Methodology
How RentSift builds reports
RentSift aggregates publicly available data from federal, state, and local government agencies to produce address-level rental due diligence reports. Here is how each signal category works.
Crime incident data is sourced from local law enforcement agencies and government open data portals. Reports show the source window on the police row: most feeds use the last 12 months, while Fairfax County uses the current Fairfax Police weekly CSV when it has newer nearby records than the FCPOD layers. When the feed exposes block text, reports use matching public block labels first; otherwise they summarize the report mix inside published-coordinate distance bands. Nearby-area context stays separate from claims about the building itself.
Sources: Local law enforcement agencies, government open data portals
Code enforcement and 311 data from government portals. Where we have coordinates, we split requests within ~150 ft of the geocoded pin (a same-building / adjacent proxy) from the rest of the nearby radius. Fairfax PLUS matches the searched street address. Pest, noise, trash, and housing-maintenance categories are labeled where available.
Sources: County and city government 311 systems, code enforcement databases
When configured, Walk Score® (Walk Score API) supplies walk, transit, and bike scores. If the API is unavailable, we may fall back to OpenStreetMap-based transit density and similar signals only.
Sources: Walk Score (Smarter Travel Media LLC), OpenStreetMap / Open Database License (ODbL)
Residential electricity and natural gas rates from the OpenEI Utility Rate Database (NREL), combined with U.S. Census Bureau American Community Survey (ACS) housing and utility-cost patterns where applicable.
Sources: National Renewable Energy Laboratory (OpenEI), U.S. Energy Information Administration (EIA), U.S. Census Bureau
Building details, listed owner names, sale history, and property tax values come from official county or city property records where available. RentSift keeps these tied to the searched address and separates them from management-company or lease records.
Sources: DC CAMA / Owner Polygons, Maryland SDAT / MD iMAP, Fairfax County Tax Administration, Arlington County DataHub, Loudoun County GeoHub
Nearby grocery stores, convenience stores, pharmacies, parks, and gyms sourced from OpenStreetMap data via the Geoapify Places API. Reports emphasize distance, store type, and whether the nearby options are full grocery stores or lighter convenience-store context.
Sources: Geoapify Places API, OpenStreetMap contributors (ODbL)
Registered sex offender counts within defined radii. Only aggregate counts are displayed - no names or personal information.
Sources: State and local sex offender registries
Additional sources on reports
Beyond the core public-record categories above, individual report sections may include:
- HUD Small Area Fair Market Rents (SAFMR) — U.S. Department of Housing and Urban Development, HUD User FMR datasets.
- Flood hazard — FEMA National Flood Hazard Layer via the FEMA Flood Map Service Center.
- Eviction filing statistics — DC reports use the DC Office of the Tenant Advocate monthly eviction data; Maryland reports use the Maryland Judiciary District Court eviction case dataset; Virginia reports use LSC Civil Court Data. The legacy fallback for uncovered areas is Princeton Eviction Lab tract-level data; fallback tract location uses the FCC Census Block API.
- Neighborhood demographics and commute — U.S. Census Bureau American Community Survey (ACS); county unemployment may include BLS Local Area Unemployment Statistics (LAUS).
- Schools — proficiency and relative standing come from state report-card sources: Maryland Report Card, Virginia School Quality Profiles, and DC School Report Card. Assigned schools use district boundary services where integrated: DCPS EBIS, MCPS, PGCPS School Finder, FCPS Boundary Locator, Loudoun County Public Schools, and Arlington Public Schools. NCES CCD/EDGE is used only for nearby school context or fallback directory/location data, not as the preferred assigned-school authority.
- Apartment ratings and gym listings — when API keys are configured, business listings and ratings from the Yelp Fusion API (Yelp branding appears next to that content on reports).
- Management company complaints — Consumer Financial Protection Bureau Consumer Complaint Database (aggregate counts and links only).
- Neighborhood map (satellite) — Esri World Imagery tiles; attribution is shown on the map control (Esri, Maxar, Earthstar Geographics, and OpenStreetMap contributors as applicable).
- Affordable housing — Three sources combined: HUD LIHTC Database (federal Low-Income Housing Tax Credit properties), Montgomery Planning MPDU (county Moderately Priced Dwelling Units), and DC Open Data Affordable Housing.
