A four-story apartment building destined to house grad students went up in four days in July, including beds, sinks, sofas, and stoves. It is slated to open this month.

Imagine a four-story apartment building going up in four days, and from steel.

It happened in Berkeley, a city known for its glacial progress in building housing.

Check out 2711 Shattuck Ave. near downtown Berkeley. Four stories. Four days in July. Including beds, sinks, sofas, and stoves.

How?

This new 22-unit project from local developer Patrick Kennedy (Panoramic Interests) is the first in the nation to be constructed of prefabricated all-steel modular units made in China. Each module, which looks a little like sleekly designed shipping containers with picture windows on one end, is stacked on another like giant Legos.

The project, initially approved by the city in 2010 as a hotel, then re-approved in 2015 as studio apartments, will be leased to UC Berkeley for graduate student housing. Called Shattuck Studios, it’s slated to be open for move-in for the fall semester.

“This is the first steel modular project from China in America,” Kennedy said, adding that new tariffs on imported Chinese steel hadn’t affected this project.

The modules were shipped to Oakland then trucked to the site. Kennedy notes that the cost of trucking to Berkeley from the port of Oakland was more expensive than the cost of shipping from Hong Kong.

The modules are effectively ready-to-go 310-square-feet studio apartments with a bathroom, closets, a front entry area, and a main room with a kitchenette and sofa that converts to a queen-size bed. They come with flat-screen TVs and coffee makers.

“In order to be feasible, modular construction requires standardized unit sizes and design, and economies of scale,” Kennedy said.

The complex has no car parking, but 22 bicycle parking spots. It has no elevator, and no interior common rooms except hallways, but has a shared outdoor patio/BBQ area. ADA accessible units are on the ground floor.

Floors in each unit are bamboo and tile. The appliances are stainless steel. The bathroom has an over-sized shower. The entry room has a “gear wall” for hanging backpacks, skateboards, bike helmets. Colors are grays and beiges and light browns.

“Our units reflect the more austere, minimalist NorCal sensibility,” Kennedy said, during a recent tour of the complex. “Less but better.”

The modules were stacked on a conventional foundation. Electricity, plumbing, the roof, landscaping and other infrastructure were added.

Using prefab material is supposed to be less expensive than building from scratch, Kennedy said. He had anticipated significantly lower costs by going prefab for this project.

But the savings haven’t been as great as expected, he said. “Sixty-five to seventy-five-percent of the construction costs are still incurred on the site. In addition to the usual trades, we have crane operators, flagmen, truckers and special inspectors.”

He’s s still evaluating bottom-line costs.

“We are very happy with the quality of construction and the finished product — but we learned that smaller sites posed lots of difficulties — access, traffic management, proximity to neighbors,” said Kennedy who works with Pankow Builders of Oakland. “We might have saved some money building this conventionally, but we view this more as a research & development project — and in that capacity, it was very helpful and educating.”

Prefab construction probably makes more financial sense with larger projects (more units) on larger lots, Kennedy said. “If you don’t have space to work it gets very expensive very quickly.”

The goal — and hope — is that prefab will open the door to more affordable housing through lower construction costs. “We’re still trying to determine the optimal size. It’s a pretty new idea here in Northern California. We are learning as we go,” he said.

Kennedy said he knows of a few locations in the West Coast that sell similar modules, but they’re backlogged by years. So he went overseas. “The industry is evolving rapidly, and we are always looking to bring down costs. . . We would love to use local firms.” He built one previous prefab apartment project in San Francisco with a Sacramento manufacturer who is now out of business.

In lieu of providing affordable units on site, Kennedy will pay a fee to the city of Berkeley’s Affordable Housing Trust Fund, as required under the city’s affordable housing laws. The amount is around $500,000, he said.

In a few weeks, roughly four months from the start of construction, nearly two dozen UC Berkeley graduate students should be moving into the complex.

The units will rent for $2,180 monthly for single-occupancy, said Kyle Gibson, director of communications for UC Berkeley Capital Strategies. One unit is reserved for a residential assistant (RA). UC has a three-year lease with Kennedy’s firm.

Panoramic Interests will do building maintenance and cleaning.

Gibson said the university wasn’t involved in the design or construction, and he had no comment on the prefab approach. The project is one of several new developments recently completed or in the pipeline to increase student housing, he said. Some are university-built and owned, others leased.

“The University welcomes any and all projects and developments that expand the availability of affordable, accessible student housing in close proximity to campus,” Gibson said.

“It’s been an incredibly valuable tutorial for us. We know prefab is going to be the future, we just don’t know how we’re going to be part of it,” Kennedy said. “I’m chastened by the complexity of doing something so seemingly simple as stacking boxes on top of each other.”

Editor’s note: The headline on this story was changed after publication to make it more precise.