Methodology

It is not an inspection. Nobody has looked at the pipe. BelowGrid reports what official sources record, and records are not the same thing as condition.

It is not legal advice. A requirement shown here is reported as the authority states it. Whether it applies to a particular transaction is a question for that authority.

An absence of records is never good news. When BelowGrid shows nothing, that is a statement about the sources it can see. It is not evidence that nothing exists, and it is never evidence about the property.

A submitted address is matched against a geocoding provider and, where more than one candidate is plausible, the choice is presented rather than made. Choosing wrongly would show somebody else’s property, which is the most damaging error this product can make.

The chosen candidate is carried forward by identifier, never by re-parsing the text that was typed.

Every authority is resolved by a spatial match against its published boundary, not by the postal city on an address. Sewer service areas and municipal lines do not agree, and a postal city is often neither.

A property sits under several authorities at once: a city, a county, sometimes a regional programme. Each may impose its own requirements, so all of them are resolved and all of them are shown.

Boundaries come from the U.S. Census Bureau TIGER/Line files. Where BelowGrid cannot confidently determine an authority, it says so rather than guessing from the city name.

Every requirement is quoted from a document, and every page links the document so you can read the sentence yourself. That is the check this site offers.

Most of it was researched and written by software working to a fixed method, and for most answers nobody at BelowGrid has read the source document. That is precisely why every claim is quoted and every quotation is linked: the document is the check this site offers, not our sign-off on it. Nothing is published without a source you can open.

Rules are evaluated with three outcomes rather than two: applies, does not apply, and cannot be determined. Where a rule depends on a fact BelowGrid does not hold — a construction year, a use class — the answer is that it could not be confirmed. A missing fact never becomes “this does not apply to you”.

Where two authorities disagree, both are shown and neither is chosen. BelowGrid reports a conflict; it does not resolve one.

Coverage measures how much of the record BelowGrid can see for a property. It is not a risk score, and it says nothing about the condition of anything underground. A property with excellent coverage may have a failing lateral; a property with limited coverage may be in perfect order.

Eight categories are weighted and summed. Where the identity of the property or its service provider is uncertain, the score is capped rather than reduced — a high score assembled against a possibly-wrong authority invites confidence the evidence does not support.

The label is a band rather than a number, because a number reads as precision the underlying data does not have. Every category is listed on the page, including the ones with nothing in them.

A finding cannot exist without a source. That is enforced in the code, in the database, and in the published API contract: there is no path that produces an unsourced claim about a property.

Findings are distinguished by kind. “A rule applies to properties like yours” is shown differently from “here is a record about your property”, because they are different claims.

It will be, and the honest thing is to say how you can tell. Every statement links to the document it came from. If the document says something different, the document is right.

Report a correction and it will be checked against the source.