It’s hard to tell from passing by building sites, like the one for the 24-story Moxy by Marriott hotel in Boston’s Theater District, that the construction industry is changing from even just a decade ago.

But, in fact, the Moxy is a good example of how the trade is transforming thanks to prefabrication, say executives at Boston-based startup, ManufactOn.

The Moxy is “literally on like a postage stamp,” said Brad Hartnagle, who handles sales and marketing for the construction software company. “There’s nowhere to put materials. The plot size is tiny – everything has to be delivered just in time. The more work off-site, the better.”

The Moxy is in a tight place — a 4,000 square-foot lot — at Tremont and Stuart streets, and work can’t block access to area theaters.

Increasingly, for projects like this pieces of buildings are being assembled off-site, carried over by truck, and plopped into residential towers, hospitals, stores and hotels, says Raghi Iyengar, an industrial engineer and chief executive of ManufactOn.

“Instead of bringing raw materials to the job site to do basic construction and have thousands of people on the job site, now the idea is to have all these ‘Lego blocks’ built in off-site factories and then assembled as they come onto the job site,” says Iyengar.

While “prefabrication” – the jargon for pre-built buildings or their parts – has been around for a longtime, he said, it’s only in the past half decade or so that it’s taken off big-time in the industry.

“In the last three, four, five years, there’s been a new upsurge,” he said.

ManufactOn is trying to fill in the missing piece of this trend by providing a key building block: a software that allows developers to coordinate and track their projects and the progress of those prefabricated “Lego blocks,” as well as the handling of traditional materials.

“As more of this work is off-site, the supervisors can’t track it. Typically, they were used to seeing what was going on in front of their eyes. Now, there are 10 different off-site factories, how do you know what is the status, where’s it at, what’s going on, is it going to be delayed? They just don’t have visibility into it and ManufactOn’s whole goal is to address that gap,” said Hartnagle.

The model has made the small Seaport District-based startup and its subscription-based software see increasing demand from builders and others in the industry, said the executives. Current clients include big local and national names in the trades such as Consigli Construction Company, Lee Kennedy Co., Interstate Electrical Services, PCL Construction and Rosendin Electric. Just a week ago, the company formed a partnership with Applied Software, which serves the architecture, engineering, construction and manufacturing industries.

“People can access it where ever they are,” said Iyengar of the cloud-based ManufactOn software service. “It’s a collaborative platform, so (builders) can drive more and more of the work off-site, make things prefabricated and get them delivered just in time to the job site.”

Prefabricated parts could include wall panels, electrical racks, and even rooms, said the CEO.

“There’s the idea of creating entire rooms – an entire bathroom or hotel room – and actually building the room in a factory, bringing it to the job site by truck, and putting it in room by room by room.”

Founded in November of 2014, ManufactOn has so far raised about $4 million in venture capital funding, mainly from its lead investor Brick and Mortar Ventures of San Fransisco. Last fall, Autodesk came in as a strategic investor.

Iyengar had previously worked for Autodesk, helping to put together their construction portfolio, and before that, in the construction and manufacturing side of Intel, from 1988 to 1998.

With customers in Canada and the U.S., Iyengar says the goal is to eventually go global.

When asked whether he envisions going public or getting bought out, the CEO was cagey. But he did say, “Our plan right now is to grow significantly and support our investors…. The reason why we were so excited to have Autodesk come in as a strategic investor is they have a huge initiative globally to drive what they call industrialized construction. … Having said that, we are working with other software players as well in the industry, so we want to make sure that we … have the opportunity to grow significantly. … But in terms of what the future holds, only time will tell. We’ll keep all options open.”

And, he said, things will likely change quickly.

“I would be surprised if in five years from now, there are any projects that are thinking of building 100 percent from the ground up, on the construction site.”