Flagstaff Heritage Commission approves two historic projects amid HB 2720 duplex reclassification debate
FLAGSTAFF, ARIZONA — March 24, 2025

Flagstaff Heritage Commission approves two historic projects amid HB 2720 duplex reclassification debate

Heritage Preservation Commission approved two significant historic district projects while grappling with controversial new state housing law interpretations and process documentation concerns.

State Housing Law Triggers "Semantic" Duplex Reclassification Dispute as HPC Approves Two Historic Projects

The Heritage Preservation Commission on March 24 unanimously approved adaptive work at two historic properties while engaging in heated debate over whether the city's reinterpretation of duplex regulations to enable multiple accessory dwelling units under state law HB 2720 distorts legislative intent or pragmatically implements a new mandate.

The dispute centered on 603 West Birch Avenue, where property owners propose demolishing a deteriorated garage and constructing a 715-square-foot detached accessory dwelling unit (ADU), plus a 650-square-foot interior ADU within the existing duplex structure. The design challenge: state law requires single-family dwellings to have two ADUs, but the site currently contains a duplex—historically two separate units. The city's solution: reclassify the duplex as a single-family dwelling with an attached interior ADU, thereby unlocking permission for a second detached ADU.

Key Speeches

"The two units in the original duplex are 650 square feet each. They're identical. How does one become primary and the other an accessory?" — Commissioner Duffy

"Every single family is entitled to have two ADUs under House Bill 2720. The applicant has the ability to convert the duplex into a single family home with an attached ADU." — Tiffany Antall, Zoning Code Manager

"What I would see rather see is it changed to a single family dwelling in name rather than in fact and see one of those doors openings closed and torn off and lose some of that. It's still going to read as a duplex as you walk through the neighborhood, right?" — Commissioner Duffy

"There is no requirement in the state law to rename duplexes as single family with an interior ADU. That's a city of Flagstaff decision, and I think as a city we have to revisit that because things are what they are." — Commissioner Wester

"We are following our zoning code. The code has always allowed for uses of buildings to change, so as long as it was a use that was permitted in the zone, the building could change." — Tiffany Antall

Timeline

Applicant presentation: Michael Cuddy, project manager for Insomnia Cookies, and Kevin Gore, project architect, explained the design's compatibility: the new 15-foot ADU is intentionally shorter than the existing 19-foot structure; it features matching roofing, windows, and Hardy Board siding. The deteriorated garage—constructed 40 years after the duplex, with rotted framing, non-existent foundation, and chronic flooding—cannot be salvaged. Commissioner Buckham confirmed the structure's lack of historic significance.

Staff recommendation: Bethany H and Tiffany Antall detailed the regulatory pathway. Originally, before HB 2720 took effect (November 2024), the applicant would have required rezoning to add density. The new state law—requiring at least one attached and one detached ADU on every single-family dwelling—prompted the city to rewrite its code. The duplex can be reclassified to single-family status if one unit becomes an interior ADU (up to 800 sq ft) and a second, detached ADU is constructed. Bethany noted: the code allows an ADU up to 800 square feet, or up to 75% of the principal dwelling size if the owner wants to exceed 800 square feet. In this case, both duplex units are roughly 650 square feet, so the designation of one as an interior ADU satisfies the requirement. The city kept the 800-square-foot floor for existing historic properties to avoid rendering lawful ADUs non-conforming under Prop. 207.

Public comment: One speaker, Jesse Dinges, recalled taking piano lessons at the building decades ago when it housed John Hall's Piano Exchange. He asked the commission to preserve the structure's historical character.

Council discussion: The debate consumed roughly 90 minutes and revealed deep disagreement over state-law interpretation and process precedent.

Commissioner Duffy challenged the logic: "You're calling something not what it is and to get around the state law, and I just think that's really odd." She cited the statute explicitly—HB 2720 states that "at least one attached and one detached accessory dwelling unit" is permitted on a "single family dwelling." Yet the existing structure is demonstrably a duplex, with two doors, two identical units, and 100 years of designation as a duplex. "Where is that in the code?" she asked repeatedly.

