I remember the exact moment: 2:17 p.m. on May 14, 2024. A client who had been a professional acquaintance for years called with a problem. Her firm had just discovered that a city incentive program for vacant office buildings could close its application cycle on June 1. If they missed it, the next window might not open for another year. She had one question: Could Gensler’s office-to-residential conversion practice, in 14 days, prove that an aging 1987 office tower could become housing?
The short answer was yes. The real answer is more complicated.
I’m a senior project manager at Gensler. Over the past four years, I’ve helped guide more than 30 adaptive reuse studies. A number of those involved Gensler office-to-residential conversion work in different U.S. markets. I do not say that to impress you. I say it because I want you to know the difference between what I thought before those projects and what I believe now: old buildings always find a way to surprise you.
Here’s the story of one of the most uncomfortable, illuminating two-week sprints of my career.
The Call
The building in question was a seven-story, 210,000-square-foot office property in downtown Austin. The client didn’t own it yet. She was under contract to buy it at a major discount, but her financing and zoning assumptions disappeared with the first term sheet. The new plan was to turn the building into roughly 120 rental apartments, with 15% of them designated affordable. That affordability component was what made the city incentive relevant.
The incentive program offered fee waivers and density bonuses for conversions that preserved affordable housing. But it also required a preliminary application that included a concept design package, indicative unit layout, and a realistic cost estimate. That package—the kind of thing we normally take six to eight weeks to prepare—was due in exactly 14 calendar days.
Look, I know that sounds like a self-inflicted deadline. But this is how commercial real estate works. Opportunities don’t wait for your internal capacity. And part of what lets a firm like ours respond is having integrated teams that can move when the calendar goes sideways.
The Building and the Catch
At first glance, the building looked promising. It had a 30-foot column grid, 9-foot-6-inch ceiling heights, and large windows with decent daylight penetration. A typical office floor plate was about 60 to 70 feet deep from window to core. For residential conversion, that is almost exactly the depth you need to run a double-loaded corridor with units on both sides. If you know what you’re doing, this can work.
The catch? We had almost no reliable documentation.
The ownership had gone through two bankruptcies, and the file—what little remained—contained only a 1995 architectural plan set and some partial structural notes. There were no as-built drawings for the mechanical, electrical, or plumbing systems. We were designing against shadows.
That’s the first thing I want anyone to understand about office-to-residential work: the building is an unreliable narrator. You have to assume nothing.
The Surprise on Level Three
We sent a team to field-verify the building on the second day. That’s when I made my first wrong assumption. I assumed that if the column grid was 30 feet on one floor, it would be 30 feet on every floor. Nothing in that assumption turned out to be true.
Level three contained a transfer slab. It was built in 1980s style to accommodate a former banking hall that had double-height space and a different structural system. The columns above it didn’t line up with the columns below. What looked like a standard four-bedroom unit in one place could not legally fit in another because a 30-inch-deep transfer beam ran directly through the middle of the master bedroom ceiling.
Let me repeat that: a thirty-inch-deep concrete beam, passing through what would have been the bedroom. There was no way to hide it without raising the floor or dropping the ceiling—both of which would have killed the headroom and blown the budget.
We had to rethink the first three floors as entirely different plan types. The geometry that worked on floors four through seven was useless below. That wasn’t a design problem. It was a building condition that you can only solve when project architects and interior designers sit next to structural engineers before the pretty pictures are made. Which, honestly, is how every conversion should be done.
Why Interior Design Had to Lead
People often think of interior design in an office-to-residential conversion as the finishing stage: kitchen, bathroom, paint, fixtures. That’s a misunderstanding. In a conversion, the interior layout is the feasibility engine. You don’t start with the facade or the architectural concept. You start with the residential unit plan.
For this project, Gensler’s interior design team took the lead. They tested seven unit mix strategies in three days. Which arrangement yielded enough two-bedrooms for the rental market? Which could survive the transfer slab? Where could we place plumbing cores so that each floor could be served efficiently by new vertical risers?
