What Drives the Cost of a Hangar Appraisal

Abstract

1. Introduction

Owners ask what a hangar appraisal costs and are frustrated when the answer is a question. The frustration is fair. The question is not evasion.

Two hangars of identical size at the same airport can require very different amounts of work, and the difference is rarely visible from the ramp. It sits in the ground lease, in what the report has to survive, in whether the airport will release its data, and in conditions of the building that a photograph will not show. None of those is negotiable by wishing.

The reason this is more than a billing complaint is that the profession's own standards place the scope decision with the appraiser and then test it against an external benchmark. An appraiser who quotes a fee before the scope is known has either made assumptions that may be wrong or has quietly decided what the assignment will not include. The first produces a change order. The second produces a report that does not support the use it was commissioned for, which is the more expensive outcome and the harder one to detect.

This paper sets out the determinants. Section 2 establishes where the scope decision sits and what it is measured against. Sections 3 through 6 take the four forces that move it. Section 7 addresses approach selection and what is known about the spread between independent appraisals of the same asset. Section 8 reports what is and is not known about appraisal fees. Section 9 sets out what a client can do about it. The paper quotes no fees, for a reason Section 8 explains.

2. Scope Is the Variable, Not Size

2.1 Where the decision sits

The governing rule is short. For each assignment an appraiser must "identify the problem to be solved," "determine and perform the scope of work necessary to develop credible assignment results," and "disclose the scope of work in the report," and "must be prepared to demonstrate that the scope of work is sufficient to produce credible assignment results" (Appraisal Standards Board 2024, Scope of Work Rule, at 15).

Scope includes "the extent to which the property is identified," "the extent to which tangible property is inspected," "the type and extent of data researched," and "the type and extent of analyses applied to arrive at opinions or conclusions." Appraisers have "broad flexibility and significant responsibility" in determining it, and "[c]redible assignment results require support by relevant evidence and logic," with credibility "always measured in the context of the intended use."

Problem identification requires the six assignment elements: client and other intended users, intended use, type and definition of value, effective date, the subject and its relevant characteristics, and assignment conditions. The rule then places a boundary on the client's role that is easy to miss and central to this paper: "Communication with the client is required to establish most of the information necessary for problem identification. However, the identification of relevant characteristics is a judgment made by the appraiser that requires competency in that type of assignment."

A hangar assignment tests that sentence immediately. Whether a ground lease reversion clause is a relevant characteristic, whether the door opening is a relevant characteristic, whether a firefighting foam history is a relevant characteristic, are judgments the appraiser must make and must be competent to make. A client who does not raise them has not thereby removed them.

2.2 The acceptability test is external

Scope is not acceptable because the client agreed to it. The standard states two independent benchmarks: scope is acceptable when it meets or exceeds "the expectations of parties who are regularly intended users for similar assignments" and "what an appraiser's peers' actions would be in performing the same or a similar assignment," where peers means "other appraisers who have expertise and competency in a similar type of assignment" (Appraisal Standards Board 2024, at 3, 16).

The second benchmark is the one that prices aviation work. Peers are not appraisers generally; they are appraisers competent in this assignment type. What a competent industrial appraiser would do with a warehouse is not the measure. The rule adds the corollary directly: "An appraiser must be prepared to support the decision to exclude any investigation, information, method, or technique that would appear relevant to the client, another intended user, or the appraiser's peers."

Determining scope is also continuous rather than a one-time act. "Information or conditions discovered during the course of an assignment might cause the appraiser to reconsider the scope of work." An amendment discovered in week two is not a pricing failure; it is the rule operating as written.

2.3 Where the appraiser cannot yield

Two provisions convert scope from a commercial negotiation into a professional obligation, and they are the reason a cheaper proposal is sometimes not a cheaper version of the same assignment.

First: "An appraiser must not allow assignment conditions to limit the scope of work to such a degree that the assignment results are not credible in the context of the intended use." Where information is unavailable because of conditions that limit research, the appraiser "must withdraw from the assignment" unless the conditions can be modified to include gathering the information, or an extraordinary assumption can be used and credible results still developed.