Antall responded that the city's zoning code has always permitted changes of use: a duplex can be reclassified to single-family if the owner complies with density and design standards. The interior ADU provision—not explicitly mentioned in the state statute but triggered by Arizona's mandate to allow two ADUs per lot—creates the legal pathway. However, Duffy and Commissioner Wester pressed: Does the state law's reference to "single family dwelling" mean a structure originally built as, and long designated as, a duplex cannot be rebranded mid-project to exploit ADU incentives? Antall acknowledged the concern would likely recur as similar projects arrive: "We're seeing this quite a lot now, where people are looking to have additional units and the density doesn't allow for them… duplexes now converted to single family homes."

Commissioner Wester added a zoning-code argument: "The City Zoning code clearly says that you can't put an accessory dwelling unit with a duplex." She asked why the applicant didn't simply maintain duplex status and rezone for the ADU, rather than reclassify. Bethany H explained that reclassification through the building permit process is faster than rezoning—but Duffy objected: "If we approve it they are breaking the law… if it hasn't been reclassified yet."

The commission's solution, suggested by Vice Chair Hayes, was to condition approval on completion of the reclassification process. Commissioner Buckham moved to approve with the stipulation that the duplex be reclassified as a single-family dwelling with an interior ADU before the HPC's approval became final. This protected the commission from approving an ADU on a structure still legally classified as a duplex.

Commissioner Horn raised a parking concern: the plans designate two parking spaces in front of the proposed detached ADU for the "single-family dwelling," while showing no walkway or access path from those spaces to the detached ADU's front door on Birch Avenue. Kevin Gore clarified that ADUs no longer require parking under the new code, and that residents could park in front of either building and walk through the interior. Commissioner Horn was not fully satisfied but did not object.

Vote: 7–0, with the condition that reclassification be completed.

Opposition

Number of speakers against: None directly; concerns raised by commissioners, not public.

Main concerns:

  1. Reclassification appears to circumvent state law's plain language requiring "single family dwellings," which duplexes are not.
  2. The city's interpretation allows any duplex to be renamed single-family if one unit is designated interior ADU, creating precedent for widespread rebranding without genuine change of use.
  3. Parking and site-design logic is awkward: ADU residents must park in front of the duplex unit, with no clear pedestrian path.
  4. No justification in the state statute for the city's choice to allow interior ADU plus detached ADU on a legally renamed structure.
  5. Process risk: if commissioners approve design now, and reclassification fails later, the HPC will have authorized work on a non-qualifying site.

Most compelling argument: Commissioner Duffy's repeated invocation of the statute: "Wouldn't the Bill be the final [authority]? The Bill passed the house, passed the Senate, and is signed. HB 2720 states that at least one attached and one detached accessory dwelling unit is a permitted use [on a] single family dwelling." The structural asymmetry—two identical 650-sq.-ft. units, both looking like duplex halves—makes the reclassification feel nominal.

Support

Number of speakers for: None from the public; staff and applicant presented case.

Support arguments:

  1. State law mandates two ADUs per single-family lot; the city must provide a pathway.
  2. Existing code allows change of use if the new use is permitted in the zone; single-family is permitted in the historic townsite.
  3. Interior ADU size (up to 800 sq ft) is not required to be smaller than the principal unit under the new state law.
  4. The design itself is compatible: shorter building, matching materials, sympathetic to the neighborhood.
  5. The garage demolition removes a non-historic, flood-prone structure and improves site safety.
  6. Practical necessity: the duplex cannot be developed for additional units under duplex rules; reclassification is the only lawful path under the new state mandate.

Organized groups: None identified.

Project Details

Case number: Not stated in transcript.

Applicant / developer: Property owners (names not provided); project managed by Michael Cuddy (Insomnia Cookies project manager); architect Kevin Gore.

Attorney: None identified in transcript.

Location / address: 603 West Birch Avenue, Flagstaff.

APN: Not stated in transcript.

