A 35-year-old Phoenix office tower is about to become one of the most closely watched adaptive reuse projects in the American Southwest. LaPour Partners, the Las Vegas-based hospitality developer, has unveiled plans to convert One Arizona Center, the 19-story, 351,600-square-foot Class A office building at 400 E. Van Buren St. in downtown Phoenix, into a 340-room JW Marriott hotel. The $200 million project will begin interior demolition in early 2027, with an opening targeted for 2029. That is the news. The more important story is what it signals about the Arizona design market and the specific kind of professional expertise that is becoming genuinely valuable here.

Why This Building Could Be Converted When Others Cannot

Adaptive reuse sounds like a concept that applies to any underperforming building, but the engineering reality is far more selective. One Arizona Center’s viability as a hotel candidate comes down, in significant part, to its floor-to-floor heights. The tower was built with approximately 12 feet 6 inches of floor-to-floor clearance, a specification that was generous for a 1989 Class A office building and one that is critical for hotel conversion work.

The plumbing problem. Converting office floors to hotel rooms requires installing vertical plumbing chases at roughly 25 to 30-foot intervals, one per room, through concrete slabs that were never designed to accommodate them. Buildings with tight floor-to-floor clearances cannot fit the chase depth and still meet minimum finished ceiling heights for a luxury brand. One Arizona Center’s extra height creates the working room that makes this technically feasible.

The acoustic challenge. Office buildings are designed around large, open structural bays. Hotel rooms require acoustic separation at every party wall, including at columns and beams that rarely align with where room boundaries need to fall. Designing sound assemblies around existing structure, without shrinking rooms below JW Marriott’s standards, is a discipline that separates experienced hospitality conversion architects from those who have built their portfolios entirely on ground-up projects.

The view asset, preserved. LaPour’s decision to place meeting and event spaces on the 18th and 19th floors rather than guest rooms is strategically well-considered. The panoramic views from those floors are the building’s most irreplaceable feature. Using them as a backdrop for conferences and events creates a differentiator for the property while reducing the acoustic and plumbing complexity that hotel rooms on those floors would introduce.

Phoenix Has Built a Conversion Market, and the City Is Helping

The One Arizona Center project arrives as Phoenix has established itself as one of the more active adaptive reuse markets in the country. National commercial real estate tracking places Phoenix among the top 15 U.S. cities for office-to-residential conversion projects, with the metro area’s pipeline representing at least six active efforts. The City of Phoenix’s Adaptive Reuse Program formalizes that momentum with tangible support: streamlined permitting pathways, modified code interpretations for existing structures, and fee reductions of up to $7,000 per eligible project. For design professionals, a city that has institutionalized support for adaptive reuse is signaling that this work has a future here, and that building the expertise to navigate that environment pays off across multiple projects, not just one.

LaPour’s position in this project includes an advantage that deal terms alone do not convey. The firm previously developed the AC Hotel Phoenix Downtown within the same Arizona Center complex. That history means existing familiarity with the building’s systems, the property’s ownership structure, and the downtown Phoenix hospitality demand patterns. The planned JW Marriott will sit across E. Van Buren from the 1,000-room Sheraton Phoenix Downtown, anchoring what is becoming the most concentrated hotel corridor in the city’s urban core. For LaPour, this is their fourth hotel development in the Phoenix area since the early 2020s, a pace that reflects deliberate, compounding knowledge of the market rather than opportunistic entry.

What This Means for Arizona Design Professionals Right Now

The One Arizona Center conversion illustrates a shift that is accelerating across the Arizona market: adaptive reuse is no longer a specialty sidebar in commercial design. It is becoming a primary vehicle for urban infill, and the architects, interior designers, and project managers who have built specific expertise in existing-building work are having a different set of client conversations than those who have not.

Team selection is the critical early decision. Bringing an adaptive reuse project to an architect whose experience is entirely in ground-up construction is a risk that most project budgets do not model accurately. Existing-structure documentation, discovery of unexpected mechanical conditions, and coordination around systems with decades of deferred maintenance are disciplines that require specific practice. Arizona developers evaluating conversion plays should vet architecture firm experience in adaptive reuse with the same rigor they apply to general contractor selection.

Interior design is equally specialized. A ground-up JW Marriott gives the interior designer a clean envelope and complete control over adjacencies. A conversion assigns them existing column spacing, non-negotiable structural penetrations, and fixed floor-to-floor heights that constrain millwork and ceiling detail options. The designers who find opportunities within those constraints, rather than fight them, are the ones whose project pipelines will grow with this market.

The signal for building owners. One Arizona Center was a vacancy-challenged office tower before LaPour’s intervention. The $200 million conversion signals that underutilized Class A office buildings now have a credible exit path that did not exist five years ago, and that path runs through design firms and hospitality developers who have the specific experience to execute it. For any Arizona property owner sitting on a building with similar characteristics, floor-to-floor heights above 12 feet, downtown or infill location, proximity to existing hospitality demand, the relevant question is no longer whether a conversion is possible. It is whether you have the right professionals at the table to evaluate it honestly.