More than 100 graduate students are living in local hotel rooms as construction workers rush to finish reconstruction of their dormitory.

The 29 Garden Street building remains cloaked in white plastic sheets and crisscrossed with scaffolding, leaving many of the students skeptical that it will be completed by the extended October deadline set by the University.

The former hotel and Harvard University Police Department headquarters has been undergoing a “gut renovation” for the past 15 months, according to University spokesperson Lauren Marshall.

It was originally planned to be finished before move-in for this academic year.

When construction on the new dorm is complete, the dorm will contain 20 percent more space for students, as well as bathrooms and kitchens for most individual suites, a common dining hall and a green roof for students to use.

Because of greater than expected variation in the size and design of the building’s floors, the internal structure had to be gutted so that each of the stories could be rebuilt in a standard form, according to Marshall.

“There were unforeseen structural difficulties,” Marshall said of the almost century-old building. “It was worse than expected.”

“With older buildings it’s difficult to know the extent of problems,” she added. “Blueprints for older buildings are hard to find, so there has to be a discovery process.”

The site of the construction is gated off and covered with a large amount of scaffolding, which is in turn covered with white plastic sheets. Part of the building’s interior is visible and it is full of scaffolding.

Harvard is paying for hotel rooms for the 143 displaced students—many of whom are living at the Marriott in Kendall Square—until the dorm is finished.

“Harvard is really trying hard to accommodate us,” said first-year Law School student Erin Abrams.

While the University did not say how many students from each school were affected, those living at the Kendall Marriott said the Law School, the Education School, and the Kennedy School seem to be hit the hardest.

Sara J. Brenner, a first-year Law School student who is living alone in a Marriott bedroom, said she was “skeptical” that the dorm would be completed by October.

For Brenner, the free housing was “a tradeoff” because she would have to go through the hassle of moving mid-year.

And she said there were other drawbacks.