This month, Clayco, Inc., a major national development and construction company, announced it will move its national headquarters to Chicago, creating hundreds of new jobs. The company currently has about 1,000 employees total, with 280 employees in Chicago. Clayco expects to nearly double that Chicago number in the next couple of years by adding new architects, designers and project managers.

The new headquarters will be located in more than 30,000 square feet at 35 E. Wacker, also known as the Jewelers Building, in the heart of Chicago’s loop.

“Clayco is exactly the sort of company we are looking to attract to Chicago,” said Mayor Rahm Emanuel. “I am committed to bringing new and technologically advanced businesses to Chicago, especially those that want to grow and expand their businesses, and Clayco is exactly this sort of firm. I look forward to working with them as they make Chicago their new home.”

“Chicago is simply the best location for the company given our growing national and international design and engineering business,” said Clayco CEO Robert Clark. “The pro-growth, pro-business leadership of Mayor Emanuel, the incredible commitment to the city’s infrastructure and transportation hubs is second to none in the United States. In addition, for a growing company like ours to be in a world class city, attracting the best and brightest young minds in our industry, matches with our goals and objectives.”

Also this quarter, biopharmaceutical company Durata Therapeutics announced it will move its global headquarters to 200 S. Wacker Dr. from New Jersey, creating up to 100 new jobs over the next three years.

Founded in New Jersey, Durata is focused on the development and commercialization of novel therapeutics for patients with infectious diseases and acute illnesses. The three-year-old company went public in July.

Durata chose Chicago in order to access the city’s unique talent pool. The company will be a key player as Chicago’s biopharmaceutical sector continues to evolve. BioScience is one of the key areas of focus of ChicagoNEXT, a dedicated effort led by WBC to drive growth and opportunity in the business climates related to science, technology, innovation and entrepreneurship. The biotechnology industry’s largest global event, the BIO International Convention, will be held at Chicago’s McCormick Place in April.

“We also are quite familiar with Illinois’ deep talent pool in the pharmaceutical and hospital sectors. We look forward to recruiting many experienced employees to join our Chicago-based team over the coming years.” said Durata Therapeutics CEO Paul R. Edick.

In addition to Clayco and Durata, many other companies expanded or announced growth plans in Chicago over the past few months. Examples since December of 2012 include:

American Red Cross | Apollo Plastics Inc. | Aspen Foods | Avenues: The World School | Balton Corp | Bimbo Bakeries | Blackline Systems | Brightfarms Inc. | BT Warehouse/Cermak Produce | C5 | Caesarstone | Caherciveen Partners | Capital One | Cedar Concepts | Chango | Chicago Bulls | Chicago Children’s Museum | Chicago Sun Times | China Confidential | Choctaw-Kaul Distribution Company | Closerlook | Cornerstone Research | DePaul University | Diplomat Hotel | DunnhumbyUSA | Durata Therapeutics | DBT USA | Dynamite Data | Earthlink | Eleiko Sport Center | FarmedHere LLC | FLEx Lighting | General Electric | Ghafari | Grand Warehouse Corporation | Grant Thornton | H & M Hennes and Maurtiz L.P | Hainan Airlines | Hilton Chicago O’Hare | HomeFinder | Huron Consulting | Innovative Stone | Jump Operations | Kelly Scott Madison | LinkedIn | LSL Industries, Inc. | Lurie Children’s Hospital | Manasha Packaging Co | The Marketing Store Worldwide, LLC | Motel Sleepers, Inc | Networked Insights | New Enterprise Associates | Newly Weds Foods | Nokia | North Park University – Johnson Center for Science and Community Life | Northern Trust | Ogilvy Chicago | Optimal Strategix | PowerObjects | Presence Health | Prophet | Rapidrop | Resource Point of Sale | Sewer Tech | Signature Flight Support Corporation | Smith Electric Vehicles | Standard Parking | Swisse Vitamins | Tapad | UIC Advanced Chemical | | Technology Building | United Way | University of Chicago Medical Center | W.W. Grainger | Walgreen | Walgreen e-Commerce Institute | Workday | YMCA of Metropolitan Chicago | zColo | Zumber