Second: "An appraiser must not allow the intended use of an assignment or a client's objectives to cause the assignment results to be biased," a prohibition repeated in the problem identification rule itself (Appraisal Standards Board 2024, Standards Rule 1-2(b)).

The extraordinary assumption is the pressure valve, and it is bounded. It may be used only if it "is required to properly develop credible opinions and conclusions," the appraiser "has a reasonable basis" for it, and its use "results in a credible analysis" (Standards Rule 1-2(f)). It is defined as an assignment-specific assumption, "as of the effective date," regarding uncertain information used in an analysis "which, if found to be false, could alter the appraiser's opinions or conclusions." An assumption is therefore a disclosed transfer of risk to the reader, not a way to make a problem go away, and each one narrows what the report can be relied on for.

There is a third provision, and it forecloses the workaround a client under fee pressure is most likely to reach for. The standards recognise that a law or regulation can displace part of them, but they are specific about what counts. A jurisdictional exception arises where "any applicable law or regulation precludes compliance with any part of USPAP," and the rule states in terms that "[i]nstructions from a client or attorney do not establish a jurisdictional exception." A client cannot create an exemption by asking for one, and neither can their counsel. What a real jurisdictional exception looks like is visible in federal acquisition work, where the Uniform Appraisal Standards for Federal Land Acquisitions displaces parts of the standards by operation of federal law rather than by instruction.

The Appraisal Foundation addresses these questions at length in advisory material, now published separately from the standards themselves: Advisory Opinion 19 on unacceptable assignment conditions, 28 on the scope of work decision, performance and disclosure, and 29 on an acceptable scope of work. A 2026 addition, Advisory Opinion 41 on the use of technology in an appraisal or appraisal review assignment, addresses a question this paper does not take up but which will bear on scope pricing before long.

3. The Ground Lease Moves the Number First

Most hangars sit on leased public land. Before valuation work begins the lease has to be read: remaining term, renewal mechanics and who controls them, rent reset language, reversion of improvements, assignment and leasehold mortgage provisions, and any sponsor option to purchase or recapture.

A lease with a long remaining term, a tenant-controlled renewal at a determinable rent and a clear surrender clause is a short read. A lease amended four times across thirty years, with a side letter and an unrecorded consent to assignment, is a different assignment. The difference is not a matter of page count; it is that the second document may change the interest being appraised.

The standard makes the lease a mandatory identification rather than a discretionary one. The appraiser must identify "the real property interest to be valued" and "any known easements, restrictions, encumbrances, leases, reservations, covenants, contracts, declarations, special assessments, ordinances, or other items of a similar nature," together with "any personal property, trade fixtures, or intangible assets that are not real property but are included in the appraisal" (Standards Rule 1-2(e)). Hangar assignments routinely carry trade fixtures and non-realty components, so that last clause is not boilerplate.

Why this drives value rather than merely paperwork is developed at length elsewhere: a tenant-built hangar on leased land is a finite claim with no terminal value, and its worth follows from the remaining term rather than from what the building cost (Carter 2026a). An appraiser who quotes before reading the lease is quoting on the assumption that the term is long and the clause is standard. Where it is not, either the fee changes or the analysis thins.

4. Intended Use Sets the Standard the Work Must Meet

Intended use is the element clients most often leave vague, and the one that changes the documentation burden furthest. The analysis underneath two reports may be similar; the support required for every adjustment, and the anticipation of a reviewer's objections, are not. Five regimes are set out below because each imports a different instrument.

Source: Instruments as cited.