- Transit proximity — Nearest Metro stations and bus stops from the WMATA Developer API covering all DMV jurisdictions.
- Internet options — Provider-reported fixed broadband availability at or near the geocoded report coordinate, sourced from the free Broadband Map API built on FCC National Broadband Map / Broadband Data Collection-derived public availability data. Reports show this in building verification with wired internet options, technology, and maximum advertised speed where available. This does not confirm unit wiring, actual performance, building bulk internet, installation timing, or plan price; renters should verify those with the leasing office and provider.
- Rent vs nearby — RentSift compares a matched building's listed rent to the same unit type in RentSift's ZIP aggregate from daily apartment snapshots. This is RentSift market context only; it is separate from HUD Fair Market Rent and separate from the ZORI trend map.
- Air quality — Current AQI observations from the EPA AirNow API.
- Rental licensing (Montgomery County) — License status from MoCo Housing Licensing & Registration.
- Lead paint risk — Based on the building's original year built in government property records. EPA / HUD disclosure rules apply to most pre-1978 housing; reports flag those buildings and explain when a later update year likely means remodel or tax-record updates rather than original construction.
- Smoking policy — Jurisdiction-specific enforcement information sourced from DC Law 22-260, Montgomery County Code §24-9, and state-level legislation for MD and VA.
- Owner, sale, and building records — Official property-record sources: DC CAMA / Owner Polygons, Maryland SDAT, Fairfax County Tax Administration ArcGIS, Arlington County DataHub, and Loudoun County GeoHub. Listed owners are shown only where the official source provides them; sales and property tax values stay in the property section, not the landlord-management section.
- Construction activity (Fairfax County) — Building permits and active construction from Fairfax County DevelopmentTracker.
- Housing inspection violations (PG County) — Inspection violations since 2014 from PG County Open Data.
How to read report signals
RentSift is designed to show source-linked records and renter questions, not a proprietary safety verdict. Some sections may include source-specific metrics, such as Walk Score, school assessment context, HUD REAC scores, or count-based summaries. Those metrics are supporting context, not a certification that a building or neighborhood is good, bad, safe, or unsafe.
| Category | Scope | What it measures |
|---|---|---|
| Safety | Nearby | Reported incidents near the searched pin, ranked with close-distance, severity, and recency weighting. Public block-label matches use the source's block text; distance-band rows use published map coordinates when no block-label match is available. Both are nearby context, not exact-building evidence. |
| Code & complaints | Property / nearby | 311 complaints, code violations, and housing inspections split by address match or nearby context where possible |
| Walkability | Area | Walk Score, transit access, bike context, and nearby destinations where available |
| Schools | Assigned / nearby | Assigned district schools, current state assessment context within each school's own state system, and nearby school directory context where available |
| Utilities | Area / provider | Source-backed utility budget ranges and provider context where public data supports it |
| Internet options | Provider-reported | Shown under building verification. Broadband Map API lookup built on FCC BDC availability near the report coordinate; verify in the FCC map; not a guarantee of in-unit wiring, installability, actual performance, bulk-building rules, or plan price |
| Rent vs nearby | ZIP / property | Matched building listed rent compared with RentSift's daily ZIP aggregate for the same unit type, separate from HUD FMR and separate from the ZORI map |
| Possible monthly add-ons | Property / effective jurisdiction | The report shows one planning range after HUD FMR that combines RentSift rent and utility data when available with conservative market-fee ranges and official local rules. It is an estimate, not the property's quote. Census incorporated-place and county-equivalent geography can route Maryland municipalities away from generic county assumptions and keep Virginia independent cities such as Falls Church, Fairfax City, and Alexandria from being mislabeled as county addresses. |
| Next checks | Hero action summary | A short list inside the report hero for items that need confirmation or review before applying. Clear or strong sections stay in their supporting report areas. It is not legal advice, a safety rating, or a guarantee of current conditions. |
| Neighborhood | Area | Census and local context such as demographics, commute, and public-record coverage limits |
| Grocery access | Nearby | Grocery stores, pharmacies, convenience stores, parks, and gyms near the address |
| Lease questions | Action | Practical questions generated from the records shown in the report |
If a data source is unavailable or returns no results, that signal is marked as missing, unavailable, or no matching record rather than treated as proof that no issue exists.
