When determining property value, one of the most critical concepts in real estate appraisal is highest and best use (HBU). Professional standards require appraisers to develop an opinion of HBU when necessary for credible assignment results. HBU refers to how a property should be used to generate maximum value under specific constraints, not necessarily how it’s currently being used.
Jump to a Section
- Definition of Highest and Best Use
- Why Highest and Best Use in Appraisal Matters
- The Four Tests of Highest and Best Use in Appraisal
- Determining Highest and Best Use
- Special Considerations in HBU Analysis
- What’s New: Fannie Mae’s HBU Policy Under UAD 3.6
- Survey: What’s the Most Common Error Appraisers Make When Performing an HBU Analysis?
- Conclusion
Definition of Highest and Best Use
In professional appraisal practice, Highest and Best Use is defined as “the reasonably probable use of property that results in the highest value. The four criteria that the highest and best use must meet are legal permissibility, physical possibility, financial feasibility, and maximum productivity” (Appraisal Institute, The Dictionary of Real Estate Appraisal, 8th ed., 2026). This definition emphasizes that HBU must be reasonably probable, not merely possible or speculative.
For improved properties, appraisers analyze the property both as though vacant and as improved, considering what is legally permissible, physically possible, financially feasible, and maximally productive in the current market.
Why Highest and Best Use in Appraisal Matters
Highest and best use gives stakeholders insight into a property’s worth at its full potential. It guides market value determinations that reflect the property’s full potential and informs development and investment decisions based on feasibility and profitability. Additionally, HBU supports lending and underwriting decisions, especially for construction loans or redevelopment projects, guiding land use planning and zoning analysis in areas where land uses are changing.
The Four Tests of Highest and Best Use in Appraisal
Appraisers apply four tests to identify which use adds the most value to a property.
Legally Permissible
The first test evaluates what is legally permissible on the property. This includes examining zoning ordinances, building codes, land use regulations, deed restrictions, and environmental regulations. Private restrictions, such as easements and covenants, must also be considered, as they can significantly limit potential uses. Uses that are currently allowed, or most probably allowable (for example, through a reasonably probable rezoning or variance), move forward to the next test.
Physically Possible
The second test assesses the physical characteristics of the property to determine what is physically possible. Appraisers consider the lot size and shape, topography, access to utilities, ingress and egress, soil conditions, and environmental factors.
The physical analysis should also evaluate the surrounding infrastructure and its capacity to support various uses. The site’s physical attributes often eliminate many legally permissible uses from consideration.
Financially Feasible
The third test determines economic viability by analyzing whether potential uses would generate sufficient income or value to justify development or conversion costs. Appraisers must consider market demand for the proposed use, construction and development costs, potential income or sales prices, and expected return on investment.
This requires thorough market analysis examining supply and demand factors, absorption rates, and competitive positioning. Only uses that produce a positive return to the land, after considering risk and all costs to create and maintain the use, advance to the final test.
Maximally Productive
The fourth and culminating test identifies which legally permissible, physically possible, and financially feasible use produces the highest value or return. This analysis applies to all property types—residential, commercial, industrial, and special-purpose properties alike.
For example, if a property could legally and physically support either a retail center or an apartment building and both are financially feasible, then the appraiser must determine which use generates the highest residual land value or net return.
Determining Highest and Best Use
The highest and best use determination process requires comprehensive market analysis and distinct analyses of the property “as vacant” and “as improved.”
Market Analysis: The Foundation
A thorough market analysis forms the foundation of credible HBU determination. This analysis examines supply and demand factors for various potential uses, studies competitive properties and their performance, analyzes absorption rates and market trends, and considers economic and population factors, such as employment, household growth, and income, that affect property values. It also evaluates the regulatory environment and potential changes.
This market analysis informs all four tests but is particularly critical for financial feasibility and maximum productivity determinations.
HBU Analysis Framework
The process involves three interconnected analyses.
First, the Land as Though Vacant Analysis identifies potential uses that pass all four tests, determines which use would generate the highest land value, and establishes a baseline for comparing the value contribution of existing improvements. The first part of determining HBU involves researching legal constraints and analyzing physical characteristics, with financial feasibility determined through comparative market analysis and demand evaluation.
Second, the Property as Improved Analysis examines the property with its existing improvements to determine whether the current use represents the property’s HBU, if modifications to existing improvements would increase value, and if demolition and redevelopment would yield higher value than the current use. This analysis compares the property’s current value to its value under alternative scenarios, including renovation, conversion, expansion, or redevelopment.
Finally, the Comparative Analysis compares the results of both previous analyses. If the value of the land as vacant (less demolition costs) exceeds the value of the property as improved, this suggests demolition and redevelopment represent the highest and best use. Conversely, if the property as improved generates greater value than alternative uses of the vacant land, then maintaining or enhancing existing improvements represents the HBU. Appraisers should consider both short-term and long-term profitability in this analysis.
Special Considerations in HBU Analysis
Several special considerations often arise in HBU analysis that appraisers must address.
Interim Uses
When market conditions don’t currently support the ultimate highest and best use of a property but may do so in the future, appraisers must consider interim uses that maximize value until conditions improve.
For example, a downtown parcel might have an ultimate HBU as a high-rise office building, but current market conditions don’t support such development. An interim use, such as a surface parking lot, may be the most productive use of the site in the meantime. In that case, the HBU conclusion would typically be to hold the site for future office development, with surface parking as the interim use.
Interim uses often help defray holding costs, such as real estate taxes, while the owner waits for the ultimate use to become feasible. The principle of consistent use also applies: the land and the improvements must be valued on the basis of the same use, so improvements that don’t support the interim use shouldn’t be credited with value.
