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Garden CityResearchMethodology
MethodologyJuly 19, 2026· Renew

Garden City Research Methodology and Data Sources

Page type: Methodology

Breadcrumb: Garden City / Research / Methodology

Page type: Methodology
Published: 2026-05-05
Read time: 8 minutes

Garden City investment research at Renew Group is built on a tiered source hierarchy that prioritizes official government data, verified public market sources, and operator-validated field intelligence—with every metric tagged by confidence level, geographic scope, and update cadence to ensure institutional-grade diligence standards.

Source Hierarchy

All Garden City data follows a five-tier verification standard, with higher tiers overriding lower tiers when conflicts arise:

Tier 1: Official Government Sources (VERIFIED)

City of Garden City official publications

Ada County Assessor

  • Parcel data, assessed values, ownership records: https://adacounty.id.gov/assessor/
  • Update cadence: Annual assessment cycle (January 1 valuation date); sales data updated weekly

U.S. Census Bureau

  • Population estimates (ACS 5-Year 2019-2023): https://data.census.gov
  • Decennial Census 2020: https://data.census.gov/cedsci/
  • Update cadence: ACS 5-Year data released annually in December; PEP county estimates released annually in March
  • Geographic scope: Garden City city limits (Place FIPS 16-29620)
  • Confidence note: ACS 1-Year estimates not published for places under 65,000 population; 5-Year estimates used for Garden City

Idaho State Legislature

Tier 2: Verified Public Market Data (VERIFIED / ESTIMATED)

Redfin Data Center

  • Median sale price, days on market, inventory levels: https://www.redfin.com/city/7547/ID/Garden-City/housing-market
  • Geographic scope: Garden City city limits
  • Update cadence: Monthly (data typically 30–45 days lagged)
  • Confidence level: VERIFIED for closed sales; ESTIMATED for pending/active inventory
  • Methodology: MLS-sourced transaction data; Redfin proprietary estimates for market trends

Realtor.com Market Trends

Zillow Home Value Index

  • Median home values, historical trends: https://www.zillow.com/home-values/11572/garden-city-id/
  • Geographic scope: Garden City city limits
  • Update cadence: Monthly
  • Confidence level: ESTIMATED (Zillow proprietary model, not MLS transaction data)
  • Methodology: Zestimate algorithm incorporating public records, MLS data, and user-submitted information

COMPASS (Community Planning Association of Southwest Idaho)

  • Regional growth forecasts, transportation planning, land use trends: https://compassidaho.org
  • Geographic scope: Ada County and Treasure Valley region
  • Update cadence: Annual reports; ad-hoc policy briefs
  • Confidence level: VERIFIED for historical data; ESTIMATED for projections

Tier 3: Broker and Industry Sources (ESTIMATED / OPERATOR)

Cushman & Wakefield Boise Market Reports

CoStar / LoopNet

  • Commercial property listings, lease comps, cap rate surveys
  • Geographic scope: Garden City and Boise metro
  • Update cadence: Real-time listings; quarterly market reports
  • Confidence level: ESTIMATED (self-reported by brokers and owners)

Local broker surveys and market commentary

  • Anecdotal pricing trends, buyer sentiment, deal flow
  • Confidence level: OPERATOR (field intelligence, not verified by third-party data)

Tier 4: Renew Internal Analysis (OPERATOR)

Renew Group proprietary underwriting

  • Deal-level analysis, ARV estimates, rent projections, cap rate assumptions
  • Methodology: Comparative market analysis using Tier 1–3 sources; adjusted for property-specific conditions
  • Confidence level: OPERATOR
  • Labeling: All Renew interpretations tagged "Renew take:" in briefs and marked [RENEW_TAKE] in source annotations

Field intelligence

  • On-the-ground observations, contractor bids, permitting timelines, neighborhood sentiment
  • Confidence level: OPERATOR
  • Use case: Directional guidance for active deals; not cited as fact in public research

Tier 5: Speculative or Unverified Claims (FLAGGED)

Any claim without a Tier 1–4 source is flagged `` and not published until verified.

Confidence Levels

Every metric in Garden City research is tagged with one of four confidence levels:

VERIFIED

  • Source: Official government publication, MLS closed transaction data, or audited financial report
  • Example: "Garden City median sale price $609,000 (Redfin, March 2026)" — VERIFIED
  • Use case: Underwriting assumptions, investor presentations, public briefs

ESTIMATED

  • Source: Broker survey, proprietary model (Zillow, Redfin), or industry report with disclosed methodology
  • Example: "Garden City median rent $2,170/mo (Realtor.com, January 2026)" — ESTIMATED (based on listing ask, not closed leases)
  • Use case: Directional guidance; confirm with Tier 1 source before final underwriting

