The Boston Redevelopment Authority has chosen Millennium Partners as the developers for the Winthrop Square Garage site on Devonshire Street.

The New York company, who is also responsible for the recently completed Millennium Tower in Downtown Crossing, was in competition with six other builders for the site.

Their offer of $151 million was much higher than any of the competitors and they were also chosen based on their record of building high-profile downtown buildings.

Millennium’s proposal consists of a 55-story tower with condos, office space and a three-story great hall at street level named ‘Boston’s living room’.

While finalized details are still being discussed, construction on the project is expected to cost $1 billion and start as soon as next summer.

The competing high-profile developers all had an impressive list of renowned architects pitching modern towers and various amenities, however Millennium Partners was the top choice, offering the most money and most impressive proposal.

The $151 million offered is also much more than the BRA have suggested the site is actually worth and it contributes a lot of money to the city.

On the site Millennium plans to build a 750-foot tower, which would be taller than all the towers in Boston except for the Hancock and Prudential towers.

The top 36 floors would be condos, there would be 14 stories of offie space below and then the street level great hall with retail, restaurants, and space always open to the public.

The BRA wanted a mixed-use project in Winthrop Square, especially coming from an experience developer able to execute complex projects.

Some issues still remain concerning the height guidelines put in place for the area and the BRA’s initial desire for an observation deck on the site.

If Millenniums bid turns out to not work with city official requirements then it would be possible for the BRA to go back and choose one of the other competitors.