4.1 Bank lending

The federal banking agencies raised the appraisal threshold for commercial real estate transactions from $250,000 to $500,000 in 2018, providing that transactions exempted by the revised threshold still require "an evaluation of the real property collateral that is consistent with safe and sound banking practices" (Real Estate Appraisals, 83 Fed. Reg. 15019, 15019 (Apr. 9, 2018)). Above the threshold the appraisal enters a review process built to catch unsupported adjustments, and the documentation has to anticipate it (Interagency Appraisal and Evaluation Guidelines 2010). Where the collateral is a leasehold hangar the review will reach the lease term against the loan term, which is a separate underwriting question (Carter 2026b).

4.2 FAA land release and disposal

The agency's requirement is specific and is frequently discovered late. A release authorizing the sale or transfer of airport land "shall not be granted unless the fair market value has been supported by at least one independent appraisal report acceptable to the FAA," and appraisals "shall be made by an independent and qualified real estate appraiser" (Federal Aviation Administration 2026, para. 22.21(a)). Value is determined on the present appraised value for highest and best use of the land and any federal improvements initially conveyed with it, and a disposal below fair market value is inconsistent with the statute except as provided by the community use carve-out at 49 U.S.C. 47107(v).

The requirement is waivable on two grounds: where the approximate fair market or salvage value is less than $25,000, or where public advertising and sale to the highest responsible bidder would be in the public interest. A scoping conversation that establishes which side of $25,000 the parcel falls on is worth having before an engagement letter, not after.

The intended user requirement comes from a separate instrument. Compliance Guidance Letter 2018-3 states that "[t]he intended user of this appraisal report is the sponsor and the FAA," provides that appraisers "should" be listed on the national registry, expressly permitting a Certified Residential Appraiser where the property is a residence, and expresses a preference for "an appraiser having extensive airport valuation experience" (Federal Aviation Administration 2018). Naming a second intended user is not a formality; it changes what the report must contain, because the acceptability test in Section 2.2 is measured against the expectations of intended users.

One feature of that letter deserves notice in a paper about standards. It provides that the agency "will only accept an Appraisal Report that meets the essential steps outlined in USPAP, 2016-2017 Edition." That edition has been superseded three times, by the 2018-2019, 2020-2021 and 2024 editions. The letter also supports Order 5190.6B, which Order 5190.6C cancelled on 20 February 2026. So an appraiser preparing a release appraisal is complying with a current edition of the standards under guidance that points at an old one, issued in support of an order that no longer exists.

4.3 Litigation

Work that will be deposed has to be built so that every number traces to a source and survives questioning by someone paid to break it. The rule changed in a way that matters. As amended effective 1 December 2023, Federal Rule of Evidence 702 requires that "the proponent demonstrates to the court that it is more likely than not" that the four conditions are met, and recasts the fourth so that "the expert's opinion reflects a reliable application of the principles and methods to the facts of the case." The amendment makes the burden explicit and directs the court to police whether an opinion claims more than its method supports. Kumho Tire Co. v. Carmichael, 526 U.S. 137 (1999), is the branch of Daubert that reaches technical and specialized expertise, which is where appraisal sits.

Courts have not been uniformly hostile to appraisal testimony. In United States v. 14.38 Acres of Land, 80 F.3d 1074 (5th Cir. 1996), the court reversed the exclusion of a landowner's appraiser, holding that the trial court had applied too stringent a reliability standard and that attacks on the selection of comparables went to weight rather than admissibility. That decision predates both Kumho Tire and the 2023 amendment, and a paper claiming the documentation burden has risen should say so rather than lean on it.

4.4 Tax

A charitable contribution of property valued above $5,000 requires a qualified appraisal, and above $500,000 the appraisal must be attached to the return (IRC 170(f)(11)). The regulation prescribes the report's contents in detail, including the valuation method employed and "the specific basis for the valuation," and requires the appraiser to have verifiable education and experience in valuing the type of property at issue (26 C.F.R. 1.170A-17).

The exposure runs to the appraiser personally. Where an appraisal results in a substantial or gross valuation misstatement, the penalty is "the lesser of" the greater of ten percent of the underpayment or $1,000, or "125 percent of the gross income received by the person ... from the preparation of the appraisal" (IRC 6695A(b)). No penalty applies if the appraiser establishes that the value "was more likely than not the proper value." An engagement whose fee can become the measure of a penalty is scoped differently from one whose fee cannot, and the same "more likely than not" formulation that the 2023 evidence amendment imported now appears on both sides of the appraiser's risk.

