Blog · October 14, 2026 · Pennsylvania
Brentwood Plat Map, Pennsylvania: plats and lots
A recorded plat shows how land near Whitehall was divided into lots.
Main page: Allegheny County, PA GIS & Parcel Viewer (official map link, county facts and neighboring maps).
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When a listing near Mount Oliver mentions a lot number, look up the Brentwood plat map it refers to. In this Brentwood guide: where to request a copy, plat versus tax map, and the details that matter to buyers.
Getting started with the Brentwood plat map
For land around Castle Shannon, look for the plat book reference on the parcel record; use it to request a copy.
Where the parcel data lives
Go first to the Allegheny County ArcGIS parcel map; it covers every tax parcel around Dormont and Castle Shannon. For property near Mount Oliver, enter a street address, an owner's name or a parcel number, and the viewer zooms to the match. For a tract near Baldwin, the record panel normally shows the owner of record, acreage on the tax roll, the parcel number and often a sale date.
Using it on a phone
The parcel map usually runs in a mobile browser, which helps when you're standing on land near Baldwin, but coverage can be spotty out of town. A printout of the tract near Whitehall helps when you meet an owner or agent.
Where Brentwood fits in
Brentwood sits in Allegheny County, Pennsylvania, which means parcel data comes from the county. Out toward Pleasant Hills, the municipality handles things like zoning, permits and utilities for lots inside the boundary, and the county still keeps the parcel and deed records. Land beyond the city limits toward Pleasant Hills generally follows county rules rather than the town's.
When a parcel crosses a boundary
Allegheny County touches Armstrong County, Beaver County, Butler County, Washington County, and Westmoreland County; every one of them runs a separate parcel map. A tract near the line by Mount Oliver can be split in two county records, so look at the adjacent map too. Closer to Castle Shannon, our state page links every bordering county map across Pennsylvania.
How land is described here
Older tracts around Mount Oliver are often described by metes and bounds, listing bearings, distances and landmarks. Platted lots around Dormont are typically described by lot and block, making them easier to find. Write down the legal description for the tract near Baldwin for any title or survey request.
Metes and bounds instead
Rural land near Mount Oliver that was never subdivided is often described by metes and bounds or survey description; the deed and any recorded survey describe it instead.
When a plat changes
An amended plat may change lots around Dormont, so check for later filings; street vacations near Baldwin show up in the records too.
Offices that can help
For assessment questions about property around Baldwin go to the county assessment office, since that office keeps the assessment data. Building or septic questions for a lot near Whitehall are for the local planning and health departments, and the answer depends on jurisdiction.
Two different maps
When the two disagree for a lot near Castle Shannon, go with the plat and a surveyor's work.
Allegheny County in a few facts
Pittsburgh holds the county offices, where most land records are kept. You'll also find Whitehall, Baldwin, Castle Shannon, and Mount Oliver, where town lots give way to larger tracts. Roughly 1,224,825 people call Allegheny County home (Census Bureau estimate, 2023) on roughly 730 square miles. Allegheny County was organized in 1788, so old deeds can run back a long way. Features like Allegheny River and Monongahela River are easy to spot when you zoom out from Baldwin.
Details on the Brentwood plat map
Near Dormont, the sheet usually includes lot and block numbers, dimensions and bearings, street rights-of-way and easements.
The paper trail behind a parcel
The map is an index, not the title: recorded deeds, subdivision plats and easements covering ground around Dormont are filed with the Recorder of Deeds. Long-held tracts near Castle Shannon can sit on a long string of deeds, and a title company earns its fee on a real sale.
Getting a copy
For land near Baldwin, some counties put plat images online, while others require a visit or a request; copy fees are usually small.
A word on accuracy
Parcel lines are drawn for taxes, not surveyed, so a tree line near Castle Shannon can sit several feet off the line on screen. For property near Mount Oliver, owner names and values update on a schedule, so a deed recorded last month may not show yet.
Brentwood: common questions
Who has recorded plats for land near Dormont?
In most cases, recorded plats near Pleasant Hills are filed with the Recorder of Deeds.
What is a lot and block description for land near Castle Shannon?
For land near Dormont, the description sends you to a specific recorded plat, so pull that plat for dimensions.
What is a replat around Baldwin?
It depends, but combining or splitting lots near Mount Oliver usually needs a recorded plat change, often with a surveyor's drawing.
Are old plats online in Brentwood?
It depends, but older plats near Baldwin may be on film or paper.
Where is the legal description for land near Pleasant Hills?
For a tract near Mount Oliver, Deeds use lot and block, metes and bounds or survey descriptions, and the parcel record often summarizes it.
Open the official Allegheny County, PA parcel map See it in the Platbookmapper directory
Not a survey. County GIS and tax parcel maps are assessment and planning layers. They are not a substitute for a recorded plat, deed, or licensed survey, especially for fences, setbacks, or boundary disputes.