As the School of Medicine expands its faculty, the School of Public Health consolidates office space and the city’s biotech industry continues to grow, a new tower that promises to accommodate all three is on track for a June 2015 completion.

The space, located at 100 College Street and straddling the Route 34 Bridge, has been in construction for the past eight months. The 14-story building will house Alexion Pharmaceuticals, a producer of medications for extremely rare diseases, as well as the two Yale schools. The building is also one of the cornerstones of the Downtown Crossing project, an initiative that aims to connect downtown New Haven and the medical district while increasing commercial development.

The space will facilitate, collaboration, interdisciplinary research at the Yale School of Medicine and School of Public Health, said Paul Cleary, dean of the School of Public Health. The two floors of Yale space will not be turned into labs but rather will serve as an incubator for innovative research. Cleary said population-based research might be a potential area of inquiry, combining mathematical modeling and knowledge of infectious diseases.

Because recent growth in the two schools has scattered personnel around the city, both are eager to consolidate faculty, said Robert Alpern, dean of the School of Medicine.

“The idea is that we could use the space to bring all these people together in one building,” he said.

Most of the building will house Alexion, which was founded by Yale researchers in Science Park in 1992. In 2000, the company relocated to Cheshire, Conn., because New Haven did not offer enough laboratory space, said Irving Adler, Executive Director of Corporate Communications at Alexion. The company has continued to grow — entering the S&P 500 in May 2012 — and just over one year ago, it signed a 12-year lease for the 100 College Street space, said Carter Winstanley, a New Haven developer who has worked with the pharmaceutical company for the past 15 years. The building will allow the company to consolidate employees who are currently dispersed across multiple Cheshire buildings, Adler said.

Plans for the building itself began around seven years ago, said Bruce Alexander ’65, Vice President for State Affairs and New Haven and Campus Development. Alexander said Winstanley and Yale agreed to a 10-year lease for the space.

Alexion will occupy all but two of the building’s 14 floors, sharing the first floor with Yale, said Dan Caron, Vice President of Site Operations and Engineering at Alexion. Of the approximately 500,000 square feet in the building, Alexion will occupy about 400,000 square feet of laboratory and office space, he added.

Winstanley, the building’s developer, said the project promises to invigorate the local economy with thousands of new jobs, adding that it will also foster more indirect employment for nearby businesses.

Although Bloomberg News reported in July 2013 that Alexion might be bought by another pharmaceutical company, thereby abandoning the lease or only occupying the building for a short time, Adler said the company is here for the long haul and will honor its lease.

Alexion has more than 1,800 employees worldwide.