Over the past 37 years, William Lavicka has made some big changes to the Near West Side — by keeping it the same.

Starting with his own home on Jackson Boulevard just east of Ashland Avenue, he took big chunks of a block-long stretch of run-down old mansions and gave them the love they needed to thrive.

From there, he moved across the city, repairing dozens of old homes as well as churches, athletic facilities and more. As the hobby became a career, Lavicka made bundles of friends in the city’s preservationist community, and the occasional adversary.

But this year he’s decided to get out of the rehabbing and construction business in order to take on one final project — himself.

Lavicka was diagnosed with colon cancer six months ago, and he’s been through six chemotherapy sessions so far. He doesn’t talk about the prognosis — saying he’ll get a better idea from his doctor soon — but it’s been rough enough so far that he’s decided to close up his toolbox.

“It’s chewing away at me,” Lavicka said. “I’m out of it at this point. I gave it a shot there. I did a lot of good work.”

Lavicka started his rehab career in 1974 when he bought his stately but rundown old mansion on Jackson with a group of other urban-renewal-minded young people who had been spurred on by a University of Illinois - Chicago architecture professor.

The stately stretch of mansions on the 1500 block of Jackson had been spared from the wrecking ball — unlike so many others on the Near West Side — because they were whorehouses, Lavicka said.

While many of the nearby homes had been knocked down in a misguided attempt to keep black people out of the area, the local aldermen had been too intimidated, or perhaps respectful of the madams, to try to knock down their places of business.

But by the 1970s, they were out of the business of prostitution and mostly just older women running boarding houses — and many were ready to move out.

Lavicka, a recently returned Vietnam veteran, decided to buy what he now calls “the mother house,” right in the middle of that block, and renovate it. But after a few months of watching contractors unproductively work on the home, he decided to quit his job as an engineer at ComEd and quarterback the job himself.

That was the start of his career. As his neighbors saw the work he’d done restoring his beautiful old house, they asked him to help with theirs. Eventually, he did eight other houses on the block.

“From this house, all the other properties kind of grew,” Lavicka said. “A lot of other people were talkers, and I was the actor.”

The move was a surprise to the city, which was “shocked” that people would want to move into a rundown block in the middle of the Near West Side, Lavicka said. So they worked with him, narrowing Jackson and banning street parking to make the strip more appealing.

“Everyone was leaving Chicago,” Lavicka said. “There were drunks sleeping in my front yard. But it wasn’t a dangerous neighborhood, just a poor one.”

Jonathan Fine, head of Preservation Chicago, credits Lavicka and his cohorts with laying the groundwork for his organization today.

“It proved that who we now call ‘young urban professionals’ would live in the city, and they were very capable of revitalizing neighborhoods,” Fine said. “Historic preservation played an incredibly important role in urban revitalization; in fact, it played a premiere role. These people proved that these buildings could be made viable again.”

Lavicka has been an inspiration for Fine since Preservation Chicago was founded 10 years ago.

“Being a preservationist can be really demoralizing sometimes. We don’t win a lot of battles — we lost a lot,” Fine said. “But Bill’s seen it all, and he’s been through hundreds of fights. He kept plugging away and plugging away and saving buildings. That gave us hope.”

At least one thing has changed in recent years: Lavicka gained an ally in city hall. In fact, he lives on the 1500 block of Jackson as well: Ald. Bob Fioretti (2nd).

“He’s a true pioneer and a true preservationist,” Fioretti said. “He always made sure his voice was heard no matter what, and he helped bind our block together.”

Fioretti was diagnosed with cancer about a year ago, and the two have bonded over that. However, Fioretti’s health has improved as Lavicka’s has worsened recently.

“I’ve been with him since he disclosed it,” Fioretti said. “He’s undergoing a tough fight — my prayers and thoughts are with him every day.”

Lavicka’s most recent project, an effort to turn Washington Park’s Raber House, at 5760 S. Lafayette Ave., into a functioning vineyard, recently fell flat when the local alderman, Willie Cochran (20th), didn’t sign off on the idea. Lavicka’s still fired up about it, but he said he just doesn’t have the energy to keep pursuing it at this point.

“He really didn’t understand the idea of having that spark that would get the neighborhood moving,” Lavicka said. “I hate to plan stuff that doesn’t go through. It’s kind of a bummer.”

Even though he’s stepping down from rehabbing buildings, he’s still got tons of materials on hand from his decades of work. Over the years, he raided ornate old buildings for their quality hardwood materials — banisters and doors, in particular. Sitting in his home, atop his piano, is a serpent he made out of curved handrails that he didn’t have use for elsewhere.

He’s also got a huge stash of dozens and dozens of massive doors, as well. Some of them are in his back house (carriage house), others in a nearby storage facility.

When asked what he’ll do with them now, he thought for a moment, then said with a grin that he wanted to take them with him when he leaves this world. As with so many of his ideas, it had a historical context.

“I suppose you could stack up 50 feet of doors underneath me,” Lavicka said. “Set me on fire like a Viking.”