Historic Tax Credits and Qualified Rehabilitation Expenditures: A Practitioner's Guide to the 20% Federal Rehabilitation Credit

Key Takeaways

What Is the Federal Historic Tax Credit

The federal historic tax credit is a dollar-for-dollar reduction in federal income tax liability available to owners and certain long-term lessees who undertake a substantial rehabilitation of a certified historic structure. The credit equals 20% of qualified rehabilitation expenditures, as defined under IRC Section 47. Since the Tax Reform Act of 1986 consolidated the rehabilitation credit into its current form, the HTC has facilitated the rehabilitation of more than 47,000 historic buildings nationwide, generating over $144 billion in private investment according to the National Park Service Federal Tax Incentives program.

The credit serves a specific economic function: it bridges the gap between the cost of rehabilitating a historic building according to preservation standards and the amount a market-rate developer would spend on a comparable new construction project. Historic rehabilitation is inherently more expensive than new construction. Existing structural conditions, hazardous material abatement, window restoration, facade preservation, and the constraints of working within existing footprints all add cost. The 20% credit partially offsets those incremental costs, making adaptive reuse financially competitive with ground-up development.

The HTC is not a grant. It is not a deduction. It is a credit, meaning it reduces tax liability on a dollar-for-dollar basis. For a corporate taxpayer in the 21% bracket, $1 of tax credit is worth significantly more than $1 of tax deduction (which would save only $0.21 in tax). This is why the HTC is syndicated: developers sell the credits to investors with federal tax liability, generating equity for the project.

IRC Section 47 Mechanics

The statutory foundation for the rehabilitation credit is IRC Section 47, which establishes the credit rate, defines qualified rehabilitation expenditures, sets the substantial rehabilitation test, and specifies the ratable claim period. Prior to the Tax Cuts and Jobs Act (TCJA) of 2017, IRC Section 47 also provided a 10% credit for non-historic buildings placed in service before 1936. That 10% credit was eliminated by the TCJA. Only the 20% credit for certified historic structures remains.

The TCJA also changed the timing of the credit claim. Before 2018, the full 20% credit was claimed in the taxable year the rehabilitated building was placed in service. The TCJA modified this to a five-year ratable claim: the credit is spread equally over five taxable years, beginning with the year the building is placed in service. This change significantly affects the time value of the credit for investors, reducing the present value of the credit by approximately 10-15% depending on the investor's discount rate.

Eligible property types

The building must be a "certified historic structure" as defined in IRC Section 47(c)(3). This means it must be:

• Listed individually on the National Register of Historic Places, or
• Located within a registered historic district and certified by the Secretary of the Interior (through the NPS) as being of historic significance to the district.

The building must also be depreciable. This means the credit is available for income-producing properties (commercial, industrial, rental residential) but not for owner-occupied residences. A developer converting a historic warehouse into market-rate rental apartments qualifies. A homeowner renovating a listed Victorian house does not.

The building must be substantially rehabilitated. Cosmetic renovations, minor repairs, and maintenance work do not qualify. The substantial rehabilitation test (discussed in detail below) imposes a minimum spending threshold that must be met within a defined measuring period.

Credit rate and calculation

The credit equals 20% of qualified rehabilitation expenditures. The calculation is straightforward:

Table 1. Credit calculation for a rehabilitation with $8.5M in qualified expenditures. The 20% rate applies to QREs only, not total project cost.

The simplicity of the formula is deceptive. The complexity is in determining what qualifies as a QRE, meeting the substantial rehabilitation test, and securing NPS certification. Each of those requirements is a potential disqualification.

Qualified Rehabilitation Expenditures

Qualified rehabilitation expenditures are the universe of costs that qualify for the 20% credit. IRC Section 47(c)(2) defines QREs as amounts properly chargeable to a capital account for property that is (1) nonresidential real property, residential rental property, or real property with a class life of more than 50 years, (2) in connection with the rehabilitation of a qualified rehabilitated building, and (3) incurred during the measuring period.

In practical terms, QREs include the hard construction costs and associated soft costs of rehabilitating the existing building. The critical word is "rehabilitation." Work that constitutes new construction, enlargement, or site improvements outside the building envelope does not qualify. The line between rehabilitation and new construction is where most QRE disputes arise.