Current zoning → Proposed zoning: Historic Townsite District; zoning classification remains the same. Use change: duplex → single-family dwelling with interior ADU (pending reclassification).

Density / units / square footage:

Changes from previous version: Not applicable; first HPC review of this design iteration.

Vote Breakdown

Final: 7–0

Yes: All present commissioners (Chair Dale, Vice Chair Hayes, Commissioners Buckham, Buram, Dominguez, Horn, Wester).

No: None.

Abstentions / absences: Commissioner Duffy abstained from the minutes vote (unrelated item) but voted yes on this approval.

Outcome & Next Steps

The commission approved the Certificate of Appropriateness for demolition of the garage and construction of the new detached ADU, conditional upon the applicant's completion of the reclassification of the duplex to a single-family dwelling with an interior ADU. The applicant indicated the reclassification would be submitted to the city "this week." Planning and Zoning will review the reclassification as part of the building permit process.

Controversies & Context

State preemption and city interpretation: Arizona's HB 2720 (signed into law in 2024) mandates that municipalities allow at least one attached and one detached ADU on every lot with a single-family dwelling. The statute does not explicitly address whether a legally existing duplex can be reclassified mid-project to unlock ADU rights. Flagstaff's city staff interpreted the law to permit reclassification through the building permit process, while reserving the formal reclassification determination for the Planning Department. The Heritage Preservation Commission has no formal say in the reclassification; it approves only the design of the ADU and demolition.

Precedent concerns: Commissioners recognized this is likely the first of many similar cases. If approved, it signals that any duplex or other multi-unit structure in Flagstaff can be reclassified to single-family status if one unit is designated an interior ADU (up to 800 sq ft), unlocking a second detached ADU. This could reshape the city's housing stock, particularly in historic districts where infill is constrained by lot size and density rules.

Historic-district impact: The townsite district has been infilled multiple times. Legacy families have already ceded land for density. The new state law, combined with the city's reclassification pathway, introduces a new dynamic: existing duplexes can be converted to single-family-plus-two-ADU configurations without rezoning, potentially increasing density and altering neighborhood character.

Process risk: No formal reclassification application or hearing is required under the city's current code; the change happens through the building permit. The HPC has no mechanism to revisit or condition the reclassification itself. If Planning denies the reclassification after HPC approval of the design, the certificate becomes moot. Vice Chair Hayes and Commissioner Buckham addressed this by conditioning the HPC approval on reclassification completion—a safeguard that may not legally bind the Planning Department but signals the commission's expectation.

Second Major Item: 15 North Laro Street Facade Renovation & Retroactive Window Filling

The commission also approved an updated Certificate of Appropriateness for 15 North Laro Street, a historic property that had undergone facade work approved in April 2024. The project initially included an interpretive sign (approved, with QR code linking to online history now hosted on the city website). In the months following, the property team filled in an upper rear window and added a rain gutter—without prior HPC approval.

Timeline

Staff presentation: City Planner Sarah Dector (Acting Historic Preservation Officer) reported that work on the window and door had already been completed. The upper rear window was filled in due to water infiltration; an adjacent door opening had been filled earlier with what Dector characterized as administrative approval by her predecessor, though no formal Certificate of No Effect (exemption) was documented—only email authorization. The rain gutter was a minor addition and could have been approved administratively.

Why the retroactive ask: Project architect Kevin Gore called city staff in December to inquire about the filled window and learned it had already been filled in. The project team sought retroactive Certificate of Appropriateness approval to memorialize the work.

Staff recommendation: Approve the updated Certificate, with conditions: (1) locate and preserve photographs of the original window; (2) paint the filled window and door openings a contrasting color (or darker shade of the existing facade color) to visually distinguish the original openings and show what was there historically.

Commission concerns:

Commissioner Wester objected to the precedent: "This is the second one of these we've had in a matter of months where somebody's already gone ahead and done something and then they come back and ask forgiveness instead of following the process… I'm a little less tolerant of this… I don't want to set a precedent that yeah just do what you want and then HPC will say it's okay later."

