Amazon has submitted preliminary plans for the first part of its new headquarters in Arlington County, announcing that it will build a pair of 22-story office towers that meet high energy-efficient and environmental standards and include a public plaza and storage for 600 bicycles.

In a blog post Thursday, Amazon Vice President John Schoettler said the company is looking for “a sense of place . . . an urban campus that will allow our employees to think creatively, to be a part of the surrounding community, and to remain connected to the region’s unique culture and environment.”

(Amazon founder and chief executive Jeff Bezos owns The Washington Post.)

The 2.1 million square-foot project would house about 50,000 square feet of ground-floor retail space, including a day-care center serving employees and area residents. Just over an acre of open space would be built along Elm Street, according to preliminary plans filed with the county, and feature a dog park and a bicycle path that connects with existing bike paths.

A four-level, underground parking garage with 1,968 spaces is proposed, but the company also promises to provide each newly hired employee, part-time and full-time, with their choice of a Metro SmartTrip card, a year’s membership in a bike-share program or a year’s membership in a car-share program.

Amazon also indicated it would operate a carpool or vanpool program.

Despite early reports of Amazon’s interest in creating a helipad at its second headquarters, no landing site was evident in the plans.

The headquarters site, now home to vacant warehouses between 13th Street South and 15th Street South along Eads Street, was originally planned as a residential-retail project called Metropolitan Park.

Amazon’s change of use and its request for more height and density than current zoning allows will require County Board approval after it works its way through several planning steps.

Arlington County Board Chair Christian Dorsey (D) said he expects that a final version could come to the board for discussion by the end of the year. That’s also when the county will negotiate with Amazon to provide community benefits, such as money or space for affordable housing and other needs.

Neighborhood civic association leaders said they have yet to study the preliminary plans as submitted but have read news reports about them.

“Our general reaction is positive,” said Carol Fuller, president of the Crystal City Civic Association. “We had a meeting in April with [Amazon representatives] and all the area civic associations, and their plans sound good.”

Arthur Fox, of the Arlington Ridge Civic Association, who has opposed the project on the grounds that it will intensify density and traffic, said Friday that he and his neighbors want an independent cost-benefit analysis of the impacts. Fox also said his group would like to be in on the county’s negotiations with Amazon before “the cake is pretty much cooked.”

“Yes, we’re worried,” he said.

Based on the time needed to build other large developments in Arlington, the Amazon project will probably take two or three years to complete, although the company says its plans are moving along faster than expected.

The headquarters is the driving force behind plans to remake the Pentagon City-Crystal City-Potomac Yard neighborhoods, which the retail giant has jointly dubbed National Landing. The company plans to eventually employ 25,000 people at the campus, which will include other buildings and land in the surrounding neighborhood.

As part of that effort, Amazon plans to purchase the nearby PenPlace from its development partner, JBG Smith. That site was the subject of much discussion in 2013, when it was approved for five new office buildings, a hotel and retail space.