SB 840's Conversion Rules Explained: What the 5-Year and 65% Requirements Mean for San Antonio Investors

If you have been watching San Antonio's real estate market as an investor, developer, or even a curious homeowner, you may have started hearing about SB 840 and the new framework it creates for converting existing buildings into residential or mixed-use properties. Two specific requirements sit at the heart of the law, and understanding them can help you decide whether a property you own, are eyeing, or are thinking about selling could qualify.

First, the building must have been constructed at least five years before the conversion takes place. This single rule immediately shapes which properties are in play. In a fast-growing metro like San Antonio, there is no shortage of older commercial stock—think aging strip centers along Bandera Road in the 78250 ZIP code, mid-century office buildings near downtown's 78205, or underperforming retail corridors in areas like Converse, Kirby, or Live Oak on the northeast side. A brand-new building does not qualify, which keeps the focus on adaptive reuse rather than ground-up development dressed up as a conversion.

Second, at least 65 percent of the converted building must become mixed-use or multifamily residential. That threshold matters enormously in practice. It means a developer cannot gut a vacant grocery store, drop in a handful of apartments on one floor, and call it a day. The residential component has to be the dominant use. A ground-floor coffee shop or small retail suite can still exist in the remaining 35 percent, but the project is fundamentally a housing project. That requirement should reassure neighbors who worry about conversions that look residential on paper but function more like commercial developments with a token apartment or two.

There is a third piece of SB 840 that works alongside these two rules and is worth knowing: cities cannot require more than one parking space per dwelling unit in a qualifying conversion. This may sound like a technical footnote, but for investors it is actually one of the most consequential parts of the law. Parking minimums have historically killed adaptive reuse projects in San Antonio and across Texas. A vintage office building in a walkable pocket of Alamo Heights, Olmos Park, or the 78212 ZIP code near San Pedro Avenue might have the bones to become beautiful apartments, but if the city demands two or three parking spaces per unit, the math rarely works. Stripping that barrier down to one space per unit opens the door to projects that would have been penciled out and abandoned under the old rules.

For investors specifically, the combination of these three provisions creates a clearer path to acquiring and repositioning underperforming assets. If you own a 1990s-era professional building sitting mostly vacant near Loop 410 and Culebra, or a dated neighborhood shopping center in the Judson Independent School District area near Universal City, the five-year age threshold is already cleared many times over. The question becomes whether the building's layout, footprint, and acquisition price allow you to commit 65 percent of the space to residential units while keeping the project financially sound.

For sellers, this law quietly changes the conversation about what your older commercial property might be worth. A buyer who can now point to a legal framework supporting residential conversion may see more value in that building than a traditional commercial buyer hunting for retail tenants in a challenging leasing environment. If you have been sitting on an aging mixed-use or commercial property anywhere from the South Side near Palo Alto College to the Far West Side along Highway 151, it is worth having a candid conversation about whether SB 840 changes your exit strategy.

For renters, the downstream effect is the reason the law exists at all. San Antonio's housing supply has struggled to keep up with the region's growth. Adaptive reuse conversions, when they pencil out, tend to add units faster than ground-up construction because the shell of the building is already standing. More qualifying projects moving forward means more inventory entering the rental market, which over time puts at least some pressure on the upward drift in rents that tenants across Bexar County have felt for several years.

For existing homeowners, the neighborhood-level impact depends heavily on where a conversion happens. A well-executed residential conversion of a long-vacant eyesore can stabilize surrounding property values and bring foot traffic that supports local businesses. A poorly executed one can create parking and traffic headaches, which is exactly why the one-space-per-unit cap applies specifically to qualifying conversions rather than being a blanket citywide change.

The practical takeaway for anyone in the San Antonio market right now is straightforward. If you are an investor, audit your portfolio and your target list with these three numbers in mind: five years old, 65 percent residential, one parking space per unit. If a property checks those boxes, SB 840 may have just made your next deal more viable than it was a year ago.