5. Data Access Is the Sponsor's Decision

Hangar work depends on rent rolls, lease abstracts, rate schedules, minimum standards, waiting lists and transactions at comparable fields. Some sponsors publish all of it. Some release it on request. Some require a public records request and take weeks. Some hold rates in board minutes to be read one meeting at a time.

That does not change what the assignment requires, but it changes the hours, and where data cannot be obtained at all it can change the analysis. The standard is explicit about the sequence: if relevant information is unavailable because of conditions that limit research opportunities, the appraiser modifies the conditions to gather it, uses a supported extraordinary assumption, or withdraws.

The practical point for a client is that part of the honest answer to what an appraisal costs depends on how cooperative the airport is, which the client usually knows better than the appraiser does. A sponsor that publishes its rate schedule and minimum standards has already reduced the scope of every appraisal on its field.

6. Property Characteristics That Expand Scope

6.1 Fit, not floor area

Door width and height, clear span and clear height govern which aircraft a building can accept, and width is usually the binding constraint on wingspan. A hangar that cannot take the aircraft its market wants is worth less than its floor area suggests, and demonstrating that takes work that a square foot figure does not (Carter 2026c).

The fire code is currently moving underneath this question. The 2026 edition of NFPA 409 changed the aircraft access door height in the group definitions "for Group I, Group II, and Group III hangars from 8.5 m (28 ft) to 10.7 m (35 ft), which accounts for current aircraft design and hangar usage" (National Fire Protection Association 2026). A classification threshold is not a statement about which aircraft fit, and it should never be used as one, but it does determine the fire protection a building must carry, and a building near the boundary is a different cost and a different analysis on either side of it.

6.2 Environmental exposure, and a scope change imposed by law

Where firefighting foam was used or stored, the contamination question has to be handled explicitly, either analyzed with support from environmental professionals or carried as a disclosed extraordinary assumption.

The profession's own guidance places that decision inside the Scope of Work Rule rather than outside it. Appraisal Institute Guide Note 6 states that "[t]he SCOPE OF WORK RULE requires that, in any assignment, the appraiser establish the appropriate scope of work necessary to complete that assignment. Part of the scope of work decision includes how, and to what extent, the appraisal problem will address known or suspected hazardous materials that may impact the property." It then sets out the machinery: extraordinary assumptions are used "when relying on the work of others, such as environmental engineers or other technical specialists," hypothetical conditions when valuing a property known to be contaminated as though it were not, and an extraordinary assumption may be appropriate "in the event there is suspected but not confirmed contamination," in which case "[a]n environmental assessment by a qualified environmental professional would be required for such conclusions or determinations." On competency it is blunt: "Most appraisers do not have the knowledge or experience required to detect the presence of hazardous substances or to measure the quantities of such material."

Scope being set by something other than the client's instruction is illustrated by what happened on 8 July 2024. The Environmental Protection Agency designated perfluorooctanoic acid and perfluorooctanesulfonic acid as hazardous substances under the federal Superfund statute, effective that date (89 Fed. Reg. 39124 (May 8, 2024)). The ASTM Phase I environmental site assessment standard defines its required scope by reference to that statute, so before the designation PFAS was a non-scope consideration, permitted but not required and addressed only if the user asked for it. After the designation the same compounds sit inside the required scope, and are to "be evaluated as part of 'all appropriate inquiries' for Phase I ESA reports to qualify for CERCLA liability defenses" (Williams and Frost 2024).