Hard costs that qualify

The following categories of hard construction costs are generally treated as QREs when they relate to the rehabilitation of the existing building:

• Structural engineering and repair. Foundation stabilization, structural steel reinforcement, floor system rehabilitation, load-bearing wall repair. On a typical historic office conversion, structural work ranges from $15 to $45 per square foot depending on the extent of deterioration.
• Exterior envelope restoration. Facade cleaning and repointing, window restoration or historically appropriate replacement, cornice repair, roof replacement. Window restoration alone can run $800 to $2,500 per window on buildings with original wood or steel sash windows.
• Interior demolition and reconstruction. Removal of non-historic interior partitions, framing of new interior walls (within the existing footprint), drywall, plaster restoration where historic plaster is character-defining. Interior work typically represents 25-35% of total QREs.
• Mechanical, electrical, and plumbing (MEP). Complete replacement of HVAC systems, electrical service upgrade and rewiring, plumbing risers and distribution, fire protection and sprinkler systems. MEP is often the single largest QRE category, representing 30-40% of total rehabilitation costs on buildings where all systems require full replacement.
• Elevator installation or modernization. Installation of new elevators within existing shafts or new shafts cut within the existing building envelope qualifies. Adding an elevator tower that extends beyond the original footprint may not qualify as QRE (the exterior addition portion would be excluded).
• Hazardous material abatement. Asbestos removal, lead paint abatement, and other environmental remediation within the building are QREs. Site contamination remediation outside the building envelope is not.
• Accessibility improvements. ADA-required modifications including ramps (within the building), accessible restrooms, elevator installation, and code-required egress improvements within the building.

Soft costs that qualify

Certain professional fees and indirect costs associated with the rehabilitation also qualify as QREs:

• Architectural and engineering fees. Fees for the design of the rehabilitation project, including structural engineering, MEP engineering, and historic preservation consulting. These typically run 8-12% of hard costs. On a $7M hard cost rehabilitation, architectural and engineering fees of $700,000 to $840,000 would qualify.
• Construction management fees. Fees paid to the general contractor for overhead and profit, as well as construction management or owner's representative fees directly related to the rehabilitation.
• Permitting and inspection fees. Building permit fees, plan review fees, and code inspection fees related to the rehabilitation work.
• Construction period interest. Interest on construction loans during the rehabilitation period is a QRE. This is a significant line item on larger projects where construction periods run 18-24 months. On a $10M construction loan at 8.5% for 18 months, construction interest can exceed $900,000.
• Construction period taxes and insurance. Property taxes and builder's risk insurance during the rehabilitation period qualify.
• Historic preservation consulting. Fees paid to historic preservation consultants for NPS application preparation, SHPO coordination, and preservation plan development.

QRE Eligibility: Qualifying vs. Non-Qualifying

The distinction between qualifying and non-qualifying expenditures is one of the most litigated areas in HTC practice. The IRS, NPS, and Tax Court have developed a substantial body of guidance on these distinctions. Understanding them before the project begins is essential, because QRE classification drives the credit amount, which drives investor equity, which drives the capital stack.

The enlargement exclusion

One of the most frequently misunderstood QRE rules involves enlargements. Under IRC Section 47(c)(2)(B)(i), expenditures attributable to the enlargement of an existing building are specifically excluded from QREs. An "enlargement" means any increase in the total volume of the building. This includes:

• Adding new floors above the existing roofline
• Constructing lateral additions that extend the building footprint
• Excavating below the existing foundation to create new below-grade space
• Enclosing previously open areas (such as converting an open courtyard into usable interior space)

The enlargement exclusion creates real complications in adaptive reuse projects where the developer wants to maximize rentable area. A common example: a developer rehabilitating a four-story historic warehouse wants to add a rooftop penthouse level. The cost of the penthouse structure, MEP systems serving that floor, and the interior buildout of the penthouse units would all be excluded from QREs. The remaining four floors of rehabilitation work would still qualify.

The practical implication is that the developer must maintain separate cost allocations for the historic rehabilitation (QRE-eligible) and the new construction (non-QRE) components. The contractor's cost breakdown must support this allocation. General conditions, overhead, and profit must be allocated proportionally between the two components. A single lump-sum contract that does not distinguish between rehabilitation and new construction work will create problems during a QRE audit.

The personal property exclusion

QREs must relate to real property, not personal property. Items classified as personal property under the tax code do not qualify even when they are physically installed in the building. The line between real property and personal property in the context of building rehabilitation is not always obvious:

Table 2. Real property vs. personal property classification for common building components. The general test is whether the item is permanently affixed to and integral to the building structure.