Excess and Surplus Land
Appraisers must also distinguish between excess and surplus land in their highest and best use analysis.
Excess land is land that is not needed to serve or support the existing use and has the potential to be sold separately, such as a subdividable parcel. Its HBU may or may not be the same as that of the improved parcel, and it is valued separately.
Surplus land, however, is not currently needed to support the existing use but cannot be separated from the property and sold off for another use because of zoning, physical constraints, or other limitations. It does not have an independent HBU and may or may not contribute value to the improved property. Any contribution is valued as part of the primary site. This distinction is crucial for accurate valuation, particularly for properties with large land areas relative to their improvements.
Special-Use Properties
Highest and best use analysis for special-use properties such as religious facilities, schools, or highly specialized industrial facilities presents unique challenges. For these properties, appraisers must consider the concept of “value in use” versus “value in exchange,” limited marketability and specialized buyer pools, potential for adaptive reuse, and the contribution of specialized improvements to value.
The HBU of special-use properties often depends on the specific needs of a limited market segment, requiring careful market analysis and consideration of alternative uses.
Changing Market Conditions
Finally, appraisers must recognize that highest and best use is dynamic and can change with market conditions, regulations, and technological advancements. They must consider current market trends and their trajectory, potential regulatory changes affecting permissible uses, emerging uses that might not have historical precedent, and alternative scenarios based on different market projections.
This forward-looking aspect of HBU analysis is particularly important in areas where land uses are changing or in rapidly changing markets.
What’s New: Fannie Mae’s HBU Policy Under UAD 3.6
For residential appraisers, highest and best use is more than a valuation concept. It is also a GSE eligibility requirement, and in September 2026, Fannie Mae changed it. In Selling Guide Announcement SEL-2026-08, Fannie Mae updated its HBU policy for appraisals completed on the redesigned Uniform Residential Appraisal Report (URAR) under Uniform Appraisal Dataset (UAD) 3.6.
What Changed
Residential use, not present use. Under the prior guidance, the present use of the property generally had to be its highest and best use. Now the property’s HBU, as improved or as proposed, must be a residential use. It no longer has to be the present use.
Primarily residential 1-4 unit properties. The property must be primarily a one- to four-unit residential property, and any non-residential use must be subordinate to the residential use. This replaces the earlier “residential in nature” standard. Fannie Mae’s UAD 3.6 Policy Supplement defines present use, residential use, and subordinate use for this purpose.
A path for properties that fail an HBU test. The update sets eligibility criteria and reporting requirements for one- to four-unit residential properties whose present use fails one or more of the four HBU tests.
When It Applies
The policy applies to appraisals completed on UAD 3.6. It does not apply to appraisals completed on the legacy forms. As of November 2, 2026, UAD 3.6 is required for new submissions to the Uniform Collateral Data Portal (UCDP), so most Fannie Mae appraisals now fall under the new policy.
Some lenders have more time. Under a temporary exception announced September 30, 2026, approved sellers that requested it from Fannie Mae or Freddie Mac can keep submitting UAD 2.6 appraisals on the legacy forms through May 19, 2027. UAD 3.6 becomes mandatory for everyone on May 20, 2027. Until then, you may get assignments in both formats. The new HBU policy applies only to UAD 3.6 reports, so confirm your client’s UAD requirements before you accept an assignment.
Freddie Mac has not made the same HBU change. As of its September 2026 guide update, Freddie Mac still requires the present use to be the highest and best use. Because the two GSEs now differ, confirm with your client which guidelines apply when the present use is not the HBU.
What It Means in Practice
Consider an older single-family home on a lot that was recently rezoned for townhomes. The existing house may no longer be the maximally productive use of the site. Under the old approach, that conflict could raise an eligibility problem. Under UAD 3.6, the HBU is still residential, so the property may remain eligible if it meets Fannie Mae’s criteria and the appraisal reports the analysis as required.
The redesigned URAR also puts more weight on narrative, evidence-based support for the HBU conclusion than the legacy forms did. Be ready to explain why the market supports a residential use, whether any non-residential use (such as a home-based business or agricultural outbuildings) is subordinate, and, when the present use fails a test, which test it fails and why. For exact definitions and reporting requirements, read the UAD 3.6 Policy Supplement.
Survey: What’s the Most Common Error Appraisers Make When Performing an HBU Analysis?
A recent McKissock survey revealed a clear concern among appraisers: 50% of respondents identified treating highest and best use as a formality rather than a critical valuation step as the most common error in HBU analysis. Other frequently cited mistakes included overreliance on a property’s current use (11%), misunderstanding legal or zoning limitations (11%), and insufficient market support for the selected use (8%).
A sound HBU analysis requires careful consideration of legal, physical, financial, and market factors, along with clear documentation of the appraiser’s reasoning. When performed thoroughly, the analysis helps ensure that the value opinion reflects a property’s most productive use in the current market rather than assumptions based solely on its existing use.
Conclusion
Determining the highest and best use requires multiple valuation methods and professional judgment. For improved properties, appraisers evaluate the site as though vacant and the property as improved, systematically applying the four tests: legal permissibility, physical possibility, financial feasibility, and maximum productivity.
The HBU analysis forms the foundation for credible valuation opinions through rigorous market analysis and a thorough understanding of physical and legal characteristics. It represents one of the most analytical aspects of the appraisal process and directly influences the final value conclusion.
As market conditions and regulations evolve, so does a property’s highest and best use. Appraisers who stay current with industry trends and changing regulations maintain a competitive advantage—that’s where McKissock Learning can be your trusted ally.
McKissock offers appraisal continuing education and license renewal courses in every state, including Residential Market Analysis and Highest and Best Use.
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