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On October 26, 2026, four major brokerage organizations announced Open Real Estate (ORE), a proposed national listing data-sharing platform that could change how property information moves among brokerages, MLSs, portals and appraisers.
For Baltimore appraisers, the opportunity is real. More accessible listing information could make it easier to find transactions that now stay inside private brokerage networks. But the announcement leaves one question open: will more listing data actually mean better comparable-sale data?
After 37 years appraising in Baltimore City and the surrounding counties, I know the difference matters. A Canton rowhouse may carry ground rent. A finished lower level in Federal Hill may not count as above-grade living area. Two homes a block apart can face different buyer demand. Those details can change a credible opinion of market value.
Last updated October 28, 2026. ORE is a proposal, and I will update this page if final platform rules, access policies or MLS integrations are announced.
What is Open Real Estate (ORE)?
Open Real Estate is a proposed national, industry-led residential listing data-sharing system. Agents enter a listing once, using minimum standard fields. Listings marketed publicly (ORE calls this “market view”) are delivered to MLSs, home search sites, portals, data services and appraisers at the same time.
Open Real Estate (ORE) was announced by four founding members: AGNT (the parent of eXp Realty), Keller Williams Realty, HomeServices of America (which includes Berkshire Hathaway HomeServices) and Real REMAX Group. Brown Harris Stevens, Lamacchia Realty, Samson Properties and Windermere Real Estate are listed as initial participating members.
The founders say ORE is not a consumer portal and does not replace your local MLS. Their open letter describes it as a response to homes being marketed privately, outside public listing systems, in ways that limit competition and reduce transparency. Their stated principles are to expand buyer opportunity, empower informed seller decisions, protect data integrity and promote fair competition.
Principle three, data integrity, is the one that matters to people who sign appraisal reports. ORE says all members and users should have full visibility into homes for sale and the information when they sell.
What is the one-business-day rule, and will it end private listings?
ORE's rules say members must enter every listing within one business day of signing the listing agreement, and any listing that goes public anywhere must also be in ORE. But sellers can choose a members-only participant view, so ORE may narrow private inventory without eliminating it.
Appraisers know the problem this aims at. Picture a rehabbed rowhouse in Patterson Park that trades quietly inside one brokerage's network, or a waterfront sale near the Harbor that never shows the exposure a lender expects. (Those are illustrative examples, not specific assignments.) The appraiser is then asked to explain, support or defend a comparable the open market never got a fair look at.
ORE draws a line between two kinds of listings. In participant view, only agents at participating brokerages can see the listing, and it is not publicly marketed. In market view, the listing is public and goes to MLSs, portals, appraisers and data services at the same time it reaches ORE members. Appraisers are named as recipients of the public listings.
An off-market sale is not automatically an unusable comparable. Choosing comparables and verifying details such as arm's-length status and concessions is still the appraiser's job. What better data should do is make discovery and verification easier. It does not replace the appraiser's judgment about whether a sale is good evidence.
One caution: ORE is a proposal. The site says the founders will spend the next six months engaging participants and finalizing governance and technology plans with MLS organizations and other stakeholders. Brokerages and MLSs are being asked to sign a non-binding letter of support, not to commit to the rules. ORE's FAQ says vendor selection is expected to finish during Q1 2027, after which the system would begin rolling out to participant companies, and HousingWire reports the founding members are not charging brokerages to join.
Where does Bright MLS fit in Maryland?
ORE says it complements MLSs and does not replace them, so Bright MLS should remain a critical regional source for Baltimore listing and transaction data, one that still requires verification. ORE is better understood as a possible second front door, and a possible safeguard against fragmented public marketing.
Maryland appraisers are fortunate. Bright MLS is one of the largest consolidated regional MLSs in the country, and it already sets a high bar for data pooling. In many parts of the U.S., an appraiser has to juggle several small, non-reciprocal boards just to cover a 15-mile radius.
The ORE letter says local MLSs will keep establishing and enforcing local listing rules, and its FAQ says it will work in partnership with existing MLS systems. No ORE integration with Bright MLS has been announced, so I am not assuming one. As I read it, ORE's potential value to us is capturing publicly marketed listings that might otherwise never reach the MLS. For sales that already do, Bright MLS remains where the full detail lives.