Commissioner Buckham asked: "Do we know why the window was filled in pre-approval… because I think I read that it would be damaging to reverse it so kind of what happens if we don't approve something that's already happened?"

Commissioner Horn raised a second concern: the previous approval of the door filling was not properly documented, and allowing another work-then-seek-approval case could encourage further disregard for the process. She also noted the building is on the rear and less visible, but the precedent remains problematic.

Public comment: None.

Applicant response: Michael Cuddy (project manager) and Kevin Gore explained that water was pooling and ice was decaying the wood structure around the window and door. The window opening extended down to the roof of a bathroom addition ("backpack"), requiring it to be shortened by at least 8 inches to achieve proper waterproofing. Rather than allow continued water damage, the team filled the opening. They have photographs of the original window and offered to provide them to staff.

Gore suggested painting the filled openings in a "slightly darker version of the building color, a little more gray, think of it as a shadow rather than a missing tooth"—distinguishing the original openings without screaming that something's not there.

Vote: Initial motion (7–0) to approve with condition to photograph the original window. Commissioner Horn then moved to supersede with a new motion (7–0) requiring: (1) photograph documentation, AND (2) painting the filled window and door in a darker shade of the facade color to visually distinguish them.

Opposition

Number of speakers against: None from public.

Commission concerns:

  1. Retroactive approval sets a dangerous precedent.
  2. The previous door-filling approval was not properly documented; no formal exemption certificate was issued.
  3. If this case is approved, future applicants may assume they can do work first and seek approval later.
  4. The building official should have required HPC approval before issuing permits for changes visible from the public right-of-way.

Support

Number of speakers for: Staff and applicant.

Support arguments:

  1. Water damage threatened structural integrity; filling was a preservation measure.
  2. The rear facade is not primary and less visible to the public.
  3. No original historic window materials were salvageable; reversing the fill would require new construction, not restoration.
  4. The interpretive sign (already approved) provides historical context and educational value.
  5. The conditions (photograph documentation and color differentiation) adequately mitigate the precedent concern by ensuring the original openings remain visible and documented.

Project Details

Case number: Not stated in transcript.

Applicant / developer: Anthony Rosales (landlord); project team includes Michael Cuddy (Insomnia Cookies project manager) and Kevin Gore (architect).

Attorney: None identified.

Location / address: 15 North Laro Street, Flagstaff (historic townsite district).

APN: Not stated in transcript.

Current zoning: Historic Townsite District.

Changes from original April 2024 approval:

Vote Breakdown

Final (superseding motion): 7–0

Yes: All present commissioners.

No: None.

Abstentions / absences: None.

Outcome & Next Steps

Updated Certificate of Appropriateness approved with conditions: (1) locate and file photographs of the original window with staff to create a historical record; (2) paint the filled window and door openings in a contrasting or darker shade of gray to distinguish the original openings and prevent them from reading as solid facade. The interpretive sign, designed with QR code, is pending installation and will be posted on the front facade once exterior painting is complete.

Controversies & Context

Process precedent: The retroactive approval, even with conditions, troubled commissioners who worry it signals acceptance of work-first-approval-later applications. However, staff argued that the project team proactively called to ask about proper procedure once the window was filled, and the building official had issued permits based on structural necessity (water damage). The distinction between "proactive inquiry" and "forgiveness after the fact" was debated but not fully resolved.

Documentation gap: The previous door-filling approval was never formally documented in HPC records or as a Certificate of No Effect. Commissioners expressed frustration that staff exemptions (allowed under code for minor work) are not consistently tracked. Deputy City Clerk Georgana Stacy acknowledged that the acting HPO's email approval should have been more formally recorded.

Historic preservation trade-off: Commissioners recognized that reversing the window fill would require new construction, not true restoration, and that stopping ongoing water damage is also preservation. The condition to paint the openings a darker shade represents a compromise: acknowledging the original fenestration while accepting the functional fill.

Third Major Item: Process & Documentation Concerns

Near the close of the meeting, Commissioner Horn raised broader concerns about minutes documentation that reverberated throughout the session.

