Build a comparison around the property people would actually buy
A San Anselmo home can have a familiar address, attractive interior photographs, and a generous parcel area while offering a very different ownership experience from the next house. A steep approach, outdoor areas on several levels, a creek setting, or an uncertain history for a converted space can change which properties deserve comparison. Starting with a townwide price per square foot conceals those differences before the research begins.
This article provides an original research framework for selecting and checking comparable sales. No permissioned MLS export, verified settlement file, subject inspection, or broker-authored valuation was supplied. The closed-sale sample here is zero, so there is no local price estimate or numerical adjustment grid. The method explains what evidence a reviewer needs before producing that analysis. Begin with the San Anselmo guide for orientation and the selling process guide for transaction preparation.
Describe the existing property before looking for a price
Prepare a dated subject description that distinguishes documented facts from marketing language. Record the ownership interest, building configuration, measured areas and their sources, parking arrangement, outdoor spaces, access, and observed condition. Identify which areas are finished living space, accessory improvements, or unresolved classifications. A garage conversion and an approved addition should not become interchangeable just because both provide an attractive room during a showing.
The Town’s property lookup page points readers to MarinMap. Use that route to orient the investigation and locate the parcel. Then obtain the records needed to verify the relevant feature. An assessor entry, an aerial image, a listing description, and an approved plan answer different questions. Where their area figures differ, preserve the discrepancy rather than silently choosing the largest number for a pricing calculation.
Condition needs the same discipline. A new-looking finish does not establish the age or condition of concealed components. Ask what was changed, when, under what scope, and what completion evidence exists. Conversely, an older appearance alone does not prove that the systems require replacement. Keep the observations, repair reports, and construction documents attached to the property description so the eventual comparison does not depend on a vague renovated-versus-original label.
Separate parcel area from usable outdoor space
For a hillside subject, describe how the outdoor areas function: entry, level seating, gardening, storage, circulation, stairs, and the relationship between house and parking. Document those features with permissioned observations and an appropriate plan or survey where needed. Two equally sized parcels can offer different layouts without either being inferior for every buyer. The comparison should explain the difference that matters to the subject’s likely alternatives.
Do not convert an aerial outline into a certified usable-area calculation. The research may reveal a need for a surveyor, engineer, or other qualified reviewer before a particular terrace or proposed improvement can be evaluated. Keep existing utility separate from a buyer’s hoped-for project. A conceptual expansion is a different attribute from space that already exists with verified approvals and completion records.
Planning context also needs a date. San Anselmo’s Ordinance 2026-1201 replaces the earlier nonconforming-use provision with a new article addressing uses, structures, and lots. That change is a reason to obtain current advice about a specific property’s documented status. It does not establish that any particular home may be enlarged or rebuilt. A comparable’s supposed future potential should remain unsupported until the relevant history and current requirements have been reviewed.
Choose competing properties, then explain exceptions
Start the search with properties that could reasonably compete with the subject in configuration, setting, condition, ownership, and practical use. Keep the initial search boundaries and dates in the file. If the available evidence is thin, expand the search deliberately and state why. A nearby sale with a fundamentally different site can be less informative than a more distant property with a comparable layout and ownership burden.
Fannie Mae’s comparable-sales guidance discusses physical and legal similarity and explains that a competing market area may sometimes provide appropriate evidence. Those principles help frame questions for the professional performing the analysis. This article is not an appraisal or a statement that a lender will accept a particular selection. Its inclusion matrix below records the reason for considering a candidate before anyone assigns it a weight.
A decision matrix for the future verified sale file
Original research tool prepared October 25, 2026. Closed-sale sample: 0. No addresses below represent selected comparables, and no price adjustments have been calculated.
| Subject question | Candidate evidence | Selection decision to document |
|---|---|---|
| Hillside access and outdoor layout | Permissioned visit, measured information, relevant title and improvement records | Does it provide a competing pattern of entry, parking and outdoor use? |
| Creek relationship and ownership costs | Current parcel-specific mapping, disclosures, address-specific insurance evidence | Are material differences understood, or does uncertainty weaken the comparison? |
| Existing versus proposed space | Dated permits, approved plans and completion evidence | Compare existing verified utility; keep prospective work separately labeled. |
| Public open-space convenience | Current Town route information and verified practical connection | Describe access without claiming a price premium or private easement. |
| Transaction and timing | Verified closed-sale information, terms and relevant dates | Explain inclusion, uncertainty, concessions and supported market analysis. |
For every candidate retain its source, permission status, unresolved questions, inclusion or exclusion reason, and reviewer. Leave the price-conclusion field open until the evidence supports it.
Do not turn a public improvement into an automatic premium
The Town’s July 3, 2026 newsletter documents completion of the County’s Sorich Park trail upgrade at the end of June. That provides a dated public-access fact for a setting discussion. It supplies no sale evidence measuring how buyers priced the improvement. Nor does a public trail connection establish a private property’s right to cross neighboring land to reach it.
For a candidate described as convenient to open space, verify the practical public approach and explain the route from an appropriate lawful observation point. Avoid advertising an unverified shortcut. Then look for actual transaction evidence if someone proposes a premium. The same separation applies to flood-related public works: a project description, a parcel’s mapped conditions, and an insurer’s written offer are separate inputs. None alone produces a property-specific dollar adjustment.
Verify the sale and retain the terms
Marin County’s Assessor Services page provides routes to sales data and parcel records. The Recorder’s index cautions that an index guides users to underlying documents and should not be solely relied upon for decisions about them. A transfer reference is a research lead. It does not substitute for verification of the property, transaction circumstances, or any concessions relevant to the comparison.
Retain the source and permission for each published sale detail, and distinguish contract timing from closing timing where the information is available. Keep active listings and pending transactions labeled separately from completed sales. Asking prices can show available competition, but combining them into a closed-sale average changes the meaning of the result. If a field cannot be verified, mark it unknown and explain how that limits reliance on the candidate.
Support adjustments and reconcile the result
Check for double counting before interpreting a candidate’s differences. A smaller level yard, a sloping parcel, and a particular retaining arrangement may describe overlapping aspects of the same site rather than three independent pricing effects. Likewise, a condition allowance and a separate repair deduction may cover the same work. Ask the reviewer to show how each difference was isolated and which evidence supports treating it separately. If that explanation cannot be made, keep the difference descriptive until further analysis is available. A longer adjustment grid does not become more reliable simply because it contains more numbers.
Fannie Mae’s adjustment guidance calls for market evidence behind differences and the treatment of concessions. Use that as a prompt to request an explanation, not as a source of a standard San Anselmo adjustment. A repair estimate measures a proposed expense; its effect on price still needs support. An improvement’s cost likewise does not prove an equal increase in sale value.
The eventual reviewer should explain which verified sales carry the most weight, why the subject differs, and which uncertainties remain material. If the evidence cannot support a precise conclusion, show that limitation instead of averaging unsupported adjustments. Keep the effective date and the next refresh trigger visible. A new verified sale, a resolved permit issue, or a changed understanding of the site may justify revisiting the analysis.
The completed file belongs alongside the broader Marin County context, with the local subject description and comparison rules preserved. That gives the buyer or seller a traceable explanation of how evidence led to the conclusion. Until verified sales and professional analysis are available, this framework remains preparation for that work rather than a finished opinion of value.
