Pricing an Antioch house starts with defining the property that a buyer would actually receive. A house with accessory accommodation, a recently built detached home and an attached home with shared obligations can compete for attention without belonging in one interchangeable price-per-square-foot calculation. Comparable evidence needs to describe both the property and the completed transaction.
This article develops the pricing questions in the Antioch guide through a local evidence-screening exercise. It contains zero verified closed-sale observations and no current value opinion. A permissioned transaction dataset and first-hand broker analysis were not supplied. The original worksheet below shows how actual public project records can identify questions to resolve before admitting any property into a sale comparison.
State the pricing question before drawing a search boundary
Describe the subject’s verified accommodation, site, condition, completed changes and ownership obligations first. Identify what remains uncertain. If the subject includes a separate kitchen or converted space, resolve its documented status and current use rather than allowing an attractive total room count to define the comparison. A change in that description can change the relevant competing properties.
Then give the proposed search a date, geographic boundary and property criteria. Explain why that area and property group represent meaningful alternatives for the subject’s likely buyers. A nearby closing is a lead, not proof of similarity. Conversely, a more distant sale may deserve investigation if it offers a much closer match to an unusual documented feature.
As one professional reference, Fannie Mae’s comparable-sales guidance emphasizes similar physical and legal characteristics and requires explanation when appraisers use competing market areas. Its appraisal guidance is not an appraisal performed here or a promise about a particular loan. It illustrates why a meaningful comparison needs a stated rationale beyond proximity.
Keep Antioch’s city boundary distinct from the comparison boundary. If an investigator expands into another community, label that expansion and explain the differences being considered. Do not silently rename a wider search as an Antioch sample. A countywide trend can supply context while remaining too broad to establish the price response to one property’s layout or ownership duties.
Three real local leads show different evidence gaps
The City’s March 18, 2026 packet includes a 2025 issued-permit table with 40 W. Madill Street, Unit A, ADU2025-0039, and 5400 Riverview Lane, B2024-2502, for a new detached house. These entries identify accommodation and construction questions to investigate. They do not provide verified closing prices, current condition or proof that either project is presently complete.
A different lead is the Wildflower Station Townhomes 2 notice posted November 7, 2025. It records tentative-map and design approval for 159 planned units, including row and back-to-back designs, with proposed private roadway and common-area parcels. Planning approval is not evidence of today’s available homes, final recorded ownership terms or a completed sale.
These distinctions affect sample design. A lead with accessory accommodation needs evidence about that accommodation. A new-house lead needs evidence of completion and actual transaction terms. A townhome lead needs the current unit’s legal and maintenance arrangement. The project label helps identify follow-up questions; it cannot supply the missing answer or establish a price premium.
Do not transfer a neighboring phase’s features to the named phase or a subdivision’s marketing description to an individual house. Confirm the actual address, parcel and relevant unit. Record whether a description comes from a proposal, an approved plan, a completion record or a current observation. Those stages can describe materially different things even when the project name stays the same.
Original Antioch comparable-evidence admission worksheet
Research date: October 26, 2026. Verified closing sample: zero. These are public record leads, not sales, valuations or current listings.
| Public lead | Question it exposes | Evidence still needed for a sale comparison |
|---|---|---|
| 40 W. Madill Street, Unit A | ADU permit entry; establish actual accommodation and completed scope. | Candidate identity, current configuration, completion, closing date and price, terms and condition. |
| 5400 Riverview Lane | New detached-house entry; separate issuance from completion. | Actual house and site, settled transaction, included upgrades and any verified concessions. |
| Wildflower Station Townhomes 2 | Approved planned mix; distinguish row and back-to-back design and common parcels. | Current completed unit, recorded rights, maintenance duties, actual closing and financial terms. |
For each proposed comparable add the permitted data source, effective research date, contract and closing dates, verified price, actual property description, material differences, reason for inclusion or exclusion and evidence supporting any adjustment. Leave an unknown blank with an assigned follow-up; do not enter zero to imply no difference.
Assemble a transaction file with permission and dates
For a real pricing study, disclose which source supplies each transaction field and whether the information can be published. An internal professional research file and a public article need not expose the same material. Retain enough information for the authorized reviewer to reproduce the selection and reasoning without publishing private statements or protected data.
Separate a confirmed closing from an asking price, pending contract or project estimate. If a field is unavailable, record the limitation and determine whether the observation remains useful. Do not turn an unavailable concession amount into an assumed zero or an unknown condition into an average-condition classification. Such shortcuts make a numerical comparison look more complete than its evidence.
Keep contract date, closing date and pricing date distinct. A closing records a completed transaction, but the agreement may reflect decisions made earlier. Ask the reviewing professional how the actual timing affects the comparison. Do not automatically apply a broad annual percentage to every sale regardless of its agreement date or its property group.
Verify upgrades before arguing for an adjustment
Antioch’s online permitting system supplies the City route for relevant building, planning and inspection research. Use it to connect a represented change to its actual scope and completion evidence. A report entry for one improvement cannot validate all advertised work or establish how the improvement performed when a different property sold.
A renovation invoice answers what was purchased, while a sale comparison asks how buyers responded to the resulting property. Do not recover every improvement cost automatically through a price adjustment. A contractor’s proposed cost also does not establish the market discount for an unresolved issue. Those are separate quantities requiring different evidence.
Fannie Mae’s adjustment guidance calls for market-supported reasoning and addresses transaction concessions and timing. For this article, the appropriate application is to ask what supports a proposed adjustment. No dollar-per-foot rule, ADU premium, renovation recovery percentage or Antioch time adjustment has been established by the available research.
Where the evidence is thin, present the disputed feature explicitly and ask for additional observations rather than inventing a precise correction. A supported explanation of uncertainty is more useful than a polished grid built from arbitrary numbers. The reviewer should be able to distinguish a measured difference, its proposed market effect and the evidence connecting the two.
Compare usable rights and obligations alongside design
Contra Costa County’s Maps and Records page provides access to recorded maps and annotated parcel books. It also cautions that a subdivision map need not show every easement affecting a property. A project’s planned private roadway therefore calls for current title and governing-document investigation rather than an assumption about unlimited access or owner maintenance.
For an attached-home comparison, document the actual interests conveyed and which components are maintained collectively. For a detached home, verify any shared access or recorded obligation rather than assuming sole responsibility from appearance. Compare the scope of payments and maintenance, not just the amount of a quoted due. This article establishes no particular association’s reserves, insurance or financial condition.
Separate current utility of a completed feature from a proposed future change. If a buyer values possible accessory accommodation, obtain the current feasibility and cost evidence for that scenario. Do not compare an unapproved possibility as equivalent to an existing, documented and usable improvement. Keep the future project assumption outside the current-property description.
Use the reviewed evidence to make the pricing decision
A completed professional analysis should state its effective date, source permissions, search period, included observations and reasons for exclusions. It should explain why particular evidence receives more weight and where an unresolved difference limits confidence. No completed dataset, broker-authored adjustment or numerical price range is supplied here.
Sellers can prepare verified work, accommodation and ownership records before the pricing meeting; buyers can request the same evidence before relying on a competing sale. Refresh the analysis when new transactions or material documents change the comparison. The selling process and Contra Costa County guide provide the wider transaction framework while the actual local evidence supports the eventual decision.
