Schnitzer photo

Google's offices in Bothell, Wash., would be near the University of Washington's satellite campus and a revitalized downtown.

Google has filed plans to add up to 840 workers at an office park north of Seattle, a dramatic expansion of its workforce on the home turf of Microsoft.

The search-engine giant already has offices in Seattle's Fremont neighborhood and in the nearby city of Kirkland.

Now Google intends to renovate offices at 11831 North Creek Parkway to accommodate further expansion, Joy Johnston, a spokeswoman for the city of Bothell, said.

Click here to see pictures of the campus.

The expansion would be located at an office park known as the Schnitzer North Creek Tech Campus, near Interstate-405, and the suburbs of Seattle.

The Bothell expansion comes as the city is undertaking a $150 million project to revitalize its downtown over the next five to 10 years, aiming to reduce speedy traffic by moving highways and creating a more liveable, walkable area, with a European style boulevard, a new city hall, restaurants and other amenities, Johnston said.

"Bothell is home to many successful companies, and it's exciting that Google will be joining them," Mayor Mark Lamb said in a statement.

"They're coming at a perfect time since Bothell is in the midst of revitalizing it's historic downtown, making it an even better place in which to live and work."

Google's proposed site is near the University of Washington's Bothell campus, and surrounded by other corporate offices, including biotech companies Seattle Genetics Inc., Sonus Pharmaceuticals and others.

"In the next five years the downtown is going to be completely different," Johnston said.

Update: Google confirmed that it there is a new facility, but wouldn't comment on further hiring or expansion plans.

"We've relocated a group of employees from our Kirkland office to a nearby facility," said a Google spokesperson.

Google's Seattle job board shows that it currently has a number of openings for software engineers, program managers and sales managers.