Will Open Real Estate solve the hidden comparable sales problem?
Not entirely. ORE could make more listings discoverable, but a listing feed is not the same as a verified comparable-sale record. Access to listing information does not automatically supply the transaction details an appraiser needs.
Take a Baltimore rowhouse that sells through a brokerage's private network. Before I can use that sale, I may need to establish:
- Whether the transaction was arm's length.
- How the property was exposed to potential buyers.
- Whether seller concessions affected the sale price.
- Whether finished basement space was included in the reported square footage.
- Whether ground rent, easements or other characteristics affected the price.
- Whether the sale reflects the same competitive market as the property I am appraising.
A more complete database might help me find that sale. I still need reliable information to decide whether it is appropriate comparable-sale evidence. The real opportunity is not finding more sales. It is finding more sales that can be independently verified and properly analyzed. That is the difference between a larger real estate database and a stronger appraisal.
Why do "minimum standard fields" worry me in Baltimore?
ORE is built around entering a listing once with minimum standard fields. In a market like Baltimore, a minimal listing can leave out the details that move value: ground rent, below-grade finished space, block-level location and seller concessions.
- Ground rent. Is the property fee simple, or subject to a Maryland ground rent? A generic national form is not built for that, and it affects marketability and title. I explain the mechanics in How Baltimore Ground Rent Affects Appraisals.
- Basements and rowhouse layouts. Under applicable ANSI measurement rules, a level that is partly below grade is generally reported separately from above-grade finished area, even when it is beautifully finished. If a simplified form lets an agent report one blended square footage number, gross living area gets distorted fast.
- Micro-markets. In Baltimore City, value can shift dramatically from one block to the next. A feed that rolls neighborhoods together by ZIP code tells you very little.
- Concessions. Seller credits, rate buydowns and transfer tax splits are common in today's market. If concessions are not reported clearly, I still have to call the listing agent to verify them.
- Historic status. A listing field rarely says whether a home sits in a CHAP district or carries a tax credit. That can change what buyers pay, as I show in the CHAP halo effect article.
If a national feed leaves out what Bright MLS captures today, I will keep pulling the Bright sheet to get the full story. I have been doing that for decades, and it is why verification is part of every appraisal I sign.
How does ORE connect to UAD 3.6?
Fannie Mae and Freddie Mac's new UAD 3.6 appraisal report reaches its general mandate on November 2, 2026, with limited temporary exceptions for approved sellers. ORE could eventually help connect listing data to mortgage data, but it is a proposal and its technology plans are still being finalized.
The timing is a coincidence, but a useful one. UAD 3.6 moves the appraisal from a long form with narrative addenda to a structured, machine-readable report built on the MISMO 3.6 data standard, with more detailed property condition and quality reporting. Appraisal software already imports comparable data from the MLS, and a cleaner, more complete listing feed could reduce re-keying and flag discrepancies before an underwriter does.
On the deadline itself: the GSEs are letting approved sellers who request an exception keep submitting UAD 2.6 appraisals through May 19, 2027, and UAD 3.6 becomes mandatory for all new submissions on May 20, 2027. Whether that applies to your loan depends on your lender, so ask.
A structured report is only as good as the structured data behind it, which is exactly why the questions about minimum fields matter. Your lender's appraisal for a purchase or refinance is a separate matter from any of this; see what an independent appraiser does for how those engagements differ.
What does this mean for Baltimore homeowners, estates and lenders?
Nothing changes for you today. Your appraisal will still depend on local comparable selection, property-specific adjustments and local market knowledge, none of which a national feed can supply on its own.
- Local comparable selection. Knowing which sale is truly comparable and which one is not.
- Property-specific adjustments. Ground rent, condition, layout and historic character.
- Local market knowledge. The economic boundary of Patterson Park, the effect of a historic tax credit in Mount Vernon, and the legal reality of a Maryland ground rent lease.
This matters in the work I do every day: estate and probate valuations, divorce, SDAT tax appeals, CHAP historic tax credit properties, FHA and multifamily. I also bring 20 years of reverse mortgage (HECM) experience as an FHA appraiser. In every one of those assignments, the number holds up only if the data underneath it is complete and verified.
