For property inside the City of Monrovia, California, start with the work year. The City’s About My House page points to a separate 1911–1947 Permit Book for early building-permit information and to OnBase for many building permits and planning-approval documents. If the document you need is not online, the City offers a public records request. These are different routes to evidence, not a single complete property-history search.
Which Monrovia record should you open first?
- Work between 1911 and 1947: open the Permit Book linked from About My House. Save the book entry, year, original address wording and any permit reference.
- A later permit or planning approval: use the City’s OnBase Document Portal. Keep the document date, type, address and permit or case reference.
- A known document absent online: make a City records request with the street address, likely date range, work type and document sought.
The year is a routing clue, not a promise that every permit from that period survives or sits only in one source. A book entry and a later digitized document can describe different work on the same property. Save both with their dates instead of merging them into one project.
Search OnBase with the address pieces the City uses
The City’s Browse Documents Online page says building permits can be found with search words or by browsing folders in OnBase. The City’s linked OnBase public-access form defaults to Building and Planning and separates Street No, Street Direction, Street Name, Street Suffix and Apt/Suite/Unit. It also shows From Date, To Date and Project Name fields.
Start with the street number and name as the City records them. Add a direction, suffix or unit when they distinguish the property; keep an alternate address spelling to try if an older document uses it. Narrow by date only when you have a credible work period. If a document appears, record its title, date, address and any permit or planning case number before drawing a conclusion from it. A search form alone does not show how complete the scanned collection is.
For a house with a possible 1930s alteration, use the Permit Book first and note the exact entry. Then use OnBase for later permits or approvals that may explain subsequent changes. A county assessor’s construction year, which the City also links from About My House, can help frame the question; it is not proof of a particular City permit.
If the house is one of Monrovia’s landmarks
The City’s About My House page says Monrovia has more than 150 historic landmarked homes, from Victorian and Craftsman to Ranch and Mid-Century. Landmark status adds a second paper trail. The designation itself, and any later Planning review of changes to a landmark, are planning records, so search OnBase under Building and Planning for both permit and planning documents, and name the landmark file in a records request if it doesn’t appear.
The same City page sends readers to the Monrovia Historic Preservation Group, a private group, for a list, map and photos of historic homes. Its research can point you to a construction year or original builder. It is not a City record, so use it to narrow your Permit Book or OnBase search, not as permit evidence.
Two other City-linked tools answer different questions. The Interactive Zoning Map shows how a parcel is zoned today, which says nothing about whether past work was permitted. The Los Angeles County Assessor lists lot size, construction years and number of units; a unit count that differs from what you see on site is a reason to look for a permit, not proof that one is missing.
When the online trail stops
An empty OnBase result does not establish that no permit or approval existed. The City says its system holds documents that have been scanned and that records unavailable in the imaging system can be requested through the City Clerk’s public records process. For building or property records, the City asks requesters to include the address and street name. Include the likely year or range, the type of work, and any reference copied from the Permit Book or another City document. Ask for the specific permit, plan or planning decision you need rather than an undefined complete history.
If you do not know when the work occurred, describe what changed and the evidence you have instead of guessing a permit year in the request. For a document that OnBase did not return, use the City’s records-request route. Keep a short log of the book years, OnBase terms and request made so a missing online result is not mistaken for an agency finding.
A permit-book entry shows recorded permit information for its period. A permit document shows the scope and event described in that document. Neither alone establishes completion, final inspection, the absence of later alterations, or approval for a present use. If completion matters, follow the permit number into any available inspection and final records; our final-inspection guide explains that separate check. If the address may fall outside Monrovia City, resolve the issuing jurisdiction before treating a City search as complete; our city-versus-county guide covers that first decision.
City of Monrovia About My House, Browse Documents Online and public records pages checked October 20, 2026.