The standard provides for this itself, which is worth quoting because it is the mechanism rather than a commentator's reading of it. ASTM E1527-21, Appendix X6.10, provides that "[i]f and when such emerging contaminants are defined to be a hazardous substance under CERCLA, as interpreted by EPA regulations and the courts, such substances shall be evaluated within the scope of this practice." Before that trigger fired, the same appendix said it was "permissible to include analysis and/or discussion of these substances in the same manner as any other Non-Scope Consideration." The standard was drafted with a conditional clause in it, and the agency pulled the trigger.

One clarification belongs with this, because the point is often overstated. What enters the required scope of a Phase I is records review and identification of conditions indicative of a release. A Phase I is non-intrusive and does not include laboratory sampling, so the designation expands the inquiry rather than converting it into a testing programme. The cost consequence for the appraisal is nonetheless real, because the appraiser now has either a finding to reflect or a gap to disclose.

Not a word of the ASTM standard changed. The scope changed because the statute's list changed. For a hangar with foam history, an environmental professional's work expanded on a date certain, and that flows through to what the appraiser must assume, disclose, or refuse to assume. The valuation consequences are developed separately (Carter 2026d).

6.3 Aeronautical and non-aeronautical use

Sponsors are constrained in what they may charge for each use, and the rent structure follows the classification rather than the building. Federal policy recognizes storage of active aircraft, final assembly, non-commercial construction of amateur-built or kit-built aircraft, and maintenance, repair or refurbishment as aeronautical uses, permits incidental non-aeronautical storage where it does not interfere with the aeronautical use, and requires sponsors to charge "non-aeronautical fair market rental fees for the non-aeronautical use of airport property" (Policy on the Non-Aeronautical Use of Airport Hangars, 81 Fed. Reg. 38906 (June 15, 2016), effective July 1, 2017).

This is a structural difference from ordinary industrial valuation, not a detail. The same physical box commands a regulated, deliberately below-market rent in one use and fair market rent in another, and the sponsor has no discretion to charge fair market rent for aeronautical use. A highest and best use analysis cannot therefore be conducted on physical and economic grounds alone, and establishing which use governs is scope, not background reading.

6.4 Other conditions that reliably expand scope

Specialized improvements such as paint booths, maintenance bays, wash racks, fuel farms and heavy power service are not generic warehouse features and do not carry generic warehouse cost or depreciation treatment. Multiple interests can exist in one structure, with a sponsor's leased fee, a tenant's leasehold and a subleasehold each a distinct interest requiring its own opinion where it falls within the assignment. Each of these is a relevant characteristic under Standards Rule 1-2(e), which means the appraiser identifies it whether or not the client raised it.

7. Approach Selection and the Spread Between Appraisals

7.1 Three approaches is not the default

Cost, sales comparison and income are not automatically all required. Which are applicable, and which are merely available, is a judgment made after the facts are known, and the reporting standard requires the appraiser to state "the reasons for excluding the sales comparison, cost, or income approach(es) if any have not been developed" (Appraisal Standards Board 2024, Standards Rule 2-2(a)(x)(2)).

On leasehold hangars the income approach usually carries the analysis and the cost approach can mislead, because a building can cost far more to construct than the remaining lease term will support (Carter 2026a). Where sales of comparable hangars at comparable fields genuinely exist, sales comparison earns its place. Where they do not, forcing the approach adds pages and subtracts credibility. Excluding an approach is not a shortcut; under the rule above it is a disclosure that must be reasoned.

7.2 What the variance literature has measured

The question underneath all of this is how much two competent appraisers can differ on the same property. A body of empirical work has measured it, in several countries and across four decades, and the answer is wider than most clients expect.

Table 3. Measured valuation variance and accuracy in commercial property.

Sources as cited. The Hager and Lord figures and the Crosby, Lavers and Murdoch paired-valuation data are reported here from Boyd and Irons (2002), which reviews the literature; the Cannon and Cole and RICS figures are taken from the originals.

Three of those rows do work the others cannot.

