Amazon unveiled plans Tuesday to build a futuristic building modeled after a double helix to serve as the centerpiece of its Arlington, Va., headquarters.

In artists’ renderings, the 350-foot-tall building — designed by the architectural firm NBBJ to reflect nature’s fondness for the helix in areas from DNA to the Milky Way galaxy — climbs above its National Landing neighborhood like the swirl on an ice cream cone or the tip of a giant screw that has punched through the Earth’s surface.

On social media, some likened the design to a Christmas tree. Others were reminded of Pieter Bruegel’s painting “The Tower of Babel.” Some, less impressed, thought it resembled the poop emoji. To many, however, almost anything was an improvement over the government-issue concrete boxes that have marked Crystal City’s skyline for years.

Amazon officials said the structure is intended to be an alternative workspace, not a traditional office building, where employees would be able to air out ideas and find downtime beyond their cubicles. Trees dot terraces along two walkways that spiral upward, evoking the feel of a stroll through the Blue Ridge Mountains. The streetscape below, with wood-frame retail pavilions and green space, is designed to appeal to people and keep them around when the workday ends.

Company officials said they want the corporate complex to blend with the neighborhood, offering features such as a community center, an amphitheater, a dog run, new bicycle lanes and 2.5 acres of green space that would be open to anyone. The Helix would include an artists-in-residence program and on occasional weekends would open its doors to the public.

“This isn’t just about work. It’s about how you interact with your community,” architect Dale Alberda, a principal of NBBJ, said during a news briefing.

Local government officials and community members responded to Amazon’s unveiling with guarded approval, frequently using the words “interesting” and “different” to describe their first impressions.

“I think we’ve been ready for some more interesting architecture in Arlington for a long time, so we’re definitely happy to see someone pushing the envelope there,” said Scott Miles, president of the Aurora Highlands Civic Association, who lives about seven blocks from the site. “Anytime something is new you get a whole range of reactions, and then once you think about it a little bit and live with it, you might come to some different thoughts on it.”

Arlington County Board Chair Matt de Ferranti (D) called the Helix “innovative,” expressing particular enthusiasm for the biophilic architectural design that fuses plants and trees with steel and glass.

“It’s going to be one of the first things you see when you come over the [14th Street] bridge,” said Michael Pickford, president of the Arlington Ridge Civic Association, whose neighborhood is about a mile and a half from the site. “So it’ll be nice to not have the brutalist concrete blocks that we currently have dotting our skyline in Crystal City.”

But Danny Cendijas, an organizer with La ColectiVa, part of the For Us, Not Amazon coalition, reacted to the company’s latest design with little more than a shrug. Of more concern, he said, is that Amazon and its founder, Jeff Bezos, have continued to amass stupendous wealth and power during a pandemic that has crushed others, and that the headquarters project has already produced some unpleasant side effects in the community.

Rents have risen, working-class people are being pushed out, and Virginia is still on course to pour $750 million in subsidies into the project.

“I think it’s more of the same,” Cendijas said.

Amazon’s site design still has a way to go before it becomes reality. De Ferranti said the next year will include several opportunities to go over the details in public and ask for public response before the submission comes before the Planning Commission and the County Board.

(Bezos, Amazon’s chief executive, owns The Washington Post.)

Amazon, which submitted plans Tuesday seeking county approval for the second phase of development, said the project emphasizes sustainability, including environmentally friendly buildings that maximize natural light and eventually would rely entirely on solar power for energy. (Employees would be able to open windows if they want.)

The Helix, together with three traditional office buildings in the PenPlace area of the second headquarters, would create about 2.8 million square feet of office space. The Helix is the tallest of the planned buildings and plays off the Spheres, a bio-inspired architectural design at the company’s headquarters in Seattle.

Construction on the Helix and related office complexes is expected to begin in 2022 and wrap by 2025.

Meanwhile, construction is underway on two eco-friendly office towers in the Metropolitan Park section of the complex. That area of the Arlington-based headquarters will create 2.1 million square feet of office space and about 65,000 square feet of retail space and other community features.

As of December, Amazon had already moved in more than 1,600 employees. The Arlington County Board signed off more than two years ago on development of the site, which has been dubbed National Landing and includes neighborhoods in Crystal City, Pentagon City and Potomac Yard. The Arlington headquarters is expected to accommodate 25,000 employees.

Amazon has said it intends to invest more than $2.5 billion in the county over the next decade. The expected influx into National Landing has already inflated housing prices in the area and sparked several new transportation projects, including expansion of Amtrak and Virginia Railway Express services. One booster organization has estimated that the new headquarters will create a $4 billion boom in public and private investments.

The tech company, which has been criticized in Seattle as a domineering neighbor that has overlooked the side effects of growth, such as gentrification and homelessness, has taken steps to win over Northern Virginia. The company donated $9 million last year to local nonprofit organizations, including health clinics, literacy projects and groups seeking to advance the cause of racial equity.

This month, the company’s Housing Equity Fund teamed with the nonprofit Washington Housing Conservancy to purchase Crystal House, an 825-unit apartment complex, as affordable housing.

“These are the areas that we call home, and it’s very important to us that we don’t just create an island unto ourselves, that we bring the community in,” said John Schoettler, Amazon’s vice president of global real estate and facilities.

correction

An earlier version of this article said the Helix will be 22 stories tall, but it will not have traditional stories. The building will be 350 feet tall.