Earlier this year Amazon submitted a building proposal to construct a series of massive biospheres in downtown Seattle adjacent to three other traditional office buildings as part of their new campus. The company received good news this week as the city's Design Review Board approved the design created by architectural firm NBBJ after they were convinced the unique structure would be engaging and inviting to the public.

The next step in the process involves the Seattle Department of Planning and Development which could approve the plans within the next couple of months according to the LA Times. Once complete, the new campus will consist of 3.3 million square feet of office and retail space spanning three city blocks bounded by Westlake Avenue, Blanchard Street and Sixth Avenue. The facility will also be connected by a streetcar line to Amazon's existing headquarters in the South Lake Union.

The five-story biospheres will feature 65,000 square feet of usable space for offices, retail space and a commons area based on early renderings. Amazon is even planning to offer a number of creature comforts and amenities including a public dog park. Three other 38-story office towers will occupy the remaining real estate, we're told.

The new office space should go a long way in helping to accommodate Amazon's ever-swelling employee base. At last check, the company had 97,000 employees on the payroll and has tripled in size over the past three years.