The Substantial Rehabilitation Test

Before any credit can be claimed, the rehabilitation must be "substantial." This is not a subjective assessment of the project's scope. It is a quantitative test defined in IRC Section 47(c)(1)(C): qualified rehabilitation expenditures during the measuring period must exceed the greater of:

• The adjusted basis of the building (and its structural components) as of the beginning of the measuring period, or
• $5,000

The adjusted basis is the purchase price of the building (not including land) minus accumulated depreciation. For a building that was purchased years ago and has been depreciated, the adjusted basis may be quite low, making the test easier to satisfy. For a recently acquired building, the adjusted basis will be closer to the purchase price.

The measuring period

The default measuring period is 24 months. The taxpayer selects any 24-month period during which the QREs must exceed the adjusted basis threshold. If the rehabilitation is phased (as large projects often are), the taxpayer may elect a 60-month measuring period, provided the rehabilitation is conducted pursuant to a written plan that identifies all phases.

The measuring period election is irrevocable. Choose carefully. A 24-month period works for most single-phase rehabilitations where construction is completed within two years. The 60-month period is reserved for projects where the rehabilitation scope genuinely requires more than 24 months, such as a multi-building historic campus or a phased rehabilitation of a very large structure.

Worked example: applying the test

Consider a developer who acquires a certified historic office building for $3,500,000 (inclusive of land). The purchase price is allocated as $800,000 to land and $2,700,000 to the building. The building has not been depreciated by the current owner (it was just purchased). The substantial rehabilitation test requires:

Table 3. Substantial rehabilitation test for a recently acquired building. QREs must exceed the building's adjusted basis of $2.7M within the measuring period.

If the developer plans $8,500,000 in QREs, the test is easily satisfied (QREs of $8.5M exceed adjusted basis of $2.7M). But if the developer planned only $2,500,000 in rehabilitation work, the project would fail the test and no credits would be available for any of the expenditures.

Timing and the measuring period

The timing of expenditures within the measuring period is critical. Only QREs incurred during the selected measuring period count toward the test. If a developer selects a 24-month period from January 2026 through December 2027, expenditures incurred in December 2025 (before the period) or January 2028 (after the period) do not count. The developer must coordinate the construction schedule and the draw schedule to ensure that enough QREs are incurred within the measuring period.

"Incurred" generally means the point at which the expenditure is properly chargeable to a capital account under the taxpayer's method of accounting. For accrual-basis taxpayers, this is when the liability becomes fixed and determinable (generally, when the work is performed and accepted). For cash-basis taxpayers, this is when the expenditure is paid. In either case, the key is that the cost must be incurred within the measuring period, not merely contracted for.

NPS Part 1, Part 2, Part 3 Certification

National Park Service certification is mandatory for the 20% federal HTC. The NPS Federal Tax Incentives program administers a three-part certification process, conducted jointly with the relevant State Historic Preservation Office (SHPO). Each part serves a distinct function, and the entire process typically runs 12-18 months from initial filing to final certification.

Part 1: Evaluation of Significance

Part 1 certifies that the building is a "certified historic structure." If the building is individually listed on the National Register, Part 1 is essentially a formality: the NPS confirms the listing and issues the certification. The real complexity arises with buildings in registered historic districts that are not individually listed. For these buildings, Part 1 requires a determination that the building contributes to the historic significance of the district.

The Part 1 application (NPS Form 10-168a) requires photographs, maps, a description of the building's architectural features, and a statement of significance. The SHPO reviews the application first and forwards it to the NPS with a recommendation. Approval times typically range from 30 to 90 days, though complex cases can take longer.

Part 1 should be filed before commencing any rehabilitation work. While it is possible to file Part 1 concurrently with Part 2, beginning work before receiving Part 1 approval introduces risk: if the building is determined not to be a contributing structure, no credit is available regardless of how much has been spent.

Part 2: Description of Rehabilitation

Part 2 is the most substantive and consequential step. The application (NPS Form 10-168b) describes the proposed rehabilitation work in detail, including architectural drawings, specifications, material selections, photographs of existing conditions, and a narrative explaining how the proposed work is consistent with the Secretary of the Interior's Standards for Rehabilitation.