Abstention from Minutes Approval

When the commission voted to approve the March 19 minutes, Commissioner Horn abstained. She explained:

"The reason I'm abstaining now from approving minutes is because they have no memorialization of what happened other than who voted. I think that is something that we really need to do like we used to do—is to have accurate minutes available for people to read."

She cited two concerns: (1) action-only minutes fail to record the reasoning behind decisions, creating a void in the historical record; (2) the city's reliance on YouTube video-only records poses two problems—citizens cannot efficiently search a 2–3-hour video for relevant items, and Google's ownership of the video creates a collection-management issue, as Google (not the city) controls what happens to the video long-term.

City Clerk Response

Stacy Saltsburg (Communication and Civic Engagement Director; City Clerk) and Deputy City Clerk Georgana Stacy acknowledged the tension. They explained:

Stacy noted:

"The legal requirement as it applies to all minutes and as it's required within the open meeting law is actually pretty straightforward… who attended the meeting, who spoke, what the action was, what time you started, what time you ended, and which of the commission members were present. That is all that is legally required. Now often times we will include some additional information to help tell that story a little bit, but we will adhere to what's required legally and we will adjust as necessary."

However, she committed to working with commission liaisons to improve practices and bring consistency across boards.

Historical Preservation Argument

Commissioner Duffy reinforced Horn's concern with a preservation angle:

"When I started on the commission however long ago we actually had minutes and then we would read them… I think not having a paper record… those are going to be lost 10 years from now. Will anybody be able to watch them 20 years? How long would they last?… [For] ad administrative work, we should be doing this for our records for perpetuity, which is what we should be doing with our records."

Saltsburg agreed that electronic preservation is fragile: "I have a CD and I'm like I have no idea how to even get the stuff off of this anymore. I go to my IT folks and they're like we don't have a CD drive."

The city committed to exploring improved minute-taking practices within resource constraints and to updating the commission on progress.

Land Availability and Suitability Study Briefing

The commission also received a briefing on the city's Land Availability and Suitability Study and Code Concept Report—a project addressing the city's dual declared emergencies: housing and climate. Tiffany Antall (Zoning Code Manager) presented three development scenarios that model how changes to density, parking, street width, and sustainable-design incentives could affect housing production and carbon-neutrality goals.

Key findings:

Commission feedback: Commissioner Duffy cautioned against one-size-fits-all density; historic districts like Townside and South Side have been infilled repeatedly and should be treated differently. Commissioner Wester suggested studying actual parking behavior in established neighborhoods (visual observation) before mandating reductions. Commissioner Buckham noted that affordable housing must remain a priority—market-rate production alone will not serve lower-income households.

Next steps: The city will refine final code recommendations by year-end, informed by public comment and commission feedback.

Khara House Move & Preservation Updates

Sarah Dector reported progress on the Khara House project (South Side), a historic 1905 dwelling slated for relocation and adaptive reuse:

Commissioner Wester raised a concern: the adjacent staging lot sits in the flood zone, limiting long-term placement options. The Route 66 realignment project may eventually remove the flood designation, but the city cannot wait that long. A permanent home for the house remains uncertain.

Other updates:

Duration

Other Notable Items

Grants & Sign Approvals: The historic signs and facade grant program has $15,000 available for FY 2025; no new applications received yet, though at least one pending application is expected next month. An interpretive sign with QR code for 15 North Laro Street is approved and in production.

SHIPO Training & Conference: Commissioners are encouraged to register for the National Alliance of Preservation Commissions (NAPC) conference later in year; registration is live. Commissioner registration fees may be waived if attending as an individual (not organizational member). A follow-up design-review training with instructor Ariana Urban is tentatively scheduled for summer 2025.

Open Meeting Law and Conflict of Interest: Deputy City Clerk Georgana Stacy provided a refresher on open meeting law compliance, quorum requirements, meeting posting, and substantial vs. remote conflict of interest. The session underscored commissioners' role in making recommendations to Council and the importance of proper documentation and procedure.