Before a rep knocks, Driveway Radar pulls what is knowable about the address. This page documents where that data comes from, how every line on the card is labeled, and the sentences the tool is built never to say.
Sources: Driveway Radar Design and Driveway Radar Build Report, November 2, 2026; caps and retention as implemented in the member platform.
The sources
Property data comes from the RentCast API: public-record property facts (year built, last sale on record, living area) and a value estimate. Storm history comes from NWS Local Storm Reports served by Iowa State University's Iowa Environmental Mesonet (IEM) — free, public, point-level storm reports, plus archived storm-warning polygons, so Radar can state that an address sat inside a warning polygon on a given date.
The value figure is shown as a labeled estimate range, and the card says on its face that it is not an appraisal. Data that is missing renders as an honest gap — a sale figure not published in a state is shown as not published; an empty storm history is shown as no reports near the address, never as proof of no storms.
The labels
Every line on a Radar card is one of two kinds, and labeled as which. A RECORD is a field the provider or the Weather Service returned: built 1998; hail of 1.25 inches reported 1.8 miles from this address on a named date. A READ is Spar's inference from records — a hypothesis to verify at the door, labeled as one: pre-1990 build, expect original systems; verify in Probing & Layering.
The guardrail sentence structure is fixed. Radar may say hail was reported near this address, with the distance and the date. It may never say this house was hit by hail, or that this roof is damaged. And there is no equity figure: the property source carries no mortgage or balance data, so no honest per-address equity number exists at this level — Phase 1 shows none, rather than a modeled one dressed up as a fact.
The guardrails in code
Radar is capped at 50 fresh pulls per member per month, enforced in the platform's configuration; a pull served from the shared address cache does not count against the cap. Results are cached per address for 30 days — reps work the same storm streets, and one member's pull serves the next rep on the block. A member's Radar history purges on a rolling 90-day basis, and a member can delete their own lookups at any time.
The last guardrail is doctrine, and it comes from the founder's Entry lesson: Radar is an approach tool, never a skip tool. The card carries no skip-this-house output and no ability-to-pay verdict; whatever the card shows, the game plan it builds ends the same way — run the documented process, and never prejudge the homeowner from the house, the street, or anything noticed on arrival.
Sources: Driveway Radar Design, November 2, 2026; Driveway Radar Build Report, November 2, 2026; member platform configuration (pull cap, cache, retention).
Driveway Radar rides with the full camp — 20 rounds, the scorecard after every one, and a card for the next address. Round 1 is free; membership is $29/month. Spar before you knock.