The Secretary's Standards, codified at 36 CFR 67, are the ten principles that govern what can and cannot be done to a certified historic structure while still qualifying for the credit. The standards emphasize:

• Preserving distinctive materials, features, finishes, and construction techniques
• Repairing rather than replacing historic features where possible
• Making new additions and alterations distinguishable from the historic fabric
• Treating new work so that it can be removed in the future without damaging the historic materials

Part 2 rejection is the single most common failure point in the HTC process. Typical reasons for rejection or conditional approval include:

• Replacement of character-defining windows with modern units that do not match the historic profile, sightline dimensions, or material
• Removal of interior features such as original staircases, ornamental plaster, or lobby finishes that define the building's historic character
• Facade alterations including new openings, infilled openings, or incompatible cladding that disrupts the historic appearance
• Incompatible new additions that overwhelm or compete with the historic structure in scale, massing, or materials
• Roof alterations that change the historic roofline or add visible mechanical equipment without screening

Part 3: Request for Certification of Completed Work

Part 3 is filed after the rehabilitation is complete. The application (NPS Form 10-168c) documents that the completed work conforms to the work described and approved in Part 2. The Part 3 application includes photographs of the completed rehabilitation, with specific views corresponding to the conditions documented in Part 2.

Part 3 certification is generally straightforward if the completed work matches the approved Part 2 scope. Problems arise when field conditions required changes from the approved plans. Any material deviation from the Part 2 approval should be communicated to the SHPO and NPS through an amended Part 2 filing before submitting Part 3. Submitting a Part 3 that shows unapproved changes can result in denial of certification for the entire project.

The NPS issues the Part 3 certification (or denial) to both the taxpayer and the IRS. The IRS will not allow the credit if Part 3 certification has not been received.

Timeline summary

Table 4. NPS certification timeline. The total process from Part 1 filing to Part 3 certification typically runs 18-30 months, including the construction period.

Five-Year Ratable Credit Claim

Under the TCJA amendment to IRC Section 47, the 20% rehabilitation credit is claimed ratably over five taxable years, beginning with the taxable year in which the qualified rehabilitated building is placed in service. "Placed in service" means the building is in a condition of readiness and availability for its intended use. For a building rehabilitated into office space, this is generally when the building receives a certificate of occupancy and is available for lease. For residential rental, it is when the first units are available for occupancy.

Year-by-year schedule

For a rehabilitation generating $2,000,000 in total credits ($10,000,000 in QREs at 20%), placed in service in 2026:

Table 5. Five-year ratable credit claim schedule for a $2M HTC. Each year, 4% of QREs (20% credit divided by 5 years) is claimed.

Present value impact

The five-year ratable claim reduces the present value of the credit compared to the pre-TCJA single-year claim. Using a 7% discount rate, $2,000,000 in credits claimed over five years has a present value of approximately $1,720,000 (86% of face value). This present value reduction is reflected in credit pricing: investors pay less per dollar of credit than they did under the pre-TCJA regime when the full credit was available in year one.

Current HTC credit pricing ranges from approximately $0.80 to $0.92 per dollar of credit, depending on deal quality, investor demand, project location, and whether the credits are paired with state historic credits. According to Novogradac's HTC resource center, average pricing for federal HTC equity has stabilized in the mid-$0.80s as of early 2026, reflecting both the five-year claim discount and strong investor demand for rehabilitation projects in opportunity zones and urban cores.

Recapture rules

If the building is disposed of or ceases to be a qualified rehabilitated building within five years of being placed in service, previously claimed credits are subject to recapture under IRC Section 50(a). The recapture amount decreases by 20% for each full year the building is held after being placed in service:

• Disposition in year 1: 100% recapture of credits claimed
• Disposition in year 2: 80% recapture
• Disposition in year 3: 60% recapture
• Disposition in year 4: 40% recapture
• Disposition in year 5: 20% recapture
• After year 5: no recapture

Recapture applies not only to outright sale but also to changes in use (converting from income-producing to owner-occupied), certain partnership transactions, and changes in the tax-exempt use percentage. The five-year recapture period is a holding requirement that investors and developers must respect in their partnership agreements.

Basis Adjustment Under IRC 50(c)

A critical and often overlooked aspect of the HTC is the basis adjustment required by IRC Section 50(c). When a rehabilitation credit is claimed, the depreciable basis of the building is reduced by the full amount of the credit. This is not a reduction in QREs; it is a reduction in the basis used for depreciation calculations going forward.