Cannon and Cole retires the objection that this is all British and all from the 1990s. It is American, commercial, large-sample, and runs to 2010. Its headline is that appraisals sit "more than 12% above, or below, subsequent sales prices that take place two quarters following the appraisal," on institutional-grade property with good transaction evidence. That figure is larger than the ten percent tolerance the English courts apply, which is worth noticing: the measured dispersion of professional practice exceeds the legal margin within which practice is presumed competent.

Crosby, Lavers and Murdoch answers the question in the form it is usually asked. Most accuracy studies compare a valuation against a sale price, which measures the valuation and the market together. That study compared two valuations of the same property by different firms, which is what a client means when they ask why two appraisals differ. One pair in ten differed by more than 20 percent, and about a third differed by more than 10 percent, with no market movement involved at all.

Daniels measures the proposition this paper is actually about. It holds the valuers constant and varies only the difficulty of the property. Mean absolute error rose from 5.3 to 8.9 percent and the share landing within 10 percent fell from 95 to 50 percent. The study is residential, forty years old, and tiny, so it proves nothing on its own. But it is the only design in the literature that isolates complexity, and it points the same way as everything else here: the harder the property, the wider the spread, and a hangar on leased airport land is a hard property.

What remains true, and is stated in Section 10, is that none of this measures hangars. No study has measured appraisal variance on hangars or airport property, and the figures above establish the order of magnitude of the problem in commercial property generally rather than its size in this asset class.

The legal framing is worth more than the percentages. English courts developed a tolerance, expressed in Singer and Friedlander v John D Wood [1977] 243 EG 212 as "generally ten per cent either side of the figure which can be said to be the right figure." In Mortgage Express v Countrywide Surveyors, Judge Ian Hunter QC put the objection to that framing better than the literature does. He preferred not to call the bracket a degree of error "since to be in error, albeit even marginally in error, presupposes that there is a correct value," and described it instead as "the margin within which experienced and competent valuers may reasonably differ in their opinion of the property's value."

The rest of the passage should be quoted, because without it the point does not survive a hostile reading. The judge went on to locate a correct value after all: "the only correct value is what the property actually sells for in an active market," and, for the purpose of testing a valuation against the permissible margin, "having identified the outer limits of the margin, the correct value for this purpose is the median figure." So the objection is narrower than it first appears. There is no correct value knowable in advance, which is why a range is the honest output; there is a correct value knowable afterwards, which is the price. A scope of work is a decision about how much evidence to gather before the second one arrives.

The behavioural literature complicates the picture in a direction worth reporting honestly, and it has to be reported in full or not at all. The expectation that appraisers anchor on a previously supplied expert value was not confirmed: differences ran in the direction consistent with anchoring but "were not statistically significant, suggesting that anchoring may be more subtle than generally believed" (Diaz 1997). The following year the same author tested a different anchor, the appraiser's own prior estimate of the same property, and found it (Diaz and Wolverton 1998). Anchoring on somebody else's number is weak. Anchoring on your own is not. That distinction bears directly on scope, because the appraiser who forms an early view and then gathers evidence is anchored to a figure the file will not reveal, and the discipline that guards against it is scoping the evidence before forming the view rather than after. What has been found is an effect running from the client rather than from a number: appraisers exposed to coercive feedback are more likely to see themselves as price validators, while those receiving positive reinforcement of an objective standard are more likely to see themselves as providers of objective opinions of value (Wolverton and Gallimore 1999). That is a finding about scope as much as about ethics, because a validator scopes to confirm and an appraiser scopes to test.

7.3 Thin markets widen the spread, and the standards say so

The professional standard that describes a hangar in these terms is not American. Addressing when valuation uncertainty becomes material, the global standard identifies "[p]articular characteristics that make it difficult for the valuer to form an opinion of the likely value, regardless of the approach or method used," noting that the asset "may be very unusual, or even unique" and that "[f]or some assets or liabilities, the market may be so limited that there are few, if any, relevant transactions that can be analysed to provide reliable inputs into the valuation" (Royal Institution of Chartered Surveyors 2024, VPGA 10, para. 2.1(a)). The same guidance treats restricted information as a second source of material uncertainty, which is Section 5 of this paper stated as a standard.