OPERATOR

  • Source: Renew internal analysis, field intelligence, or broker anecdote
  • Example: "Renew take: Garden City flips are underpriced relative to Boise West End comps by 15–20% on a $/sqft basis" — OPERATOR
  • Use case: Deal screening, market positioning; not cited as fact in public research

DATED

  • Source: Any Tier 1–3 source older than 12 months (or 6 months for fast-moving metrics like inventory or DOM)
  • Example: "Garden City population 12,316 (U.S. Census 2020)" — DATED (2020 Decennial Census; 2023 ACS 5-Year estimate available)
  • Use case: Historical context only; flag for update before publication

Update Cadence by Data Type

Monthly updates:

  • Median sale price, days on market, active listings (Redfin, Realtor.com)
  • New listings, pending sales (Realtor.com)
  • Median rent (Realtor.com, Zillow)

Quarterly updates:

  • Multifamily cap rates, absorption, rent growth (Cushman & Wakefield)
  • Commercial property trends (CoStar)

Annual updates:

  • Population estimates (U.S. Census ACS 5-Year, released December)
  • County population estimates (U.S. Census PEP, released March)
  • Assessed values (Ada County Assessor, January 1 valuation date)
  • COMPASS regional forecasts

Ordinance-triggered updates:

  • Zoning code amendments (tracked via Garden City P&Z agendas, third Wednesday monthly)
  • Comprehensive Plan amendments (tracked via City Council agendas)
  • State legislation (tracked during Idaho legislative session, January–March)

Ad-hoc updates:

  • Major development approvals (tracked via P&Z staff reports)
  • Significant market events (e.g., large portfolio sales, major employer announcements)

Geographic Scope Definitions

City limits (Garden City proper)

  • Definition: Incorporated area within Garden City municipal boundaries
  • FIPS code: 16-29620
  • Use case: Population, zoning, ordinance research
  • Sources: City of Garden City, U.S. Census Bureau

Ada County

  • Definition: County containing Garden City, Boise, Meridian, Eagle, Kuna, Star
  • Use case: Assessor data, regional market trends
  • Sources: Ada County Assessor, COMPASS

Boise metro / Treasure Valley

  • Definition: Ada County + Canyon County (includes Nampa, Caldwell, Middleton)
  • Use case: Regional economic trends, multifamily cap rates, employment data
  • Sources: COMPASS, Cushman & Wakefield, U.S. Census Bureau MSA data

Neighborhood-level

  • Definition: Informal submarket within Garden City (e.g., Live-Work-Create District, Greenbelt Corridor)
  • Use case: Hyperlocal pricing trends, asset-class relevance
  • Sources: Renew internal analysis, MLS micro-market data, field intelligence
  • Confidence level: OPERATOR (no official neighborhood boundaries in Garden City)

Parcel-level

  • Definition: Individual tax lot
  • Use case: Zoning verification, ownership research, assessed value
  • Sources: Ada County Assessor, Garden City GIS

Primary Sources (Canonical List)

Government:

  1. City of Garden City Code (Title 8 Development Code): https://library.municode.com/id/garden_city/codes/code_of_ordinances?nodeId=TIT8DECO
  2. Garden City Development Services: https://gardencityidaho.org/departments/development-services/
  3. Garden City Planning & Zoning Commission: https://gardencityidaho.org/planning-and-zoning-commission/
  4. Ada County Assessor: https://adacounty.id.gov/assessor/
  5. U.S. Census Bureau: https://data.census.gov
  6. Idaho State Legislature: https://legislature.idaho.gov
  7. COMPASS: https://compassidaho.org

Market data: 8. Redfin Data Center: https://www.redfin.com/city/7547/ID/Garden-City/housing-market 9. Realtor.com Market Trends: https://www.realtor.com/local/market/idaho/ada-county/garden-city 10. Zillow Home Value Index: https://www.zillow.com/home-values/11572/garden-city-id/ 11. Cushman & Wakefield: https://www.cushmanwakefield.com/en/united-states/insights 12. CoStar / LoopNet: https://www.costar.com

Renew internal: 13. Renew Group proprietary underwriting (OPERATOR) 14. Field intelligence (OPERATOR)

Methodology for Specific Metrics

Population estimates

  • Source: U.S. Census Bureau ACS 5-Year (2019-2023) for Garden City; PEP Vintage 2023 for Ada County
  • Confidence level: VERIFIED
  • Update cadence: Annual (ACS released December; PEP released March)
  • Geographic scope: City limits (Place FIPS 16-29620) for Garden City; county-level for Ada County
  • Methodology: ACS 5-Year rolling average (2019-2023 data released December 2024); PEP annual estimate (July 1, 2023 estimate released March 2024)
  • Limitation: ACS 1-Year not published for places under 65,000 population; 5-Year estimate lags current year by 1–2 years