Consider a building with $10,000,000 in QREs generating a $2,000,000 HTC. Under IRC 50(c), the depreciable basis of the rehabilitation expenditures is reduced from $10,000,000 to $8,000,000. This reduction affects the annual depreciation deduction and, by extension, the investor's total tax benefit from the project.

Table 6. IRC 50(c) basis adjustment. The $2M credit reduces the depreciable basis by $2M, lowering annual depreciation by approximately $51,000 per year for commercial property on a 39-year straight-line schedule.

For investors, this means the HTC is not a pure windfall. The credit is partially offset by reduced depreciation deductions over the life of the building. The net benefit of the HTC to an investor at a 21% corporate tax rate is the $2,000,000 credit minus the present value of lost depreciation deductions ($51,282/year for 39 years at 21% tax rate). In practice, the credit still provides substantial net benefit, but the reduced depreciation must be modeled accurately in the investor's return calculations.

Interaction with LIHTC

When HTC and LIHTC are layered on the same project (a common structure for affordable housing in historic buildings), the basis adjustment has additional implications. The HTC basis reduction under IRC 50(c) reduces the depreciable basis of the rehabilitation expenditures, but it does not reduce the eligible basis for LIHTC purposes. The LIHTC eligible basis is calculated independently under IRC Section 42(d), using the full QRE amount before the IRC 50(c) reduction. This is a favorable interaction that preserves the full LIHTC credit amount even when HTC is also claimed.

However, the two credits cannot be claimed on the same expenditures without careful structuring. The typical approach is a "twinning" structure where a master lease or dual-entity arrangement allows one entity to claim the HTC and a separate entity to claim the LIHTC. The structuring of HTC/LIHTC layered deals requires specialized tax counsel and is beyond the scope of this article, though the economic benefit of layering both credits on a single project can be substantial. A $15M rehabilitation of a historic building into affordable housing can generate $3M in HTC equity plus $8-12M in LIHTC equity, depending on the credit type and pricing.

HTC Equity Structure and Capital Stack

Historic tax credit equity flows into the project through a partnership structure specifically designed to allocate the tax benefits (credits and depreciation) to the investor while allowing the developer to retain operational control. The typical structure involves four parties:

• Developer (general partner or managing member): contributes the project, manages the rehabilitation, operates the building after completion. Holds a small ownership interest (typically 0.01% to 1%) but controls all management decisions.
• Investor (limited partner or investor member): contributes equity in exchange for tax credits and depreciation deductions. Holds 99% or more of the partnership interest for tax allocation purposes. Often a large bank, insurance company, or corporate entity with significant federal tax liability.
• Syndicator: aggregates investor capital and multiple projects into a fund, performs due diligence, structures the partnership, monitors compliance. Charges a fee (typically 10-15% of the equity raised).
• National Park Service: certifies the historic significance of the building and the consistency of the rehabilitation work with the Secretary's Standards. Not a party to the partnership, but its certification is the prerequisite for the credit.

Equity pay-in schedule

HTC investor equity is not paid in a lump sum at closing. It is disbursed in installments tied to project milestones, similar to LIHTC pay-in schedules but typically with fewer installments:

• Admission/closing (10-20%): Paid when the investor is admitted to the partnership and the construction loan closes.
• Construction completion (20-30%): Paid when the rehabilitation work is substantially complete and the building receives a certificate of occupancy.
• Part 3 NPS certification (40-50%): The largest installment, paid when the NPS issues the Part 3 certification confirming that the completed work is consistent with the Secretary's Standards. This is the critical milestone for the investor because without Part 3 certification, no credit is available.
• Cost certification and tax return filing (10-20%): The final installment, paid when the project's cost certification is complete and the first tax return claiming the credit is filed.

The heavy weighting of equity toward the Part 3 certification milestone creates a timing gap for the developer. Rehabilitation costs are incurred throughout the construction period, but the majority of investor equity does not arrive until after construction is complete and Part 3 is approved. The developer bridges this gap with a construction loan, and the bridge interest on the gap between construction draws and equity receipts is a real cost that must be included in the pro forma.