We also had to think about bathroom venting. In an office building, there are few toilet vents, since offices rely on centralized systems. In a residential building, every bathroom needs ventilation. You cannot simply move a drain a few feet and call it good. This is the kind of issue that haunts conversion projects if the interior design team is not in the room. Which, yes, sounds self-serving, but I can’t tell you how many generic templates ignore these constraints.
One moment stands out. Our construction management lead, who had been helping us estimate the cost of adding a new bathroom core, pulled the drawing aside and said: Even if you fit 26 units on this floor, the plumbing risers will need a shaft that eats one-third of your corridor. Move it to the center and you lose the light. Move it to the side and you create a 70-foot corridor. Which one do you want? In a 30-year-old structure, every choice is a trade-off.
That’s why I keep telling clients: no design is good until it survives a construction review. Gensler interior design is not decoration. It is a construction strategy wearing nicer clothes.
Back to the Calendar
By day seven, we had stabilized the overall concept: 122 units, 19 of them affordable, a central corridor, plumbing cores placed in each tower quadrant, and a phasing plan that let the client build as existing tenant leases expired.
Then came the fire damper problem. Our mechanical engineer flagged that the existing vertical ductwork between floors was never designed for residential compartmentalization. Some units needed fire-rated duct wrap. Others needed rerouted ducts altogether. That added roughly $40 per square foot to the estimate—a number I didn’t expect and couldn’t hide.
This was the moment where I was tempted to tell the client what she wanted to hear. If we removed the wrap from the estimate, the project might look feasible enough to win the application, and maybe we could deal with it later. But later is where projects go to die.
I’m not a structural engineer or a fire-protection specialist, so I won’t pretend I could resolve the damper conflicts myself. What I could do was make sure the right people were in front of the right problems before the submission deadline. And that is also a kind of expertise.
We submitted the complete concept package at 11:58 p.m. on May 29, 2024. Two days later, the client received preliminary approval and the right to move into the formal permitting phase. She later told me that if we had missed that deadline, the seller’s agreement would have expired and she would have lost a non-refundable deposit of $300,000.
Not Every Building Is Worth Saving
Here’s the part I want any developer or building owner to take seriously. Office-to-residential conversion is not a magic lever that works on every empty office tower. It works on buildings that were designed or retrofitted with certain characteristics: deep floor plates, generous window spacing, structural grids that align with residential modules, and enough ceiling height to hide mechanical runs.
If a building is shallow—say, 45 feet wide from window to core—you can still get density, but each floor tends to produce weird-shaped units that the market won’t rent. If the floors are so deep that they wipe out two-thirds of your daylight, the units feel like caves. If the existing structure cannot support the added weight of new residential partitions and plumbing, the cost to stiffen it will swallow your returns.
I’d rather tell a client this building is not a good fit for homes than force a scheme that underperforms for years. Because no architecture firm—not ours, not anyone’s—can design away the physical limits of an old building.
What This Taught Me
Three lessons stand out, and I think they are transferable beyond just Gensler or real estate.
- Verify the structure before you fall in love with the concept. A plan based on incomplete as-builts is not a plan; it’s a hope.
- Let interior design lead the feasibility study. Unit mix, corridor placement, plumbing cores, and daylight access decide whether the conversion is profitable. Elevating the building’s exterior comes later.
- Get a construction voice in the room while the design is still mobile. The construction manager doesn’t kill the design; they save it from being unbuildable.
I don’t have a perfect industry-wide statistic on how many conversion projects die in due diligence. I can only tell you what our internal data shows: after 30+ conversion studies, we have recommended not proceeding on about one in four buildings. Some clients thank us for that honesty. Some hate it. But every client is better off knowing before they spend months or millions on the wrong shell.
If you’re sitting on an office building and wondering whether it could work as housing, start with that question—not with the renderings. And when the timeline compresses to 14 days, make sure the people you bring in have already seen the hidden places where office buildings lie. Because they always lie.