It also warns against the response a client sometimes wants, which is a tighter-looking number: "in most cases it is either inappropriate or impractical to reflect [material valuation uncertainty] in the valuation figure quantitatively," and "the inherent risk with quantification of any sort is that it might convey an impression of precision that could be misleading" (VPGA 10, para. 3.3).

The practical consequence for scope is the opposite of the intuition. A property with thin market evidence does not take less work because there is less to look at. It takes more, because every input has to be built rather than observed, and because the report must explain what was not available and why the conclusion is still credible.

8. What Is Not Known About Appraisal Fees

This paper quotes no fees. The reason is not discretion. It is that the public record will not support a number, and the shape of what is missing is worth setting out precisely, because the gap is narrower and more specific than practitioners usually assume.

A federal price series does exist. The Bureau of Labor Statistics has published a monthly producer price index for real estate appraisal services since December 1995 (series PCU5313205313201), and the Census Bureau's Service Annual Survey reports industry revenue under NAICS 531320. What neither publishes is a level. A price index tracks the change in what appraisal services cost; it does not say what an appraisal costs, and it carries no split between commercial and residential work, let alone by property type. An index that rose four percent last year tells a hangar owner nothing about the invoice in front of them.

What does not exist is a published level for commercial work. No trade association fee survey, no peer-reviewed estimate of commercial appraisal fee determinants, and nothing whatever specific to aviation or special-purpose property. Some state appraiser boards have commissioned and published fee surveys, but those are residential and jurisdiction-specific.

There is a structural reason the profession does not publish a commercial fee schedule, and it is antitrust rather than reticence. In 2022 the Federal Trade Commission entered a final order against the Louisiana Real Estate Appraisers Board over its regulation of appraisal fees. A trade body that published a schedule of what its members should charge would be publishing a price list, and the absence of one is a feature of the competitive structure rather than an oversight.

One vendor publishes periodic averages derived from its own order platform, reporting a national average commercial appraisal fee of $2,529 and an average turnaround of 13.3 days for the first quarter of 2024 (LightBox 2024). Those figures circulate widely and should not be relied on as a market estimate. They come from one company's lender-driven order flow; the sampling frame is disclosed, and it is the disclosure that creates the problem rather than solving it, since the frame is order data from over 1,200 banks and credit unions and therefore consists entirely of lender-ordered assignments. The published analyses give no sample size and no property type breakdown, and the reported year-over-year decline mixes a volume effect with a price effect.

Congress has said, in a different context, what counts as evidence of a customary fee, and the lender-order objection is its objection too. For residential work, acceptable evidence is "objective third-party information, including fee schedules, studies, and surveys prepared by independent third parties such as government agencies, academic institutions, and private research firms," and a fee study "shall exclude assignments ordered by known appraisal management companies" (15 U.S.C. 1639e(i)(1)). A statute that excludes management-company order flow from residential fee evidence is not an authority on commercial fees, but it is a considered judgment about the same defect.

The one place American law does address appraisal fees is instructive, because of what it says and where it stops. For consumer credit transactions secured by a principal dwelling, lenders "shall compensate fee appraisers at a rate that is customary and reasonable for appraisal services performed in the market area of the property being appraised," with an express exception: "In the case of an appraisal involving a complex assignment, the customary and reasonable fee may reflect the increased time, difficulty, and scope of the work required" (15 U.S.C. 1639e(i)(1), (i)(3)).

The implementing regulation sets out what a fee may be adjusted for, and the list reads like the argument of this paper: property type, scope of work, turnaround time, appraiser qualifications, appraiser experience and professional record, and appraiser work quality (12 C.F.R. 1026.42(f)(2)). Scope of work and property type sit first and second.

That regime reaches residential mortgage appraisal and nothing else. Commercial and special-purpose appraisal is unregulated as to fee. So the only honest general statement about what a hangar appraisal costs is a description of what moves the scope, and the list Congress wrote for residential work is a serviceable one: property type first, scope of work second.