Capital stack impact

HTC equity typically covers 12-18% of total development cost on a standalone HTC deal (without LIHTC layering). This is a meaningful source of equity, but it does not dominate the capital stack the way 9% LIHTC equity can. The remaining capital stack typically includes:

• Senior debt (conventional or CMBS): 50-65% of total development cost, sized to the stabilized NOI at a 1.20-1.40x DSCR
• HTC equity: 12-18% of total development cost
• State HTC equity (if available): 5-10% of total development cost
• Developer equity or mezzanine debt: 10-25% of total development cost, filling the remaining gap
• Gap sources: EB-5, New Markets Tax Credits, opportunity zone equity, historic preservation grants, TIF, or other local incentives

On layered HTC/LIHTC deals, the capital stack looks fundamentally different. The LIHTC equity covers 25-65% of TDC (depending on 4% vs. 9%), the HTC equity covers another 12-18%, and the combined tax credit equity can exceed 70% of TDC. These deals require less conventional debt and developer equity, which is why they are attractive for affordable housing preservation in historic buildings.

State HTC Programs

Approximately 37 states offer their own historic tax credit programs that can be layered on top of the federal 20% HTC. State credit rates, eligibility requirements, and transferability rules vary significantly. The most generous state programs can nearly double the total credit available for a rehabilitation project.

Table 7. Selected state historic tax credit programs. Rates and caps current as of 2026. Transferability determines whether credits can be sold to third-party investors, which is critical for equity syndication.

Stacking federal and state credits

When federal and state HTC programs are both available, the combined credit can be substantial. A rehabilitation in Virginia with $10,000,000 in QREs would generate:

• Federal HTC: 20% of $10,000,000 = $2,000,000
• Virginia state HTC: 25% of $10,000,000 = $2,500,000
• Total credits: $4,500,000 (45% of QREs)

At combined credit pricing of approximately $0.85 per dollar of federal credit and $0.70-$0.80 per dollar of state credit, this generates approximately $3,500,000 to $3,700,000 in total tax credit equity, representing 37% of QREs as equity. Without the state credit, the equity would be approximately $1,700,000 (17% of QREs). The state credit more than doubles the equity available.

However, stacking introduces complexity. Some state programs require that the state credit base be reduced by the federal credit amount (preventing double-dipping). Others apply independently to the same QRE base. The investor market for state credits is often thinner than for federal credits, meaning state credit pricing can be lower and more volatile. Each state's program has its own application process, certification requirements, and compliance periods.

Worked Example: $15M Office Rehabilitation

To illustrate how these components fit together in practice, consider a developer rehabilitating a 45,000 square foot, four-story certified historic office building in Richmond, Virginia. The building was originally constructed in 1920, is individually listed on the National Register, and has been vacant for eight years.

Project cost breakdown

Table 8. Project cost breakdown for a $15M historic office rehabilitation. QREs total $11M, representing 73% of total development cost. Non-qualifying items include acquisition, land, site work, permanent financing, syndication, and reserves.

Substantial rehabilitation test

The building's adjusted basis at the beginning of the measuring period is the acquisition price of $2,250,000 (building only, excluding land). QREs of $11,000,000 easily exceed the adjusted basis of $2,250,000. The test is satisfied with substantial margin.

Credit calculation

Table 9. Combined federal and state HTC for the Richmond rehabilitation. Total credits of $4.95M represent 33% of total development cost.

Capital stack

With credit pricing of $0.87 per dollar of federal credit and $0.75 per dollar of Virginia state credit, the tax credit equity is:

• Federal HTC equity: $2,200,000 x $0.87 = $1,914,000
• Virginia HTC equity: $2,750,000 x $0.75 = $2,062,500
• Total HTC equity: $3,976,500

Table 10. Capital stack for the $15M Richmond rehabilitation. Combined HTC equity covers 27% of TDC, reducing the developer's required equity contribution from 42% (without credits) to 15%.

Without the historic tax credits, the developer would need $7,200,000 in equity (48% of TDC after senior debt). With the credits, the equity requirement drops to $3,223,500 (21.5% of TDC, including the deferred developer fee). The $3,976,500 in HTC equity reduces the developer's cash equity by more than half, fundamentally changing the return profile of the deal.