Findings closer to the searched address are prioritized in the report, but nearby public records remain context only unless the source supports an address-level match.
Data freshness
Reports are generated from live API calls at the time of request. Data freshness depends on how frequently each source agency updates their datasets (typically daily for crime and complaint data, and monthly for utility rate information). Fairfax County police context uses the latest downloaded weekly CSV when it is fresher than the FCPOD ArcGIS crime layers, and the report labels that shorter window directly.
Reports are cached for a limited period to reduce load on source APIs. The cache status is displayed on each report.
Important disclaimer
RentSift reports are provided for informational purposes only and do not constitute real estate, financial, legal, or investment advice. Data is sourced from publicly available government databases and third-party providers. We do not guarantee the accuracy, completeness, or timeliness of any information presented.
Users should independently verify all information before making rental or housing decisions. RentSift shall not be liable for any direct, indirect, incidental, or consequential damages arising from use of this information.
This product uses the Census Bureau Data API but is not endorsed or certified by the Census Bureau. Geographic data includes information from OpenStreetMap contributors, available under the Open Database License.
Walk Score®: When displayed, walk, transit, and bike scores are provided by Walk Score (Smarter Travel Media LLC) under their API terms. Walk Score is a registered trademark of Smarter Travel Media LLC.
Yelp: Ratings and business listings sourced from Yelp are subject to Yelp's API terms; we show "Powered by Yelp" next to that content.
Geoapify: Grocery, pharmacy, park, and gym data is powered by the Geoapify Places API, which uses OpenStreetMap data. Geoapify is not affiliated with RentSift.
HUD, FEMA, and eviction sources: Fair market rent figures cite HUD SAFMR; flood zones cite FEMA; eviction statistics cite their active public source in the report: DC OTA, Maryland Judiciary, LSC Civil Court Data, or Princeton Eviction Lab fallback. These agencies and projects are not affiliated with RentSift.
Metrics, counts, and projections reflect data available at the time of report generation and may not reflect current conditions. Utility cost projections are estimates based on state-level average rates and consumption and will vary by household.
School proficiency data is sourced from official state Department of Education publications: Virginia Standards of Learning (SOL) pass rates from schoolquality.virginia.gov, DC OSSE School Report Card Assessment scores from osse.dc.gov, and Maryland MCAP ELA & Math proficiency rates from reportcard.msde.maryland.gov. All data reflects the 2024-2025 school year. Proficiency metrics vary by state and are not directly comparable across state lines. Assigned-school boundaries come from district boundary services where available, including DCPS EBIS, MCPS attendance zones, FCPS Boundary Locator, Arlington Public Schools boundaries, and Loudoun County Public Schools zones. NCES CCD/EDGE public school locations are used only for nearby context or fallback, not as the source of assigned schools.
Tenant rights information, including rent stabilization caps, renewal policies, application-fee caps, security-deposit limits, late-fee limits, and cost guardrails, is sourced from official government websites and Census incorporated-place geography where city boundaries affect the rule set. Current cost sources include DC OTA/Rental Housing Commission, DC Code, Montgomery County DHCA, Prince George's County PRSA policy, Takoma Park, Rockville, Gaithersburg, Mount Rainier, Maryland Real Property law, and the Virginia Residential Landlord and Tenant Act for Fairfax County, Arlington, Loudoun County, Alexandria, Falls Church, Fairfax City, and other supported Virginia reports. Guardrails do not replace a building's lease, application packet, or written fee schedule. Laws and regulations change frequently. RentSift does not provide legal advice. Consult an attorney or your local tenant rights office for guidance on your specific situation.
A note on 311 complaint data: 311 complaint counts reflect what residents have reported, not necessarily the full extent of conditions at a location. Research has shown that 311 reporting rates vary by neighborhood, with some areas systematically underreporting issues. An address with zero complaints does not guarantee the absence of problems — particularly in areas with lower reporting rates. We present complaint data as one signal among many, not as a definitive assessment of building conditions.
Environmental compliance data is sourced from the EPA Enforcement and Compliance History Online (ECHO) database, which tracks facilities regulated under the Clean Air Act, Clean Water Act, and Resource Conservation and Recovery Act.