About HouseLines

What is HouseLines?

HouseLines is a property genealogy platform. We organize public building records — permits, renovations, contractor activity — and present them in a format that's actually useful to homeowners, buyers, and curious neighbors.

Every day, thousands of building permits are filed with municipal governments across the country. These records are public, but they're scattered across dozens of town portals, PDF directories, and outdated databases. HouseLines brings them together.

Methodology

Our data comes from public municipal sources: town building departments, assessor databases, and state-level permit tracking systems. We normalize, clean, and aggregate this data to create town-level snapshots of building activity.

• Permit data: Sourced from municipal building departments and online permit portals (ViewPoint Cloud, VGSI, MapGeo).
• Housing data: Derived from town assessor databases and parcel records.
• Rebate data: Curated from Mass Save, utility company programs, and municipal incentive pages.
• Contractor rankings: Based on permit filings — reflects permit activity, not necessarily all work performed.

Data is updated on a regular cadence. Permit counts may lag by 1–2 months depending on municipal publishing schedules.

Data Sources

We currently track data from Massachusetts towns that use publicly accessible permit management systems, including:

• ViewPoint Cloud (OpenGov) — Building permit applications and tracking
• VGSI — Assessor database and property records
• MapGeo (GIS) — Parcel mapping and spatial data
• Mass Save — Energy rebate and incentive programs
• Municipal building department websites

Accuracy & Caveats

While we strive for accuracy, there are important caveats:

• Not all work requires a permit. Minor repairs, painting, and some replacements may not appear in permit records.
• Contractor names on permits reflect who pulled the permit, not necessarily who performed the work.
• Permit valuations are self-reported and may not reflect actual project costs.
• Data may have gaps due to municipal recordkeeping practices.

Always verify with local authorities before making decisions based on this data.

What's Next

We're actively expanding to more Massachusetts towns and developing address-level reports that will give homeowners the complete permit history for any property. If you'd like early access to address-level reports, get in touch.