When it comes to architecture, Boston has an uneasy relationship to the past. The city is full of structures that reflect our rich history, yet we’re also known for demolishing whole neighborhoods in the name of urban improvement. Has Boston learned from its past? Is it doing enough to protect and preserve our architectural gems?

When the Alvah Kittredge House was built in the 1830s, it was majestic — a huge, elegant structure that boasted six ionic columns and anchored a sprawling estate. By the late 2000s, it was a mess — decaying, dilapidated, and on the verge of being condemned. But now, the Kittredge House has been reborn. Recently, I got a tour from Kathy Kottaridis, the executive director of the nonprofit Historic Boston, who led me up the building’s sinuous wooden staircase.

"There was a railing, but not much of one," Kottaridis told me. "In pieces, and various elements on different floors — but for the most part that’s been completely rebuilt."

I would think, knowing nothing about woodworking, that this is not an easy thing to rebuild.

"Not at all, not at all — but such a distinctive feature of the house that it was worth doing," she said.

That’s just one detail of the extreme makeover that Historic Boston completed earlier this year. After three years of fundraising and renovation, the Kittredge House is back to its former glory, with a pristine Greek Revival exterior — think the White House, but smaller — and marbled floors and ceilings. Kottaridis says that because it’s still standing, an important part of the neighborhood’s history is still alive.

"It was one of the first houses to be built here after the American Revolution, when this was very much a rural area," she said. "This house, if you look at the historic photographs, was a much bigger sprawling estate on a large piece of land. It would have been a big deal to live up here."

The Kittredge House is just one example of Boston mobilizing to preserve its architectural heritage. In the so-called Innovation District, most of the attention’s been on the boxy new buildings along the waterfront. But many businesses flocking to South Boston are choosing the old warehouses of the Fort Point Channel historic district — created in 2009 after years of lobbying by preservationists.

"These are the original maple floors, 1905," said Jim Kelliher, CFO of software company LogMeIn. "We just resanded them all down."

LogMeIn used to be in Woburn. Kelliher says that when the company moved into the city, the throwback aesthetics of Fort Point’s buildings were a major draw.

"A big part of this building is the character of this building," he said. "You see those metal doors down there. You see an old fireplace that we left in place that we just repainted, right? We wanted to keep the character of the building and the character of the space, and we felt creating a high-tech space within that would be pretty cool."

That’s exactly how businesses should be thinking, says Greg Galer, the head of the Boston Preservation Alliance.

"Historic buildings are about new as well as old," Galer said. "They can be economic drivers, really."

Now, Galer wants more developers to embrace preservation as a commercial asset.

"The character is what makes Boston unique," he said. "The character of the city is one of Boston’s most significant economic engines and social engines and cultural engines. It’s not just here in Fort Point. There are areas in JP and Roxbury — they all have their own special character. And if we start erasing those, Boston isn’t Boston anymore."

Yet erasure remains a fact of life. With its Art Deco facade, the Shreve, Crump & Lowe building on Boylston Street is one of the Back Bay’s iconic structures. But an attempt to have it designated a Boston landmark failed — and now, it’s slated for demolition. Chinatown’s Dainty Dot building and Jamaica Plain’s Home for Little Wanderers were both locally beloved, but succumbed to the wrecking ball anyway. Now, preservationists fear for Boston’s oft-reviled City Hall — which Mayor Marty Walsh proposed demolishing during his campaign last year. Galer, of the Boston Preservation Alliance, warns that would be a mistake.

"City Hall’s a difficult building to discuss, to try to convince people it’s worthy of saving," he said. "But you have to remember that not too long ago, Victorian buildings that we love and adore were considered hideous and ugly, and were torn down left and right."

Something to ponder as we weigh which buildings should live — and which ones can die.

Local architect Mark Pasnik discusses why Boston should do more to protect its historic architecture — and how preservation is actually smart business for the city.