9. Reducing Scope, and Comparing Proposals

Most of the levers sit with the client, and they are cheap to pull.

Assemble the lease and every amendment, side letter and consent in one file. Know the square footage, door width and height, clear height and year built, and whether anything has been added since. Have three years of rent and expense history if the building is leased. Know what the assessor currently believes the property is, which is frequently not what it is. And identify the intended use and the intended users before the engagement letter rather than after the draft. An appraiser who receives that package can scope accurately; one who has to assemble it will scope for the uncertainty.

The intended use decision deserves particular care because it is asymmetric. An appraiser can scope for the harder use from the start, which costs more once, or scope for the easier use and rebuild later, which costs more twice. Where the use might become a land release, a tax filing or a proceeding, saying so at the outset is the cheaper path even if the harder use never arrives.

On comparing proposals, the useful comparison is scope to scope rather than number to number. Four questions separate proposals that look alike: what does this proposal assume about the ground lease; which approaches to value will be developed and on what reasoning; which intended use and intended users is it built to support; and what site inspection and data collection does it include. Two proposals that answer those differently are not quotes for the same assignment, and the difference in price is reporting that fact.

10. Limitations

The variance literature reported in Section 7.2 is now wider than one country and one decade, but it is still not about hangars. The largest study is American, commercial and runs to 2010; the paired-valuation data is British and from the 1990s; the segment evidence is British and from 2017; the one design that isolates complexity is Australian, residential and from 1983. Two of the figures reach this paper through a review article rather than the original. Together they establish that competent appraisers differ materially on the same asset, and that the gap widens with difficulty and with thinness of market. They do not establish by how much appraisers differ on an American leasehold hangar. A search of academic databases, conference archives and aviation sources found no study that has measured that, which is a gap worth someone's attention and is not filled here.

The fee finding in Section 8 is a negative one, and negative findings of that kind are never conclusive. It is stated narrowly for that reason: a federal price index exists and is named, what is missing is a published level for commercial work, a property type breakdown, and anything at all specific to aviation. A proprietary dataset may exist behind a subscription this search could not reach.

Fire code group boundaries in Section 6.1 rest on the published summary of changes to the 2026 edition of NFPA 409 rather than on the standard itself, which is a paid publication. An industry association has described the same amendment more narrowly, as affecting the Group II ceiling. Anyone relying on a group boundary for a specific building should obtain the standard.

Finally, this paper describes what determines scope in the United States. Nothing in it is a fee quotation, a fee schedule or a representation about any particular assignment, and Section 8 explains why no such figure appears.

11. Conclusion

A hangar appraisal has no list price because the assignment is not a commodity. The profession's own standard places the scope decision with the appraiser, measures it against what competent peers in that assignment type would do and what regularly intended users expect, and forbids the appraiser from letting a client's conditions narrow the work below credibility.

Four things then move it. The ground lease decides what interest is being valued and how much reading it takes to find out. The intended use imports an instrument, and those instruments differ by an order of magnitude in what they demand, from an evaluation below a $500,000 banking threshold to a report that must satisfy a federal agency as a named intended user, a federal acquisition standard, a rule of evidence, or a penalty computed against the appraiser's own fee. The sponsor's willingness to release data sets the hours and occasionally the method. And the building's own characteristics, including a fire code that moved in 2026 and a contamination question that entered required scope on 8 July 2024 without the underlying standard changing a word, expand the work by operation of law rather than by anyone's instruction.

What follows for a client is not a number but a procedure. Supply the lease, state the intended use, find out what the airport will release, and then compare proposals on scope. A proposal that is materially cheaper than the others is usually cheaper because it is scoped differently, and the four questions in Section 9 will show whether that difference is a saving or a deferral.

This paper is research and general information for professionals evaluating aviation real estate. It is not appraisal, legal, or tax advice, and it does not create an engagement. It quotes no fees; scope and fees are set case by case.

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