Common Mistakes

These errors appear repeatedly in HTC underwriting and application practice. Each can delay or disqualify the credit:

• Starting work before Part 1 approval. If the building is later determined not to be a certified historic structure, all expenditures are wasted from a credit perspective. File Part 1 first and wait for approval before committing significant capital.
• Failing to distinguish rehabilitation from enlargement costs. The contractor's schedule of values must separately identify costs attributable to the rehabilitation of the existing building versus costs of any new additions. A single lump-sum contract makes QRE substantiation difficult during an audit.
• Ignoring the basis adjustment under IRC 50(c). The credit reduces the depreciable basis of the building, which reduces annual depreciation. Investor return models that claim the full credit without reducing the depreciation overstate the investor's return.
• Miscounting the measuring period. The 24-month (or 60-month) period must be carefully selected and tracked. QREs incurred outside the measuring period do not count toward the substantial rehabilitation test. Construction delays that push expenditures past the end of the measuring period can disqualify the project.
• Treating the NPS Part 2 review as a formality. Part 2 is the most common failure point. Developers who submit Part 2 applications without engaging a historic preservation consultant frequently receive denials or extensive conditions that add months to the timeline and require costly redesign.
• Including personal property in QREs. Kitchen equipment, removable fixtures, and freestanding items are personal property and do not qualify. The cost segregation study (often performed for depreciation purposes) can help identify the real property vs. personal property classification, but the QRE determination must use tax law classification, which may differ from the cost segregation result.
• Assuming state credits follow federal rules. Each state program has its own QRE definition, application process, and compliance requirements. Some states define QREs more narrowly than the federal program. Others have caps, sunset dates, or additional certification requirements. Each state program must be evaluated independently.
• Underestimating the bridge loan cost. Because HTC equity is paid in installments (with the largest tranche after Part 3 certification), the developer must bridge the gap between construction expenditures and equity receipts. Bridge interest on a $2M equity gap for 12-18 months at 8-10% adds $160,000 to $300,000 to the project cost. This must be in the pro forma.

How to Model It

An HTC pro forma differs from a standard acquisition or development model in several important respects. The following components must be present and properly linked:

QRE Schedule

A line-by-line breakdown of every project cost, classified as QRE or non-QRE. This is the foundation of the credit calculation. The schedule should tie to the contractor's schedule of values and the project's certified public accountant (CPA) cost certification. Every hard cost and soft cost line item needs a QRE/non-QRE flag. Totals should be reconciled against the sources and uses.

Substantial Rehabilitation Test

A dedicated calculation showing the building's adjusted basis, the measuring period start and end dates, the total QREs incurred during the measuring period, and a pass/fail determination. This should be a live formula that updates as cost estimates change. If the QRE total drops below the adjusted basis threshold, the model should flag the failure prominently.

Credit Calculation

Total QREs, the 20% rate, the total credit amount, and the five-year ratable claim schedule. If state credits are also claimed, a parallel calculation for the state credit with its own rate, cap, and eligibility rules. The credit pricing assumption (dollars per dollar of credit) should be a clearly labeled input that flows through to the equity amount.

Investor Pay-In Schedule

The timing of equity installments tied to milestones (closing, construction completion, Part 3 certification, cost certification). The gap between construction draws and equity receipts should drive a bridge loan calculation. Bridge interest is a real cost and must be included in the sources and uses.

IRC 50(c) Basis Adjustment

The depreciation schedule must reflect the basis reduction equal to the credit amount. Annual depreciation should be calculated on the reduced basis ($QREs minus $credit), not the full QRE amount. This affects the investor's depreciation deductions and therefore the investor's total return.

Investor Return Analysis

The investor's internal rate of return (IRR) and total return should reflect: (1) the five-year ratable credit claim, (2) reduced depreciation from the IRC 50(c) basis adjustment, (3) the equity pay-in timing, and (4) any residual value or exit proceeds at the end of the compliance period. Investor yields for HTC deals currently range from 6.5% to 8.5%, depending on credit quality, project risk, and the availability of state credits.

Related Articles

This article is part of the tax credits underwriting series. Each article covers a specific credit program or structuring technique:

• LIHTC 101: How the Program Works. The Low-Income Housing Tax Credit explained from the ground up. How 4% and 9% credits generate equity, and when each is used.
• The LIHTC Capital Stack. Soft debt, deferred developer fee, HOME funds, and gap financing in affordable housing deals.
• Opportunity Zones and Qualified Opportunity Funds. How OZ incentives work and how they interact with historic tax credits in designated census tracts.
• Acquisition/Rehab with 4% Bonds. Modeling existing property deals with rehabilitation credits, including HTC layering on historic affordable housing.