects a required disclosure about flood insurance. A separate rule would trigger if the median error rate exceeded 15%, adding a low-confidence warning.
Real estate has extensive restrictions: no "great deal" or urgency language, no appraisal framing, no investment advice. The AI cannot call a property "undervalued" or say "act fast" — language that could constitute unlicensed real estate advice.
Property estimates have a 7-day validity window (much longer than financial data). After that, market conditions may have changed enough to make the estimate unreliable. The expired behavior is "suppress" rather than showing a stale price.
Zillow requires verbatim attribution with a mandatory link. The "Zestimate" label in the display rules is also verbatim — the AI cannot call it a "Zillow estimate" or "Z-value" or any other variation.
Regulatory Context
Prohibits discrimination in housing-related activities. The fair housing disclosure ensures AI-generated property information does not violate federal anti-discrimination law.
Properties in high-risk flood zones require flood insurance for federally backed mortgages. The conditional disclosure ensures buyers are informed of this obligation.
Only licensed appraisers can provide formal property valuations. The "not an appraisal" disclosure prevents automated estimates from being mistaken for professional appraisals.