— Your neighbors may not be who you think they are.

According to a recent report on housing in San Marcos, a widely-held preconceived notion is just that — an opinion formed without adequate facts.

For years — decades in fact — most people had assumed San Marcos’ thousands of apartments were occupied primarily by Texas State University students.

But it’s just not true, and city officials say that’s due to both the investment potential of multi-family housing and the lack of affordable single-family homes in the local market.

In fact, only 23 percent (5,791) of residents in multi-family dwellings are students, with the vast majority, 77 percent (19,708), identified as non-students, according to the report presented to the San Marcos City Council by Assistant City Manager Laurie Moyer.

Moreover, the majority (56 percent) of Texas State students don’t live in San Marcos at all. Only 26 percent call the 78666 zip code home and of that, only 18 percent live on campus.

Of those students who do live in town, 44 percent are in multi-family housing, 14 percent in single family housing and 42 percent in on-campus housing.

Those that live out of town come from all over Central Texas, according to the research of the city’s GIS Administrator Joni Hickey, who did her Texas State Master’s Thesis on San Marcos housing trends and is responsible for the numbers in the survey.

To break it down: Hickey found that 14,083 students list San Marcos as their address and 548 list San Marcos Metro (consisting of Luling, Lockhart, Maxwell, Martindale, Driftwood, Wimberley and Dripping Springs); 1,426 are from San Antonio and 714 from San Antonio Metro (Boerne, Comfort, Kerrville, Lakehills, Mico, Rio Medina, Von Ormy, Atascosa, Pleasanton, Floresville, Adkins, Poth, Gillett, Hobson, Stockdale, La Vernia, Saint Hedwig, Cibolo, Converse, Universal City, Schertz, Leesville, Nixon, Cost, Gonzales, Smiley and Shiner); 1,076 from Pflugerville, Round Rock and Georgetown; 1,041 from New Braunfels, 312 from New Braunfels Metro (Kingsbury, Seguin, McQueeney, Marion, Boerne, Kendalia, Bulverde, Spring Branch, Canyon Lake, Blanco and Fischer); 1,006 from Kyle and Buda; 5,659 from Austin and 1,102 from Austin Metro (Taylor, Thrall, Coupland, Lexington, McDade, Elgin, Manor, Bastrop, Smithville, Dell Valle, La Grange, Red Rock, Dale, Schulenberg, Mouston, Harwood, Cedar Park, Leander, Liberty Hill, Marble Falls, Spicewood, Johnson City and Round Mountain).

The report also confirms that Texas State is thriving. Based on an enrollment of 32,572 in the fall of 2010, it is the sixth largest university in Texas, having experienced a 5.74 percent growth rate from the year before. It has the second highest growth rate for universities with more than 25,000 students, and enrollment is projected to be 37,000 by 2015 and 41,500 by 2020.

Given the university’s growth, and regardless of where students live, their daytime presence skews San Marcos much younger than other Central Texas communities. The report gives the city’s population a median age of 23.1 years. In 2000, 37 percent of the population was 15 to 24 years old; in 2010 that had increased to 47 percent.

San Marcos’ workforce also differs from that in most communities. In 2000, 73 percent of residents were not working full-time, as opposed to 27 percent who were.

The median earnings for a full-time employee in 2000 was $34,000; part-timers made a median income of $7,000 — those rates for the Austin Metropolitan Statistical Area (MSA) are 49 percent of residents working full-time and making a median income of $40,460.

Though Business Week magazine rated the city “one of the top 10 places to raise kids in the U.S.,” the majority of San Marcos households are not composed of families.

“San Marcos is a non-family household community,” the report says, with the trend towards non-families rising between 2000 and 2010.

In 2000, the report says, 42 percent of San Marcos households were families compared to 58 percent non-family. By 2010 that gulf had widened to 62 percent non-family households compared to 38 percent families.

In Hays County overall, 77 percent of households are families compared to 23 percent that are not.

Another trend is towards renter-occupied housing as opposed to owner occupied. In 1980 there was almost no difference, with 49 percent of housing units occupied by owners compared to 51 percent occupied by renters.

In 1990, there were 44 percent owner-occupied compared to 56 percent renter-occupied; in 2000, 30 percent owner-occupied compared to 70 percent renter-occupied and in 2010, a mere 26 percent were owner-occupied compared to 74 percent renter-occupied.

Just how disparate that ratio is was borne out in comparison to other “university” towns like Nacogdoches (40 percent owner-occupied compared to 60 percent renter-occupied); Huntsville (38 percent owner-occupied compared to 62 percent renter-occupied); Ames, Iowa (43 percent owner-occupied compared to 57 percent renter-occupied); Davis, California (43 percent owner-occupied compared to 57 percent renter-occupied); Bloomington, Indiana (33 percent owner-occupied compared to 67 percent renter-occupied) and College Station (33 percent owner-occupied compared to 67 percent renter-occupied).

Of those cities, only Nacogdoches and Huntsville have populations smaller than that of San Marcos.