Is Open Real Estate good for Baltimore appraisers?
In broad strokes, yes. Anything that keeps listing data from splintering into private corporate silos protects an appraiser's ability to deliver credible, market-supported opinions of value. But a national pipeline cannot replace local competence.
I have never seen technology replace local competence. A national pipeline can move data faster. It cannot walk the block, read the basement or understand the ground rent. If ORE launches, I expect to welcome the extra visibility, and to keep telling lenders and underwriters that accuracy still comes from local context.
Experience builds value. AI builds leverage.
Frequently asked questions
What is Open Real Estate (ORE)?
A proposed national, industry-led residential listing data-sharing initiative. Agents enter listings once using standardized fields, and public listings are delivered to MLSs, portals, appraisers and data services.
Who founded Open Real Estate?
AGNT (eXp Realty), Keller Williams Realty, HomeServices of America (Berkshire Hathaway HomeServices) and Real REMAX Group. Brown Harris Stevens, Lamacchia Realty, Samson Properties and Windermere Real Estate are listed as initial participating members.
Does ORE replace or connect to Bright MLS?
ORE does not replace MLSs. It says it complements them, will work in partnership with existing MLS systems, and does not set or change MLS rules. No integration with Bright MLS has been announced.
What is the one-business-day rule?
ORE's rules would require members to enter each listing within one business day of signing the listing agreement, and any listing that becomes public elsewhere must also be in ORE. Sellers can still choose a members-only participant view that is not publicly marketed.
Will Open Real Estate end private listings?
Not by itself. ORE allows a members-only participant view for listings that are not publicly marketed. Appraisers are named as recipients of public market-view listings.
Is ORE live yet?
No. The ORE site describes it as a proposed platform. For the next six months the founders plan to engage participants and finalize governance and technology plans with MLS organizations and other stakeholders. Joining so far means signing a non-binding letter of support.
Can appraisers use off-market sales as comparable sales?
Yes. An off-market transaction is not automatically excluded. Whether it is useful depends on whether the appraiser can verify the transaction, assess its terms and conditions, and determine that it is credible market evidence.
Can private listings affect real estate appraisals?
They can make relevant transactions harder to discover and verify, and limited market exposure may affect how a sale is interpreted. The effect depends on the specific property, transaction and market.
Will Open Real Estate give appraisers access to every home sale?
No such access is guaranteed. ORE's published rules distinguish between members-only participant listings and publicly marketed listings, appraisers are named as recipients of the public ones, and the platform is still being designed.
Will ORE change how Baltimore appraisals are done?
Not immediately. The value of any appraisal still comes from local analysis, verification and professional judgment, including details like ground rent, below-grade space and block-level location.
When is UAD 3.6 mandatory?
Fannie Mae and Freddie Mac's UAD 3.6 report reaches its general mandate on November 2, 2026. Approved sellers that request a temporary exception may keep submitting UAD 2.6 appraisals through May 19, 2027, and UAD 3.6 is mandatory for all new submissions from May 20, 2027. Ask your lender how it applies to your loan.
Who appraises homes in Baltimore City, Baltimore County, Carroll County and Harford County?
I do. Ed Drost is a Maryland State Certified Residential Appraiser, license #30004874, based in Parkton and appraising in the region since 1989. Call 443-904-5229 for a free quote.
More articles
What Is an Independent Real Estate Appraiser? A Baltimore-Area Guide
What independent means, how it differs from a lender's appraisal, what it costs in Baltimore, and when to hire one.
How Does Baltimore Ground Rent Impact Home Appraisals and Market Value?
How ground rent works, how the redemption price is figured at 6%, and how appraisers account for it in Baltimore.
Who Legally Owns the Appraisal Report: The Homebuyer or the Mortgage Lender?
Who owns the appraisal you paid for? The lender is the client, and you have a legal right to a copy.
Related pages
Sources: Open Real Estate, Housing markets must remain open to all (open letter, platform rules and FAQ) · Open Real Estate FAQ · HousingWire, Open Real Estate could reshape listing access if most brokerages join · HousingWire, GSEs' temporary UAD 3.6 exception · The CE Shop, UAD 3.6 is coming November 2. Open Real Estate is a proposed platform; details may change before launch.