When a Brentwood home includes an addition, converted room or accessory unit, begin with a narrow question: what work was approved, and what evidence shows it was completed? The answer rarely fits into a single permit number. Applications, approved plans, issued permits and inspection records describe different stages. A useful research file connects those stages to the space you see today. The Brentwood property guide explains why later changes matter; the City’s public ADU register provides concrete examples of how to investigate them.
This walkthrough uses actual published records checked October 26, 2026. It does not represent an inspection, a review of the complete private building file or a determination that any listed unit is ready for occupancy. Its purpose is to show how a buyer or seller can organize the available evidence, identify missing records and ask a useful question of the correct City reviewer.
Start with the parcel, scope and reviewing agency
Match the property address to a parcel reference before collecting improvement records. The County’s Maps and Records page links parcel and recorded-map research tools, while explaining limitations of available map information. A Brentwood mailing address alone should not replace jurisdiction confirmation. For an actual City parcel, Brentwood’s Development Services and Planning routes supply the relevant starting points; County materials for unincorporated improvement plans are not automatically the permit file for that City property.
Then describe the change precisely. An enclosed patio, a new detached unit, an altered electrical system and a roof replacement create different record searches. The City’s electronic submittal page separates new residential work from miscellaneous residential changes and electrical, plumbing and mechanical work. Its categories include additions, remodels, patio covers, pools and roofs. Search the actual scope rather than assuming that a general remodeling entry explains every visible improvement.
Read application, approval and issuance as separate events
Consider 633 Third Street. The City ADU register lists B26-0466 with a March 19, 2026 application date, June 9 approval date and June 22 issuance date. The listed area is 749 square feet, and the entry appears in the under-construction group. A file note can accurately reproduce that sequence. It should not turn the June issuance into a final-inspection date or describe the published area as verified completed living space.
At 720 Bramhall Street, the same register lists two under-review applications: B26-1057 for 749 square feet and B26-1072 for 499 square feet, applied for on successive days in July 2026. Keep both numbers in the research file. The table does not establish that these entries represent two approved, independently usable homes. It also does not identify every legal distinction that might matter between an ADU, another accessory configuration and the owner’s proposed scope. Approved plans and the City’s explanation are needed.
A blank field also has a limited meaning. The under-review entry B26-1581 at 1764 La Pergola Drive shows a September 28, 2026 application but no size in the published table. Record the size as unavailable in that source. Do not borrow an area from a nearby address, a model plan or a listing photo. An honest missing-data field gives the next reviewer a clear task; an invented number can contaminate the entire property comparison.
| Published example | Record sequence | What to annotate next |
|---|---|---|
| 633 Third Street / B26-0466 | Applied March 19 → approved June 9 → issued June 22, 2026; 749 square feet; under construction. | Attach approved plan revision; identify final inspection and occupancy evidence. Issuance is not completion. |
| 720 Bramhall Street / B26-1057 and B26-1072 | Applied July 1 and July 2, 2026; 749 and 499 square feet; under review. | Separate applications and proposed scopes. Do not combine them into approved living area or independent dwelling rights. |
| 717 Dainty Avenue / B22-3192 and B24-0636 | 997 and 492 square feet; separately approved and issued in 2023 and 2024; under construction in register. | Match each number to its own plan and inspection record; ask whether the public stage remains current. |
| 1764 La Pergola Drive / B26-1581 | Applied September 28, 2026; size field blank; under review. | Leave area unknown until a reliable property-specific source supplies it. |
Source: City ADU register. Reusable file fields: parcel / existing configuration / application number / scope / approved revision / issuance / inspection dates / final status / unresolved discrepancy / reviewer and response date. No private plans or inspection findings are reproduced.
Keep multiple permits attached to their own scope
The two construction-stage entries at 717 Dainty Avenue illustrate why a chronological file matters. B22-3192 lists 997 square feet, applied for in December 2022 and approved and issued on October 24, 2023. B24-0636 lists 492 square feet, applied for in April 2024, approved July 2 and issued July 22, 2024. Different dates and areas belong to different entries. Neither the age of an issued permit nor the number of entries proves the current physical arrangement.
Compare the plan sheets with the actual room arrangement, exterior footprint and service connections through appropriate professional review. Note whether a visible wall, door or converted space corresponds to the approved revision. If the arrangement differs, write down the difference without deciding from photographs that it is compliant or defective. Ask the owner for the relevant documents and ask the City which record or review would resolve the discrepancy. That produces a specific next step instead of an unsupported conclusion.
Retrieve the full file through the available route
A further example shows why the retrieval date matters. At 723 Anderson Avenue, B26-0262 appears in the actual current register under construction, with September 10, 2026 approval and September 14 issuance. An older search copy had presented it under review. Keep the newer actual City record and its checked date in the file, and distinguish it from the older indexed copy. This does not establish when the page changed, whether construction has physically advanced or whether final inspection has occurred.
Create a separate observation column when reviewing an actual candidate. One column should reproduce the source’s words and dates; another should describe what an authorized visit or qualified inspection actually found. A third should identify the unresolved connection between them. For example, an issued ADU permit may describe a size while an inspection identifies unfinished systems. Those facts can coexist. The task is to obtain completion evidence and understand remaining work, rather than forcing all information into a simple permitted-or-unpermitted label.
For converted space, ask for records that describe the specific conversion. A roof permit does not resolve whether a garage room was approved for the use described in marketing. Likewise, a later electrical permit may establish one system change without documenting a floor-plan alteration. Brentwood’s separate work categories make that distinction practical: list each visible change, connect it to the relevant scope and record any gap. The resulting questions help the City, the owner and the appropriate professional concentrate on the same part of the property.
During research, the City’s linked electronic permit search redirected to a public or contractor login screen. No account was created and no private record was accessed. The public ADU register therefore supplies the examples here, while the complete approved plans and inspection history remain outstanding. A limited public search is not evidence that other permits do not exist. Use the City’s current records route and obtain the owner’s copies when available.
The January 2026 development-services application matrix is useful for organizing a proposed change. It distinguishes work categories and the materials associated with them. Read the appropriate row and confirm the scope with staff rather than collecting every item in the entire matrix. Engineering may also have a separate role where grading, drainage, driveway work or connections touch public improvements; the Development Engineering page describes that review path.
Check the current planning document before designing the next change
Brentwood’s Current Planning page reports that residential objective design standards were adopted July 28, 2026. Retrieve the applicable adopted material and property conditions before relying on an older handout or a draft found in a search result. This article does not interpret those standards for a particular project. It identifies why the date and status of a planning document belong beside its title in a pre-project file.
For a seller, assemble a concise chronology showing which improvements have supporting approvals and completion records, and which questions remain open. For a buyer, align the document review with the purchase investigation timeline before treating a room or potential unit as essential to the decision. Keep broader jurisdiction questions with the Contra Costa County guide. The most useful result is a file that connects the actual property to the actual approval and gives the next qualified reviewer a question they can answer.