Median sale price

  • Source: Redfin Data Center
  • Confidence level: VERIFIED (closed sales); ESTIMATED (pending/active)
  • Update cadence: Monthly (30–45 day lag)
  • Geographic scope: Garden City city limits
  • Methodology: MLS-sourced closed transaction data; median calculated from all arms-length sales in reporting period
  • Limitation: Small sample size in low-volume months (fewer than 10 sales) may produce volatile month-to-month swings

Days on market (median)

  • Source: Redfin Data Center
  • Confidence level: VERIFIED
  • Update cadence: Monthly
  • Geographic scope: Garden City city limits
  • Methodology: Median days from MLS listing date to accepted offer date for closed sales in reporting period

Active listings

  • Source: Realtor.com Market Trends
  • Confidence level: VERIFIED
  • Update cadence: Monthly
  • Geographic scope: Garden City city limits
  • Methodology: Count of active MLS listings as of month-end snapshot

Median rent

  • Source: Realtor.com Market Trends
  • Confidence level: ESTIMATED
  • Update cadence: Monthly
  • Geographic scope: Garden City city limits
  • Methodology: Median asking rent from active rental listings (not closed leases)
  • Limitation: Asking rent may differ from closed lease rent by 5–10%; use for directional guidance only

Multifamily cap rates

  • Source: Cushman & Wakefield Boise Market Reports
  • Confidence level: ESTIMATED
  • Update cadence: Quarterly
  • Geographic scope: Boise metro (includes Garden City as submarket)
  • Methodology: Broker survey of recent sales and market sentiment; cap rates calculated from reported NOI and sale price
  • Limitation: Small sample size; cap rates vary widely by asset quality, location, and financing terms

Zoning and ordinance data

  • Source: City of Garden City Code Title 8 (Development Code)
  • Confidence level: VERIFIED
  • Update cadence: Ordinance amendments tracked monthly via P&Z agendas
  • Geographic scope: Garden City city limits
  • Methodology: Direct citation of municipal code sections; amendments tracked via staff reports and adopted ordinances
  • Verification requirement: All zoning claims include ordinance number, effective date, and official source URL; users instructed to verify at official source before any development decision

Data Quality Standards

Publication safety:

  • All numeric claims require inline citation with source name and date
  • All metrics tagged with confidence level (VERIFIED / ESTIMATED / OPERATOR / DATED)
  • All ordinance references include specific code section, effective date, and official URL
  • All Renew interpretations labeled "Renew take:" and tagged [RENEW_TAKE]
  • Unsourced claims flagged `` and not published until verified

Source citation format:

  • Inline: "Garden City median sale price $609,000 (Redfin, March 2026)"
  • Stat card: [STAT_CARD: value="$609,000" | label="Median sale price" | source="Redfin" | date="2026-03-01" | confidence="VERIFIED"]
  • Sources block: Full source list with name, URL, date accessed

Update discipline:

  • All data-bearing pages display "Last updated" date
  • Metrics older than 12 months (or 6 months for fast-moving data) flagged DATED
  • Ordinance amendments tracked within 30 days of adoption
  • Market briefs published quarterly or upon significant market events

Sources

  1. City of Garden City Code Title 8 (Development Code) — https://library.municode.com/id/garden_city/codes/code_of_ordinances?nodeId=TIT8DECO — Accessed 2026-05-05
  2. Garden City Development Services — https://gardencityidaho.org/departments/development-services/ — Accessed 2026-05-05
  3. Garden City Planning & Zoning Commission — https://gardencityidaho.org/planning-and-zoning-commission/ — Accessed 2026-05-05
  4. Ada County Assessor — https://adacounty.id.gov/assessor/ — Accessed 2026-05-05
  5. U.S. Census Bureau — https://data.census.gov — Accessed 2026-05-05
  6. Idaho State Legislature — https://legislature.idaho.gov — Accessed 2026-05-05
  7. COMPASS — https://compassidaho.org — Accessed 2026-05-05
  8. Redfin Data Center — https://www.redfin.com/city/7547/ID/Garden-City/housing-market — Accessed 2026-05-05
  9. Realtor.com Market Trends — https://www.realtor.com/local/market/idaho/ada-county/garden-city — Accessed 2026-05-05
  10. Zillow Home Value Index — https://www.zillow.com/home-values/11572/garden-city-id/ — Accessed 2026-05-05
  11. Cushman & Wakefield — https://www.cushmanwakefield.com/en/united-states/insights — Accessed 2026-05-05
  12. CoStar / LoopNet — https://www.costar.com — Accessed 2026-05-05

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[UPDATE_LOG_ENTRY] · change_type: created · change_summary: "Initial publication of Garden City research methodology and data sources." · editor_name: "Renew" · change_date: 2026-05-05

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